The Hausa Back Beliefs Questionnaire: Translation, cross-cultural adaptation and psychometric assessment in mixed urban and rural Nigerian populations with chronic low back pain.

INTRODUCTION: Negative attitudes and beliefs about low back pain (LBP) can lead to reduced function and activity and consequently disability. One self-report measure that can be used to assess these negative attitudes and beliefs and to determine their predictive nature is the Back Beliefs Questionnaire (BBQ). This study aimed to translate and cross-culturally adapt the BBQ into Hausa and assess its psychometric properties in mixed urban and rural Nigerian populations with chronic LBP.
METHODS: The BBQ was translated and cross-culturally adapted into Hausa (Hausa-BBQ) according to established guidelines. To assess psychometric properties, a consecutive sample of 200 patients with chronic LBP recruited from urban and rural clinics of Nigeria completed the questionnaire along with measures of fear-avoidance beliefs, pain catastrophizing, functional disability, physical and mental health, and pain. One hundred of the 200 patients completed the questionnaire twice at an interval of 7-14 days to assess test-retest reliability. Internal construct validity was assessed using exploratory factor analysis, and external construct validity was assessed by examining convergent, divergent, and known-groups validity. Reliability was assessed by calculating internal consistency (Cronbach's α), intraclass correlation coefficients (ICC), standard error of measurement (SEM), minimal detectable change at 95% confidence interval (MDC95), and limits of agreement using Bland-Altman plots. Reliability (ICC, SEM and MDC95) was also assessed separately for rural and urban subgroups.
RESULTS: The factor analysis revealed a four-factor solution explaining 58.9% of the total variance with the first factor explaining 27.1%. The nine scoring items loaded on the first factor hence supporting a unidimensional scale. The convergent and divergent validity were supported as 85% (6:7) of the predefined hypotheses were confirmed. Known-groups comparison showed that the questionnaire discriminated well for those who differed in education (p < 0.05), but not in age (p > 0.05). The internal consistency and ICC (α = 0.79; ICC = 0.91) were adequate, with minimal SEM and MDC95 (1.9 and 5.2, respectively). The limits of agreements were -5.11 to 5.71. The ICC, SEM and MDC95 for the urban and rural subgroups were comparable to those obtained for the overall population.
CONCLUSIONS: The Hausa-BBQ was successfully adapted and psychometrically sound in terms of internal and external construct validity, internal consistency, and test-retest reliability in mixed urban and rural Hausa-speaking populations with chronic LBP. The questionnaire can be used to detect and categorize specific attitudes and beliefs about back pain in Hausa culture to prevent or reduce potential disability due to LBP.

Introduction

Low back pain (LBP) is a common musculoskeletal disorder and presently the leading cause of disability in both developed and developing countries [1]. Nearly all individuals will, at some point in their life, experience LBP [2]. Although most episodes of LBP are benign in nature, some fraction of individuals may develop recurrent or chronic pain, which is accountable for the majority of direct and indirect costs associated with LBP [3]. Thus, chronic LBP is an important public health problem in the world necessitating attention in research, and effective health care [4].

Contemporary understanding suggests that LBP is a complex disorder associated with multiple contributors to both pain and related disability, including biophysical factors, psychosocial factors, comorbidities, and pain-processing mechanisms [5,6]. Specifically, psychosocial factors have been well documented to have a significant impact on pain persistence and the development of chronic disability [7-11]. Moreover, the impact of psychosocial factors does not only include pain experience but also treatment outcomes and consequently recovery [12,13].

One important modifiable psychological factor related to LBP disability is back pain beliefs. According to Vlaeyen et al. [14], negative beliefs about back pain, are often viewed as a signal of an impending threat, which leads to fear of movement/(re)injury, decreased function and activity, and consequently persistent chronic disability. In support of this notion, results of several cross-sectional studies suggest that negative beliefs about back pain are associated with persistent, high levels of pain and disability [15-18], care-seeking behavior [19], work absenteeism, and reduced productivity [20-22]. Additionally, studies have shown that back pain beliefs are influenced by culture [23] and demographic characteristics such as age, education level, and working environment [16,24,25].

The Back Beliefs Questionnaire (BBQ) developed by Symonds et al. in 1996 [20] is a widely used self-reported outcome to assess attitudes and beliefs towards recovery and return-to-work. The questionnaire has been used as an outcome to test the effectiveness of interventions targeting back pain beliefs [26-28]. Furthermore, it has been shown to predict recovery rate from LBP [29]. The original English BBQ proved to be valid and reliable [20,30], and has been adapted and validated for use in several languages/cultures [31-41].

The three main indigenous languages in Nigeria are Hausa, Igbo, and Yoruba. Recently, the BBQ was successfully adapted into Yoruba [42]. However, no Hausa version of this tool is available despite Hausa being the largest ethnic group not only in Nigeria but also in sub-Saharan Africa with about 80 million speakers [43]. The language is commonly spoken in Benin, Cameroon, Chad, Central African Republic, Eritrea, Equatorial Guinea, Gabon, Gambia, Ghana, Ivory Coast, Niger, Republic of the Congo, Senegal, Sudan, and Togo [44]. Adapting the BBQ into Hausa will enhance the uptake of studies in these regions as it may assist researchers and clinicians to detect negative attitudes and beliefs about back pain and design appropriate interventions. Therefore, this study aimed to translate and cross-culturally adapt the BBQ into Hausa and assess its psychometric properties in mixed urban and rural Nigerian populations with chronic LBP.

Methods

Ethical considerations

This study was approved by the Health Research Ethics Committee, Kano State Ministry of Health, Nigeria (Ref: MOH/Off/797/T.I./651). Written permission to translate the English version of the BBQ into Hausa was obtained from the original developers. Written informed consent was obtained from all participants before their involvement in the study.

Study design

This cross-sectional study was conducted in two stages: Translation and cross-cultural adaptation of the BBQ into Hausa; and assessment of psychometric properties of the translated version.

Outcome measures

Back Beliefs Questionnaire (BBQ)

The BBQ is a 14-item scale, with each item rated using a 5-point Likert scale ranging from strongly disagree (1) to strongly agree (5). Five of the items (4, 5, 7, 9, and 11) are distractors and nine items (1, 2, 3, 6, 8, 10, 12, 13, and 14) are used for scoring of the questionnaire resulting in a total score ranging from 9 to 45 [20]. The score obtained for each item is reversed (for example 5 means 1, and 2 means 4) before summing to obtain the final score meaning the lower the scores, the more pessimistic beliefs regarding the consequences of back pain [20]. The original English BBQ demonstrated excellent internal consistency (Cronbach’s α: 0.70) and test-retest reliability (intraclass correlation coefficients [ICC]: 0.87).

Hausa Fear-avoidance Beliefs Questionnaire (FABQ)

The FABQ assesses fear-avoidance beliefs about physical activity and work [45]. It consists of 16 items, with each item rated using a Likert scale ranging from 0 (completely disagree) to 6 (completely agree). The questionnaire has two subscales: physical activity subscale (FABQ-physical activity) and work subscale (FABQ-work), with four and seven items, respectively, and five remaining items as ineffective. Each subscale scores are summed to obtain a total score with possible scores of 0 to 24 for the FABQ-physical activity subscale and 0 to 42 for the FABQ- work subscale. Higher scores indicate greater fear-avoidance beliefs [45]. The Hausa version of the FABQ has been validated [46].

Hausa Pain Catastrophizing Scale (PCS)

The PCS assesses thoughts and feelings about pain [47]. It consists of 13 items, with each item rated using a 5-point Likert scale ranging from 0 (not at all) to 4 (all the time). The scores obtained for each item are summed to obtain the total scores ranging from 0 to 52, with higher scores indicating more catastrophic thoughts [47]. The Hausa version of the PCS demonstrated acceptable reliability and construct validity [48].

Hausa Oswestry Disability Index (ODI)

The ODI assesses perceived levels of functional disability [49]. It consists of ten categories, of which each is having six statements scored from 0 to 5. Scores obtained for each category are summed and divided by the number of completed categories to obtain a final score ranging from 0 to 100, with higher scores indicating greater disability [49]. The Hausa version of the ODI 2.1a has been validated [50].

Hausa Short-form Health Survey (SF-12)

The SF-12 is a generic measure of health-related quality of life [51]. It consists of 12-item, designated into eight domains from which two global health constructs (physical and mental health) are derived. Each item is rated using response categories. The response categories vary from 2 to 6 and raw scores for items ranging from 1 to 6. A web-based scoring tool (www.orthotoolkit.com/sf-12/) was used to calculate the physical and mental component scores expressed in percentage, with higher scores indicating better health status. The Hausa version of the SF-12 has been validated [52].

Hausa Visual Analogue Scale for pain (VAS-pain)

The VAS is widely used to assess levels of pain intensity. It consists of a 100mm horizontal line anchored on the left with the phrase ‘‘No Pain” and on the right with the phrase ‘‘Worst Imaginable Pain”. A higher score indicates greater pain intensity [53]. Patients were asked to mark at a point on the line that corresponds to their current pain. The Hausa version of the VAS-pain was found to be reliable [54].

Translation and cross-cultural adaptation

The translation and cross-cultural adaptation process followed the guidelines proposed by Beaton et al. [55] and the entire process consisted of six stages as follows:

Initial translation: Two independent bilingual (English and Hausa) translators, whose mother tongue is Hausa, forward translated the original English BBQ into Hausa, resulting in two versions (T1 and T2). The first translator (NBM) was a clinical physiotherapist and aware of the purpose of the study and the questionnaire concept whereas the second translator (TA) was a linguist and neither aware nor informed about the concept being examined.

Synthesis of the translation: The translators (T1 and T2) and the lead author discussed discrepancies of the translated versions using the original English version as reference. Following consensus, a synthesized version (T12) was then produced.

Back translation: Two independent bilingual translators (IMI and IU) with no medical or clinical background and blinded to the original English version translated the synthesized version (T12) back into English, resulting in two back translations (BT1 and BT2).

Expert committee review: An expert committee involving both the forward and backward translators, one academic physiotherapist (BK) with proficiency in methodology, and the lead author compared and consolidated all the translated versions (T1, T2, T12, BT1, BT2) taking into account achieving cross-cultural equivalence. This stage ensured face validity and resulted in the prefinal version of the Hausa BBQ for field-testing.

Test of the prefinal version: The prefinal version was tested among 20 patients (11 males and 9 females; mean age = 47 years) with non-specific CLBP and equal representation of urban (n = 10) and rural (n = 10) community. Each participant was asked to provide feedback about clarity and interpretability of the questionnaire items and chosen responses. All problematic items, responses, statements, phrases, and words were resolved at this stage. The committee ensured that the original meaning of the questionnaire was not altered or lost while attaining cross-cultural equivalence. This stage ensured the content validity and led to the production of the final version of the Hausa BBQ (Hausa-BBQ).

Proofreading: A professional translator independently proofread the final version for any errors that may have been missed in the previous stages. The final version (see S1 Appendix) along with the reports of the translation process was then sent to the original developers of the questionnaire for appraisal. No further modifications were necessary.

Assessment of psychometric properties

The procedure used throughout this section has been used in the cross-cultural adaptation of other Hausa self-report measures as reported elsewhere [48,50,52].

Population

Generally, consensus about the ideal sample size for validating a scale is unclear. However, the Consensus-based Standards for the selection of health Measurement Instruments (COSMIN) checklist suggest that a sample size of ≥ 100 patients is adequate for psychometric assessments [56]. In the present study, 200 patients were recruited to assess the psychometric properties of the Hausa-BBQ adequately.

The study was conducted purposely in one tertiary health facility (Murtala Muhammad Specialist Hospital [MMSH]), and three secondary health facilities (Dawakin-Kudu General Hospital [DGH], Wudil General Hospital [WGH], and Kura General Hospital [KGH]), all in Kano State, Northwestern Nigeria. These facilities were selected to recruit both urban and rural patients. The patients were consecutively recruited into the study at the physiotherapy outpatient unit in each of these facilities between February and May 2018. The inclusion criteria were adults aged between 18 to 70 years, with primary complain of non-specific LBP ≥ 12 weeks and fluent in Hausa language. Participants were excluded if their LBP was due to serious spine pathologies such as fracture, infection, inflammatory disease, malignancy, and osteoporosis. Patients with a history of previous spine surgery, cognitive impairment or impaired capacity to be interviewed, and pregnancy were also excluded.

Procedure for data collection

Four licensed physiotherapists with between two to five years of clinical experience were recruited from the selected health facilities and received a one-day training session on data collection procedures. The session was organized by the lead author for the physiotherapists to familiarize themselves with the collection of data using interviewer-administration method since a significant proportion of Hausa patients particularly rural dwellers are non-literates [50,52]. The physiotherapists, in each of the study settings, were responsible for eligibility assessments, which included history taking and screening of ‘red flags to exclude serious spinal pathology. After applying informed consent, the participants’ demographic and clinical characteristics were collected and recorded.

Statistical analysis

To assess validity, 200 rural and urban patients completed the Hausa-BBQ along with the Hausa FABQ, PCS, ODI, SF-12 health survey, and VAS-pain. The measures were administered via interviewer-administration or self-administration method where applicable. To assess test-retest reliability, the Hausa-BBQ was re-administered among 100 patients who participated in the validity testing. Measurements were repeated 7 to 14 days after the initial measurement.

All statistical analyses were conducted using IBM SPSS for Windows version 24.0 (IBM Corp, Armonk, NY). Normality of the data was assessed using visual inspection of distribution plots, and Kolmogorov-Smirnov and Shapiro-Wilk’s tests. Descriptive statistics of mean, standard deviation (SD), frequencies, and percentages were used to summarize the data. Specific statistical techniques used to assess the psychometric properties of the Hausa-BBQ were as follows:

General aspects and ceiling and floor effects

Potential missing values were evaluated by cross-checking all the items to ensure that respondents did not leave any item unanswered. Ceiling or floor effects are considered if more than 15% of respondents scored the maximum or minimum possible scores, respectively [57]. Potential “ceiling and floor effects were assessed by calculating the percentage of the patients obtaining the maximum (ceiling) or minimum (floor) BBQ scores.

Internal construct validity

Factorial structure was assessed using exploratory factor analysis (EFA) by applying principal component analysis with orthogonal Varimax rotation. Kaiser-Meyer-Olkin (KMO) test and Bartlett’s test of sphericity were applied to determine sampling adequacy for appropriateness of the factor analysis. A significant Bartlett’s test (p < 0.05) and KMO value of > 0.6 were considered acceptable [58]. Since the BBQ is well known to be a unidimensional scale, we hypothesized that the factorial validity of the Hausa-BBQ would be supported if the nine scoring items (9-item scores) loaded significantly (factor loading coefficients ≥ 0.4) on one underlying factor [36,38].

External construct validity

Convergent and divergent validity were assessed by correlating the Hausa-BBQ scores with the scores of other measures. Predefined hypotheses of association were formulated based on the findings of previous validation studies. For the convergent validity, we hypothesized that the BBQ would have low to strong negative correlations with the FABQ-physical activity (r or rho = –0.30 to –0.57) [34,35,38] and FABQ-work (r or rho = –0.29 to –0.55) [34,38]; low to moderate negative correlations with the PCS (r or rho = –0.30 to –0.50) [35] and ODI (r or rho = –0.30 to –0.42) [33,36,38]; and low to moderate positive correlations with the PCS-12 (r or rho = 0.28 to 0.50) [33] and MCS-12 (r or rho = 0.23 to 0.50) [33]. For the divergent validity, we hypothesized that the BBQ would correlate weakly with the VAS-pain (rho = –0.14 to –0.34) [33,35,38]. The construct validity is supported when at least 75% (≥ 5) of the predefined hypotheses are confirmed [57]. Pearson’s correlation coefficient (r) was applied for normally distributed variables while Spearman’s correlation coefficient (rho) was applied for non-normally distributed variables. Correlation coefficients were interpreted as “strong/high” (0.51–1.00), “moderate” (0.31–0.50), and “weak/low” (0.10–0.30) [59,60].

Known-groups validity was assessed by comparing the mean Hausa-BBQ scores of different patient groups based on age (younger adults: 18–24; adults: 25–44; midlife adults: 45–64, and older adults: ≥ 65 years) [52] and education (non-formal education, completed primary education, completed secondary education, and completed tertiary education) [48,50,52] using one-way analysis of variance (ANOVA). We hypothesized that younger [25] and non-literate (non-formal education) [24] patients would have more pessimistic beliefs about back pain.

Item analysis

The item analysis included inter-item correlations, corrected item-total correlations, and Cronbach’s α if item deleted. Inter-item correlations and corrected item-total correlations were examined to determine item redundancy, with correlations of 0.30–0.70 being considered satisfactory [61]. Pearson’s correlation coefficient was applied for the inter-item correlations Cronbach’s α if item deleted was calculated to determine internal consistency (homogeneity of items). Cronbach’s α coefficients were interpreted as “inadequate” (< 0.70), “adequate” (0.70–0.79), “good” (0.80–0.89), and “excellent” (> 0.90) [62]. We hypothesized that the Cronbach’s α coefficients for the Hausa-BBQ would lie within the range of 0.70–0.82 to be considered acceptable [31,33,36,40,42].

Test-retest reliability

Test-retest reliability (temporal stability) was assessed by calculating ICC with 95% confidence intervals (CI) for agreement. ICC values were interpreted as “poor” (< 0.40), “fair” (0.40–0.59), “good” (0.60–0.74), and “excellent” (> 0.75) [62]. We hypothesized that the ICC for the Hausa-BBQ would lie within the range of 0.70–0.89 to be considered acceptable [31,32,35,37,41].

As per the recommendation of COSMIN [63], absolute reliability was assessed by calculating standard error of measurement (SEM) and minimal detectable change at 95% CI (MDC95). The SEM was calculated by taking the square root of the mean square error term from the reliability ANOVA output. Subsequently, the MDC95 was calculated by multiplying the SEM by 2.77. The MDC95 provides the minimum values considered true change beyond measurement error [64,65]. We hypothesized that the SEM and MDC95 for the Hausa-BBQ would lie within the range of 2.1–3.8 [33,36,42] and 5.9–10.5 [35,36,42], respectively. Additionally, 95% limits of agreement (LOA95%) were calculated with Bland-Altman plots by plotting the difference between test and retest of Hausa-BBQ scores against the mean scores of the test and retest. This was done for both the global and 9-item scores. We hypothesized that the LOA95% for the Hausa-BBQ would lie within the range of –10.0 to +12.6 [31,34,42]. Subgroup reliability analyses regarding ICC, SEM and MDC95 for urban and rural patients were also performed.

Results

The Hausa-BBQ was easily adapted as there were no major forward or backward translation issues. However, during the pilot testing, some patients expressed difficulty in choosing the applicable response number as the original English version has only two descriptors; completely disagree (1) and completely agree (5). Hence, for clarity, the expert committee reached a consensus to add descriptors “disagree”, “neutral”, and “agree” for response numbers 2, 3, and 4, respectively. The expert committee ensured that the Hausa-BBQ attained semantic, idiomatic, experiential, and conceptual equivalence with the original English version. All the questionnaire items were reported to be clear and comprehensive.

Psychometric assessment

Demographic and clinical characteristics

The mean age of the patients was 45.5±14.5 years. There were 123 (61.5%) males and 77 (38.5%) females. The majority of the patients were residing in rural areas (60.0%) and unemployed (64.0%). Slightly over half of them had non-formal education (33.0%) and were non-literates in Hausa (55.5%). The demographic and clinical characteristics of the patients across validity and reliability are fully presented in Table 1.

Table 1

Demographic and clinical characteristics of the study population.

Characteristics	Validity (n = 200)	Reliability (n = 100)
Age, years, mean ± SD	45.5 ± 14.5	46.3 ± 14.7
Gender, n (%), male: female	123 (61.5), 77 (38.5)	61 (61.0), 39 (39.0)
Habitation, n (%), urban: rural	80 (40.0), 120 (60.0)	42 (42.0), 58 (58.0)
Marital status, n (%), married: unmarried	157 (78.5), 43 (21.5)	80 (80.0), 20 (20.0)
Educational status, n (%)
Non-formal education	66 (33.0)	32 (32.0)
Completed primary education	30 (15.0)	16 (16.0)
Completed secondary education	41 (20.0)	18 (18.0)
Completed tertiary education	63 (31.5)	34 (34.0)
Literacy (ability to read and write in Hausa), n (%)
Non-literate	111 (55.5)	54 (54.0)
Literate	89 (44.5)	46 (46.0)
Occupational status, n (%)
Employed	49 (24.5)	23 (23.0)
Unemployed	128 (64.0)	65 (65.0)
Student	17 (8.5)	10 (10.0)
Retiree	6 (3.0)	2 (2.0)
BBQ, mean ± SD (global score, range 14–70)	36.0±7.24	37.3±5.70
BBQ, mean ± SD (9-item score, range 9–45)	23.2±5.42	23.9±5.23
FABQ-physical activity, mean ± SD (score range 0–42)	13.1±5.80	-
FABQ-work, mean ± SD (score range 0–24)	23.4±7.77	-
PCS, mean ± SD (score range 0–52)	30.0±8.21	-
PCS-12, mean ± SD (score range 0–100)	34.5±6.94	-
ODI, mean ± SD (score range 0–100)	37.2±13.2	-
MCS-12, mean ± SD (score range 0–100)	38.8±10.1	-
VAS-pain, mean ± SD (score range 0–100mm)	41.3±13.1	-

SD, standard deviation; BBQ, Back Beliefs Questionnaire; FABQ, Fear-avoidance Beliefs Questionnaire; PCS, Pain Catastrophizing Scale; ODI Oswestry Disability Index; PCS-12, Physical Component Summary; MCS-12, Mental Component Summary; VAS-pain, Visual Analogue Scale for pain.

All the participants completed the Hausa-BBQ without missing values yielding a response rate of 100%. The response rate of the questionnaire according to the recruitment sites were 78 (39.0%), 47 (23.5%), 39 (19.5%), and 36 (18.0%) in the MMSH, DGH, WGH, and KGH, respectively. No ceiling and floor effects were observed for the questionnaire global scores or 9-item scores. However, for the individual items, ceiling effects (higher scores) were found for item 4, whereas floor effects (lower scores) were found for items 2, 5, 7, 9, 11, 12, 13, and 14 (Table 2). The response trend for each item of the Hausa-BBQ does not deviate from normal distribution as none of the items exhibited skewness > 1.96 (Table 2).

Table 2

General characteristics of the Hausa Back Beliefs Questionnaire (n = 200).

		Range	Mean (SD)	Ceiling effects n (%)	Floor effects n (%)	Skewness
1	There is no real treatment for back trouble	1–5	2.66 (0.88)	10 (5.0)	16 (8.0)	0.457
2	Back trouble will eventually stop you from working	1–5	2.77 (1.33)	30 (15.0)	47 (23.5)	0.218
3	Back trouble means periods of pain for the rest of one’s life	1–5	2.69 (0.98)	11 (5.5)	26 (13.0)	0.190
4	Doctors cannot do anything for back trouble	1–5	3.06 (1.36)	48 (24.0)	28 (14.0)	0.131
5	A bad back should be exercised	1–5	2.51 (1.47)	18 (9.0)	85 (42.5)	0.245
6	Back trouble makes everything in life worse	1–5	2.52 (0.82)	2 (1.0)	26 (13.0)	–0.214
7	Surgery is the most effective way to treat back trouble	1–5	2.42 (1.13)	11 (5.5)	57 (28.5)	0.325
8	Back trouble may mean you end up in a wheelchair.	1–5	2.72 (0.96)	6 (3.0)	29 (14.5)	–0.117
9	Alternative treatments are the answer to back trouble	1–5	2.30 (1.16)	7 (3.5)	69 (34.5)	0.419
10	Back trouble means long periods of time off work	1–5	2.68 (0.95)	6 (3.0)	24 (12.0)	0.055
11	Medication is the only way of relieving back trouble	1–5	2.53 (1.17)	18 (9.0)	71 (35.5)	0.275
12	Once you have had back trouble there is always a weakness	1–5	2.41 (0.94)	2 (1.0)	42 (21.0)	–0.029
13	Back trouble must be rested	1–5	2.28 (0.83)	1 (0.5)	39 (19.5)	0.012
14	Later in life back trouble gets progressively worse	1–5	2.54 (0.98)	9 (4.5)	33 (16.5)	0.282
	Global scores	14–70	36.0 (7.24)	60 (0.5)	18 (0.5)	–0.062
	9-item scores	9–45	23.2 (5.42)	39 (0.5)	10 (0.5)	–0.033

SD, standard deviation.

The KMO value was adequate (0.754) and Bartlett’s test of sphericity was significant (χ = 794.8, df = 91, p = 0.000) signifying appropriateness of the factor analysis. The principal component analysis revealed a 4-factor structure explaining 58.9% of the total variance (Table 3). The nine scoring items loaded on factor 1 except for item 8, which loaded on factor 3. The distractor items loaded on factor 2 except item 4, which loaded on factor 4. None of the distractor items loaded on the same factors as the nine scoring items (Table 3). The internal consistency as measured by the Cronbach’s α of the nine scoring items was 0.72, and 0.79 after the removal of item 8 indicating that the items still maintain homogeneity within the scale.

Table 3

Factor structure of the Hausa Back Beliefs Questionnaire.

Statement		Coefficients ≥ 0.4
		Factor 1	Factor 2	Factor 3	Factor 4
1	There is no real treatment for back trouble	0.486*	0.048	0.614	0.104
2	Back trouble will eventually stop you from working	0.600*	0.140	–0.283	0.120
3	Back trouble means periods of pain for the rest of one’s life	0.797*	–0.021	0.219	–0.108
4	Doctors cannot do anything for back trouble	0.051	0.193	–0.147	0.750*
5	A bad back should be exercised	0.034	0.432*	–0.258	–0.648
6	Back trouble makes everything in life worse	0.519*	0.143	0.338	0.163
7	Surgery is the most effective way to treat back trouble	0.125	0.730*	0.117	0.402
8	Back trouble may mean you end up in a wheelchair.	0.129	0.081	0.781*	–0.064
9	Alternative treatments are the answer to back trouble	0.124	0.834*	0.050	0.023
10	Back trouble means long periods of time off work	0.575*	0.061	0.252	–0.053
11	Medication is the only way of relieving back trouble	–0.025	0.848*	0.039	–0.156
12	Once you have had back trouble there is always a weakness	0.537*	0.117	0.187	0.050
13	Back trouble must be rested	0.696*	0.018	–0.101	0.140
14	Later in life back trouble gets progressively worse	0.757*	–0.065	0.257	–0.144
	% variance explained	27.1	15.1	9.0	7.7

The normality analyses revealed that the BBQ, PCS-12, and MCS-12 were normally distributed whereas the FABQ-PA, FABQ-W, PCS, and VAS-pain had skewed distribution. Consistently with the convergent hypotheses, the Hausa-BBQ demonstrated a low negative correlation with FABQ-PA (rho = –0.18, p > 0.012), FABQ-W (rho = –0.21, p > 0.003), and PCS (rho = –0.20, p > 0.004) except with the ODI (rho = –0.21, p > 0.003); and a low positive correlation with the PCS-12 (r = 0.24, p > 0.001) and MCS-12 (r = 0.23, p > 0.001). As for the divergent hypotheses, the Hausa-BBQ demonstrated a low negative correlation with the VAS-pain (rho = –0.19, p > 0.006) as expected. The correlational analyses indicate that 85% (6:7) of the predefined hypotheses were confirmed.

Known-groups comparison showed that the Hausa-BBQ did not significantly discriminate between patients with different age groups (p > 0.05) (Table 5). However, the questionnaire significantly discriminates between patients with different education levels (p < 0.05). Patients with non-formal education demonstrated lower BBQ scores (Table 4).

Table 5

Internal consistency and test-retest reliability of the Hausa Back Beliefs Questionnaire.

Hausa-BBQ	Internal consistency	Test-retest (repeatability)				SEM	MDC95
	Cronbach’s α if item deleted	Test (t1) Mean SD	Retest (t2) Mean SD	t1-t2	ICC (95% CI)
Overall population	0.78	23.9 (5.23)	24.2 (4.46)	–0.30†	0.91 (0.86–0.94)	1.9	5.2
Urban population	-	23.4 (3.92)	24.1 (3.97)	–0.71†	0.89 (0.80–0.94)	1.7	4.6
Rural population	-	24.2 (6.01)	24.2 (4.81)	–0.00†	0.91(0.86–0.95)	2.1	5.9

BBQ, Back Beliefs Questionnaire; ICC, intraclass correlation coefficient; CI, confidence interval; SEM, standard error of measurement; MDC, minimal detectable change.

†p > 0.05.

Table 4

Known-groups validity of the Hausa Back Beliefs Questionnaire.

	Age group
	18–24	25–44	45–64	≥ 65
	Mean (SD)	Mean (SD)	Mean (SD)	Mean (SD)	F-ratio	p-value	ηp2
BBQ (9–45)	24.6 (5.40)	23.4 (5.22)	22.9 (5.31)	22.9 (6.38)	0.532	0.661	0.01
	Education level
	Non-formal	Primary	Secondary	Tertiary
	n (%)	n (%)	n (%)	n (%)	F-ratio	p-value	ηp2
BBQ (9–45)	21.6 (5.63)	24.0 (6.24)	23.8 (5.02)	24.1 (4.69)	2.951	0.034*	0.04

BBQ, Back Beliefs Questionnaire; SD, standard deviation; ηp2, partial eta squared.

*p < 0.05.

The inter-item correlations were < 0.70, except for the correlation between item 3 and 14 (r = 0.73), suggesting multicollinearity. However, since the correlation between these items was not considerably high and deleting any of the items significantly reduced the Cronbach’s α, we decided to retain all the items to maintain the scale structure. The scale’s corrected item-total correlations were 0.14–0.57, with low corrected item-total correlations being observed for item 8 (< 0.30), indicating redundancy. The Cronbach’s α if item deleted was 0.75. Deletion of item 8 slightly increased the Cronbach’s α (0.78) (Table 5).

Test re-test reliability

As shown in Table 5, the ICC for the overall population was excellent (ICC = 0.91; 95% CI = 0.86–0.94), with minimal SEM and MDC95 (1.9 and 5.2, respectively). The mean difference (–0.30) of the repeated measurements was not statistically significant (p > 0.05). As for the subgroup analyses, the ICC, SEM, and MDC95 calculated for the urban (n = 42) and rural (n = 58) populations were comparable to the overall population (Table 6). The Bland-Altman analysis for the overall population showed a mean difference and LOA95% of –0.30 and –5.11 to +5.71 (Fig 1).

Table 6

Summary of psychometric properties of the published adapted Back Beliefs Questionnaire.

First author, year	Adapted to	na	Int. cons.	Test-retest reliability					nb	Construct validity (r or rho)c	Factor Analysis
			α	Days	ICC	SEM	MDC	LOA		Measure	Model	R2
Teixeira, 2020 [31]	Brazilian Portuguese	26	0.70	7–14	0.74	4.0	11.1	−10.5 to +12.0	26	-	-	-
Mbada, 2020 [42]	Yoruba (Nigerian)	51	0.71	7	0.89	2.3	6.4	−0.684 to +5.70	119	VAS = 0.27	3, 2	44.9, 36.2
Rajan, 2020 [37]	Marathi (Indian)	43	0.67	15	0.80	-	-		50	RMDQ = –0.29	-	-
Tingulstad, 2019 [35]	Norwegian	63	0.82	1–13	0.71	3.8	10.5		116	NRS = −0.14; RMDQ = –0.29; FABQ-PA = −0.57; PCS = −0.45	-	-
Karaman, 2019 [38]	Turkish	25	0.79	7	0.84	-	-		110	NRS = −0.34; ODI = −0.42; FABQ-PA and W = −0.55; HADS-anxiety = −0.46; HADS-depression = −0.32	3	52
Cheung, 2018 [33]	Traditional Chinese (Hong Kong)	100	0.81	-	-	-	-		100	VAS = − 0.32; ODI = −0.34; FABQ-PA = −0.34; FABQ-W = − 0.29; PF = 0.27; RP = 0.39; BP = 0.22; GH = 0.32; VT = 0.30; SF = 0.28; RE = 0.27; MH = 0.24; PCS-12 = 0.28; MCS-12 = 0.23	-	-
Dupeyron, 2017 [39]	French	121	0.80	1–7	0.64	-	-		128	VAS = −0.15; Tampa = –0.66; FABQ = −0.52; Quebec = −0.31; Dallas = −0.24 to −0.43; HADS-anxiety = −0.28; HADS-depression = −0.42	-	-
Maki, 2017 [34]	Modern Arabic (Bahrain)	64	0.73	7	0.80	-	-	−8.00 to +12.6	199	FABQ = −0.33; FABQ-PA = −0.30; FABQ-W = −0.29	-	-
Alamrani, 2016 [36]	Arabic (Saudi Arabia)	25	0.77	1−8	0.88	2.1	5.9		115	NRS = −0. 10; ODI = −0.31	3	46
Elfering, 2015 [41]	German	151	0.80	4–13	0.89	-	-		2225	-	3	48
Suzuki, 2012 [40]	Japanese	-	0.82	-	-	-	-		127	WPAI = −0.26; RMDQ = −0.20; NRS = −0.04	-	-
Chen, 2011 [32]	Simplified Chinese (Shanghai)	65	0.70	1−10	0.85	-	-		65	VAS = –0.04; HC-PAIRS = 0.40; FABQ-PA = 0.48; FABQ-W = 0.49	-	-

Int. cons, internal consistency; α, Cronbach’s alpha; ICC, intraclass correlation coefficient; SEM, standard error of measurement; MDC, minimal detectable change, VAS, Visual Analogue Scale; RMDQ, Roland-Morris Disability Questionnaire; NRS, Numerical Rating Scale; ODI, Oswestry Disability Index; FABQ-PA, Fear-Avoidance Beliefs Questionnaire-Physical activity; FABQ-W, Fear-Avoidance Beliefs Questionnaire-work; PCS, Pain Catastrophizing Scale; HADS, Hospital Anxiety and Depression Scale, PF, Physical Functioning; RP, Role Physical; BP, Bodily Pain; GH, General Health; VT, Vitality; SF, Social Functioning; RE, Role Emotional; MH, Mental Health; PCS-12, Physical Component Summary; MCS-12, Mental Component Summary; HC-PAIRS, Health Care Providers’ Pain and Impairment Relationship Scale; WPAI, Work Productivity and Activity Impairment Questionnaire.

aTest-retest reliability sample size.

bConstruct validity and internal consistency (α) sample size.

cMeasures used to evaluate construct validity of BBQ using Pearson’s product correlation (r) or Spearman’s rank correlation (rho).

R2Total variance explained.

Fig 1

Bland-Altman plot for test-retest agreement of Hausa-BBQ.

Discussion

The original English BBQ was successfully adapted into Hausa without major translation problems similar to many previous adaptations [36-38]. The questionnaire was comprehensive, clear, and easy to complete thus demonstrating good face and content validity. The absence of missing values could be ascribed to the interviewer-administration method used in the study, besides the effort of the raters to ensure that none of the questionnaire items was left unanswered including those who completed the questionnaire in self-administered format. No ceiling neither floor effects were detected for both the global and 9-item scores. However, ceiling effects were found for item 4 as most patients disagree that doctors cannot do anything for back trouble. Likewise, floor effects were detected for items 2, 5, 7, 9, 11, 12, 13, and 14 indicating poor discriminating ability as most patients have lower scores (more pessimistic beliefs about LBP) in these items. These findings could be partly explained by the fact that a plurality of the studied population (33.0%) had non-formal education. In line with our study, ceiling and floor effects were found in some of the items of the French adaptation [39].

Regarding factorial validity, only a few studies [36,38,41,42] have examined the underlying structure of the BBQ (Table 6) even though the questionnaire was originally designed as a unidimensional scale [20]. Though our factor analysis revealed a four-factor solution, surprisingly, the one-factor structure is supported as the nine scoring items loaded on the first factor except for item 8 “Back trouble may mean you end up in a wheelchair”, which loaded on the third factor. The result that item 8 was not loaded on the first factor might be attributed to the different interpretations for the item among the studied population. As expected, the distractor items loaded on the second factor except item 4 “Doctors cannot do anything for back trouble”, which loaded on the fourth factor. The finding that the one-factor structure is supported is in line with the original English version [20]. Although studies exploring the factor structure of the BBQ consistently revealed a three-factor structure [30,36,38,41,42], interestingly, most of these studies [36,38,41] found the nine scoring items loaded on the first factor solution while the distractors loaded on the two other factor solution resembling the findings of the present study.

To examine convergent and divergent validity of the Hausa-BBQ, various specific hypotheses were constructed, and on this basis, the construct validity is supported as 85% (6 out of 7) of the predefined hypotheses were confirmed. Overall, the convergent validity of the Hausa-BBQ was demonstrated, with significant correlations with the FABQ-PA, FABQ-W, PCS, PCS-12, and MCS-12. While the BBQ and FABQ scales measure beliefs about LBP, the low correlations observed between these scales may be attributed to the fact that they measure a construct that is not similar to each other [36]. The correlation between the Hausa-BBQ and ODI (rho = –0.21) was not at least moderate as hypothesized, even though was significant. It is anticipated that low knowledge about LBP would be associated with more disability. The low correlations observed can be explained by the inverse relationship between these scales, besides only 25% of the studied population were workers. Hence, it can be speculated that unemployed patients may not be concerned with back pain consequences beliefs related to work. To the best of our knowledge, only the Norwegian adaptation [35] assessed the correlation between the BBQ and PCS (Table 6). In the present study, the correlation (rho = –0.24) between these measures was lower than that found for the Norwegian version (rho = –0.45) [35]. Similar to the Traditional Chinese adaptation [33], low positive correlations were found between the Hausa-BBQ and the PCS-12 and MCS-12, hence, establishing evidence of the association between pessimistic beliefs about LBP and physical as well as mental health. Further, the low negative correlation observed with the VAS-pain confirms discriminative validity. Thus, it can be inferred that beliefs about negative consequences of LBP may not be exclusively related to pain intensity. In line with our study, low or no correlations (r or rho = –0.04 to –0.15) between back beliefs and pain intensity were generally reported in the literature [32,35,36,39,40,66].

The results of the known-groups validity revealed that patients with non-formal education had lower BBQ scores, which implies more pessimistic beliefs about LBP, and the ability of the questionnaire to discriminate well for patients who differed in education. This is in concordance with previous studies demonstrating an association between back pain beliefs and education levels [24,25]. Clinicians should therefore consider reshaping patients’ beliefs about LBP using effective education strategies. On the contrary, we found no significant relationship between age groups and the BBQ scores suggesting that the questionnaire was unable to discriminate against patients who differed in age. In line with this finding, previous studies did not find age to be an important correlate of back beliefs [16,24].

Internal consistency calculated for the Hausa-BBQ (α = 0.78) was adequate considering the acceptable value of 0.70 [57]. Our alpha coefficient is slightly higher than the 0.70 reported for the original English measure [20], and the range of 0.67−0.77 reported by many language versions [31,32,34,36,37,42,43]. Other adaptations, however, reported slightly higher alpha coefficients (α range = 0.79–0.82) [33,35,38,39,40] (Table 6). Though item 8 shows redundancy (weak correlation < 0.30) as also revealed by the factor analysis, deletion of this item, however, did not significantly improve the internal consistency (α = 0.75 vs. 0.78), hence, this item may still be included in computing the scores of the Hausa-BBQ to retain the original structure of the questionnaire. Moreover, the multicollinearity (high correlation > 0.70) detected between items 3 and 14 suggests that these items may be measuring the same aspect of inevitable beliefs.

Test-retest reliability of the Hausa-BBQ demonstrated a highly significant correlation (ICC = 0.91), suggesting acceptable reliability. Remarkably, our ICC was higher than the value (0.87) obtained for the original English version [20] and the range of 0.64–0.89 reported by several translated versions [31,32,34-38,41,42] (Table 6). Additionally, the ICC values obtained for the urban and rural subgroups in the present study were also excellent and comparable to those obtained for the overall population. This suggests that our questionnaire is reliable when used in different contexts. It should be noted, however, that ICC only takes into account between-subject variability but not measurement error [67]. Only four of the twelve BBQ adaptations (Table 6) calculated measurement error expressed as SEM and the resultant MDC95. In the present study, these reliability indicators were minimal (SEM = 1.9; MDC95 = 5.2) when compared to the Brazilian-Portuguese (SEM = 4.0; MDC95 = 11.1) [31] and Norwegian (SEM = 3.8; MDC95 = 10.5) [35] versions but somewhat comparable to the Arabic (SEM = 2.1; MDC95 = 5.9) [36] and Yoruba (SEM = 2.3; MDC95 = 6.4) [42] versions. Also, the SEM and MDC95 values obtained for the urban and rural subgroups were comparable to those obtained for the overall population, thus supporting the applicability of the Hausa-BBQ in both rural and urban Nigeria. The MDC95 is an essential measurement property as it indicates a true change in a patient’s score beyond measurement error. For example, when using the Hausa-BBQ (0–45) as an outcome measure, an observed change greater than 5.2 points can be considered a real change whereas an observed change less than 5.2 points cannot be distinguished from measurement error.

Although the Bland-Altman plot method does not reveal whether the limits are acceptable but defines the intervals of agreements, the smaller the range between two limits the better the agreement. The LOA95% calculated for the Hausa-BBQ showed a good distribution of scores as the mean difference was close to zero with few outliers. Compared to the LOA95% range of –10.0 to +12.6 observed in previous validations [31,34,42], our range (–5.71 to +5.11) was smaller, suggesting good agreement with minimal systematic bias. This indicates that researchers and clinicians can have confidence when administering the Hausa-BBQ that the measurements will not be diluted by systematic bias or random error. Moreover, given that the minimal important change (MIC) for the BBQ has not been determined, the MDC95 and the LOA95%, though should not replace the MIC, can be used to interpret a change in BBQ scores following interventions targeting negative beliefs about LBP.

The strength of this study is that the psychometric assessment of the Hausa-BBQ is in line with COSMIN guidelines [56,63]. Moreover, both rural and urban patients with different literacy levels were recruited to have wide applicability of the questionnaire. However, one potential limitation of this study is that we could not guarantee that some patients did not receive or seek treatment during the recruitment or retesting period, which may influence their back beliefs. The majority of the respondents were interviewer-administered which might increase measurement error or overestimate the clearness and readability of the questionnaire. Furthermore, we did not perform confirmatory factor analysis, and responsiveness (sensitivity to change) to determine MIC. Future studies are therefore needed to evaluate these important psychometric properties.

Conclusions

The results of this study suggest that the Hausa-BBQ was successfully adapted and psychometrically sound in terms of internal and external construct validity, internal consistency, and test-retest reliability in mixed urban and rural Hausa-speaking populations with chronic LBP. The questionnaire can be used to detect and categorize specific attitudes and beliefs about back pain in Hausa culture to prevent or reduce potential disability due to LBP.

Hausa version of BBQ.

(PDF)

Click here for additional data file.

The Hausa-BBQ validity data (n = 200).

(XLSX)

Click here for additional data file.

The Hausa-BBQ reliability data (n = 100).

(XLSX)

Click here for additional data file.

5 Jan 2021

PONE-D-20-31974

The Hausa back beliefs questionnaire: Translation, cross-cultural adaptation and psychometric assessment in mixed urban and rural Nigerian populations with chronic low back pain

PLOS ONE

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Reviewer #1: I reviewed this validation study of a nice scale like BBQ. There are some parts that need to be corrected. You can find my suggestions below.

1)General

Please review for spelling and grammatical mistakes.

2) Abstract

It's been too long. it should be summed up more briefly.

3)İntroduction

The paragraph that starts as “Most developed patient-reported… “ and gives general information about PROMs contains unnecessary information. This paragraph can be omitted.

“Nigeria is Africa's most populous….” This paragraph as was also lengthened unnecessarily. In this paragraph, the necessity of the hausa version should be stated more briefly.

4) Methods

Cronbach and ICC values given for the original BBQ are not in excelent ranges. Look again, which value corresponds to which range.

No reference is given to the PCS hausa version.

The first paragraph in “Assessment of outcomes” was also very unnecessary. We can take it out in this part.

The ranges corresponding to the correlation coefficients cut off values are not correctly defined. Examine the literature better and determine the intervals correctly.

5) Discussions

Problems with translation, already described in the result, have been repeated. Remove it from one of the two parts.

A lot of information given in the result has been repeated in the discussion. In the discussion, features differentiated from previous studies should be highlighted.

Reviewer #2: Abstract: The following sentence is unclear. «Known-groups comparison showed that the

questionnaire discriminated well for those who differed in education (p < 0.05) but age

(p > 0.05).». What is meant by global BBQ-score ? Does the global BBQ score include the distractor items ?

Introduction page 12: back pain altitudes should be changed into back pain attitudes (« and clinicians to identify back pain altitudes and beliefs and design appropriate interventions»)

Methods : What does conveniently recruited mean ? (« The participants were conveniently recruited into the study »). Please report the participation rates in four different hospitals. What about the treatment of patients ? Patients who received behavioral cognitive therapy should be excluded, because change of their BBQ is a goal in therapy.

It is unclear why the distractor items were included in some testings what author(s) label test of global BBQ score (e.g., « Known-groups validity: Known-groups validity was assessed by comparing the global and 9-item scores with age and education levels using one-way ANOVA.

Morover, in exploratory factor analysis, the distractor items were included, too. Inclusion of distractor items in factor analysis blurres the results. A confirmatory factor analysis that tests the 9 items of the BBQ is a better test of the on-factor-structure.

Results : Please report differences in BBQ mean levels between four samples. It is surprising that no missing values were observed. Do the author(s) have an explanation ?

Reviewer #3: General comment: very interesting paper, well written and well structured. The statistical analysis is varied, and results brings new data. The conclusion answers correctly the scientific question addressed here.

Comment 1: Abstract is too long to my opinion.

C2: Why do the authors claim that they need 100 subjects and have planned to recruit 200?

C3: The questionnaires were administered a second time at D7-D14. How can the authors guarantee that no intervention was done during this delay prone to change patients' health status?

C4: I suggest moving the table 1 to e-addenda as I guess all readers will not be interested by these technical considerations.

C5: Method: This section is difficult to follow. Please clarify. I would suggest reordering the undersections. For example, first a few lines on the questionnaire with the global method; second, the translation procedure; third, the population and the authorization; fourth, the validation with the design of the study and content of the validation (dimensions explored in your study); fifth, the stats. The section results is very easy to follow, a similar construction may help (to my opinion).

C6 Method: I suggest limiting the number of tables in the article and for example delete the table 1 and move the informations in the text in the method section or the discussion.

C7 Method section/stats/Point 4/ Line3: The authors talk about table 2 relating result from previous studies. Please check.

C8 The design is not clear for the validity and the reliability not presented as different in the method section and separated in the results. Please check. The method used needs to as clear as possible. Was it the same sample for both?

C9 Table 3: I suggest deleting the column Highest and lowest score, useless.

C10: Why Table 7 is before Table 5? Please check all the tables and reorder.

C11 Discussion: Item 4 is not related to wheelchair.

C12 Discussion, Paragraph 4: “In the present study, a low negative correlation between these measures was found contrary to the Norwegian adaptation [35] where a moderate correlation was established.” What does “contrary” mean here: opposite (positive correlation) or intensity (low vs moderate)? Please clarify

C13 Discussion Paragraph 6: Table 8 does not refer to the factor structure, please check.

C14 Discussion paragraph 6: “In a similar passion” does not look appropriate in a scientific report.

C15 Discussion paragraph 6: The authors found a one factor solution for the nine item scoring. Item 4 (only ceiling effect detected) loaded on the fourth factor. Item 8 (wheelchair) loaded on the third one. The internal consistency is not graphically represented, and I wonder if the item 8 is useful for interpretation (last items on the Cronbach scheme). A figure representing the explanation part per item in this scpecific case may likely be interesting.

C16 Discussion Last paragraph: “The major limitation is the lack of cause effects relationship of the intervention”. It is not a therapeutic intervention, so it is difficult to understand.

C17 Conclusion: Consider that the BBQ is not directly useful for prevention or reduction of LBP consequences but more for detection and categorization of specific consequences of low back pain.

C18 Table 6: please check the SD value of the 18-24 group.

C19: Congratulations to the authors, very nice work.

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Reviewer #3: Yes: Arnaud Dupeyron

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29 Jan 2021

Response letter to the reviewer's comments for the manuscript (PONE-D-20-31974) submitted to PLOS ONE

Response to Reviewer #1

Dear reviewer,

We would like to thank you for the time you spent reviewing our manuscript entitled “The Hausa back beliefs questionnaire: Translation, cross-cultural adaptation and psychometric assessment in mixed urban and rural Nigerian populations with chronic low back pain”.

You can find all the modifications/changes [text highlighted in red (deletions) and purple (additions/corrections)] in the revised file (marked version).

Please find below our response to your constructive comments/suggestions.

Comment 1 (General):

Please review for spelling and grammatical mistakes.

Response/amendments:

Spelling and grammatical mistakes were reviewed and corrected throughout the manuscript.

Comment 2 (Abstract):

It's been too long. it should be summed up more briefly.

Response/amendments:

The abstract has been reduced as you suggested.

Comment 3 (Introduction):

a. The paragraph that starts as “Most developed patient-reported… “and gives general information about PROMs contains unnecessary information.

b. This paragraph can be omitted.“Nigeria is Africa's most populous…” This paragraph as was also lengthened unnecessarily. In this paragraph, the necessity of the Hausa version should be stated more briefly.

Response/amendments:

a. The paragraph was omitted as you suggested.

b. The paragraph modified/reduced

Comment 4 (Methods):

a. Cronbach’s and ICC values given for the original BBQ are not in excellent ranges. Look again, which value corresponds to which range.

b. No reference is given to the PCS Hausa version.

c. The first paragraph in “Assessment of outcomes” was also very unnecessary. We can take it out in this part.

d. The ranges corresponding to the correlation coefficients cut off values are not correctly defined. Examine the literature better and determine the intervals correctly.

Response/amendments:

a. The range of the accepted values of Cronbach’s α and ICC for the BBQ has been revised based on the range of values defined in the literature and those reported in similar validation studies (for a priori hypotheses).

b. The reference to Hausa version of the PCS is now added.

c. The first paragraph under “Assessment of outcomes” was modified/reduced rather than deleted because we think that is important to describe how the data of the questionnaires were collected. Different hospitals and different raters were used. Moreover, interviewer administration method was utilized as majority (60%) of the respondent were non-literates.

d. The ranges of the correlation coefficients cut off values were revised and updated as you suggested.

Comment 5 (Discussion):

a. Problems with translation, already described in the result, have been repeated. Remove it from one of the two parts.

b. A lot of information given in the result has been repeated in the discussion. In the discussion, features differentiated from previous studies should be highlighted.

Response/amendments:

a. Problems with translation were removed from the discussion as you suggested.

b. Repeated information in the discussion were removed where necessary and features differentiated from previous studies were highlighted as suggested.

Once again, we thank you for all your constructive suggestions/comments. Indeed, your review has significantly improved our manuscript.

Note: Grammatical errors, typographic errors and technicalities were corrected throughout the manuscript.

Thank you.

Sincerely.

Response to Reviewer #2

Dear reviewer,

We would like to thank you for the time you spent reviewing our manuscript entitled “The Hausa back beliefs questionnaire: Translation, cross-cultural adaptation and psychometric assessment in mixed urban and rural Nigerian populations with chronic low back pain”.

You can find all the modifications/changes [text highlighted in red (deletions) and purple (additions/corrections)] in the revised file (marked version).

Please find below our response to your constructive comments/suggestions.

Comment 1 (Abstract):

a. The following sentence is unclear. «Known-groups comparison showed that the questionnaire discriminated well for those who differed in education (p < 0.05) but age

b. What is meant by global BBQ-score? Does the global BBQ score include the distractor items?

Response/amendments:

1. The statement “Known-groups comparison showed that the questionnaire discriminated well for those who differed in education (p < 0.05) but age (p > 0.05)” implies that the comparison of the patients’ BBQ scores according to their education status (subgroup) was statistically significant suggesting that the questionnaire may be able to differentiate patients’ pessimistic beliefs based on their education status. However, for the age variable, the comparison was not statistically significant suggesting that the questionnaire cannot differentiate patients’ pessimistic beliefs according to their age.

2. Yes, the global or total BBQ score means the scores for all the questionnaire items (14 items) including the distractors.

Comment 2 (Introduction):

Page 12: back pain altitudes should be changed into back pain attitudes (« and clinicians to identify back pain altitudes and beliefs and design appropriate interventions»)

Response/amendments:

Many thanks for your observation. It was out of sight and has been corrected.

Comment 3 (Methodology):

a. What does conveniently recruited mean? (« The participants were conveniently recruited into the study »).

b. Please report the participation rates in four different hospitals.

c. What about the treatment of patients? Patients who received behavioral cognitive therapy should be excluded, because change of their BBQ is a goal in therapy.

d. It is unclear why the distractor items were included in some testings what author(s) label test of global BBQ score (e.g., « Known-groups validity: Known-groups validity was assessed by comparing the global and 9-item scores with age and education levels using one-way ANOVA.

e. Moreover, in exploratory factor analysis, the distractor items were included, too. Inclusion of distractor items in factor analysis blurres the results. A confirmatory factor analysis that tests the 9 items of the BBQ is a better test of the on-factor-structure.

Response/amendments:

a. We wanted to say “consecutively recruited” instead. This has been corrected.

b. Sincerely, it will be difficult for us to report the precise participation rates in the four different hospitals as the questionnaires were mixed and we did not indicate the address or hospital name on each of the questionnaires.

c. None of the patients received cognitive behavioral therapy (even though we did not mention this in the inclusion/exclusion criteria). However, we could not rule out that some patients received other treatments most especially electrotherapy or exercise.

d. We have now excluded the global BBQ score from external construct validity (convergent, divergent, and known-groups validity) and reliability analyses (internal consistency, ICC, SEM, MDC95, and LOA95%) as inclusion of the distractors items is not relevant since they are not included in computing the BBQ scores.

e. Generally, when conducting EFA of a measure, all items are included to have an insight of the putative structure including the distractors’ items will verify the underlying structure of the BBQ. This was also done in all the adaptions that examined EFA of the BBQ (e.g. the Arabic, Turkish and Yoruba versions) However, when it comes to CFA, the distractors are not included since the purpose is to verify the underlying latent constructs (i.e. the 9 scoring items of the BBQ).

Comment 4 (Results):

a. Please report differences in BBQ mean levels between four samples.

b. It is surprising that no missing values were observed. Do the author(s) have an explanation?

Response/amendments:

a. As we previously stated (response to point 3b above), it will be difficult for us to report the mean of the four samples separately.

b. Potential missing values were evaluated by the raters (physiotherapists) as most of the questionnaires were interviewer-administered. It was done by cross-checking all the items to ensure that respondents did not leave any item unanswered. The raters received training prior to the data collection and they were reminded that all questions should be checked for missing values.

Once again, we thank you for all your constructive suggestions/comments. Indeed, your review has significantly improved our manuscript.

Note: Grammatical errors, typographic errors and technicalities were corrected throughout the manuscript.

Thank you.

Sincerely.

Response to Reviewer #3

Dear reviewer,

We would like to thank you for the time you spent reviewing our manuscript entitled “The Hausa back beliefs questionnaire: Translation, cross-cultural adaptation and psychometric assessment in mixed urban and rural Nigerian populations with chronic low back pain”.

You can find all the modifications/changes [text highlighted in red (deletions) and purple (additions/corrections)] in the revised file (marked version).

Please find below our response to your constructive comments/suggestions

Comment 1: Abstract is too long to my opinion.

Response/amendments: The abstract is now reduced as you suggested.

Comment 2: Why do the authors claim that they need 100 subjects and have planned to recruit 200?

Response/amendments: Yes, 100 subjects is the minimum recommended by COSMIN and Terwee et al (2007) guidelines, however, the patients were recruited as part of the lead author PhD project to cross-culturally adapt and validate low back pain measures (e.g. ODI, RMDQ, SF-12. FABQ, NPRS, PCS e.t.c.) not only the BBQ, into Hausa. Adaptation of these measures requires adequate sample size especially when conducting Rasch analysis, EFA and CFA as large sample size is generally recommended to obtain robust and precise item parameter estimates.

Comment 3: The questionnaires were administered a second time at D7-D14. How can the authors guarantee that no intervention was done during this delay prone to change patients' health status?

Response/amendments: This is one of the limitations of our study and we have mentioned it in the discussion aspect. We cannot guarantee that no intervention was given during the test-retest period, however, due nature of clinic schedules in our environment, where patients are usually given weekly (once per week) or two-weekly (once per two weeks) appointment/follow-up, we, therefore, believe that even if the patients have received an intervention, it may not significantly affect the patients’ health status.

Comment 4: I suggest moving the table 1 to e-addenda as I guess all readers will not be interested by these technical considerations

Response/amendments: We deleted Table 1 since it is not that important and we have many tables in the manuscript.

Comment 5: Method: This section is difficult to follow. Please clarify. I would suggest reordering the under sections. For example, first a few lines on the questionnaire with the global method; second, the translation procedure; third, the population and the authorization; fourth, the validation with the design of the study and content of the validation (dimensions explored in your study); fifth, the stats. The section results is very easy to follow, a similar construction may help (to my opinion).

Response/amendments: The methods section is now modified for clarity.

Comment 6: Method: I suggest limiting the number of tables in the article and for example delete the table 1 and move the information in the text in the method section or the discussion.

Response/amendments: Table 1 was deleted and the contents were moved in the text in the method section (statistical analyses) as you suggested. Reviewer #1 also suggested limiting the number of tables.

Comment 7: Method section/stats/Point 4/ Line 3: The authors talk about table 2 relating result from previous studies. Please check.

Response/amendments: It was out of sight. We have corrected this.

Comment 8: The design is not clear for the validity and the reliability not presented as different in the method section and separated in the results. Please check. The method used needs to as clear as possible. Was it the same sample for both?

Response/amendments: The same sample was used for the validity and reliability. In the method section, we clearly explain this for clarity.

Comment 9: Table 3: I suggest deleting the column Highest and lowest score, useless.

Response/amendments: Highest and lowest score columns in Table 3 were deleted as you suggested.

Response/amendments: The same sample was used for the validity and reliability. In the method section, we clearly explain this for clarity.

Comment 10: Why Table 7 is before Table 5? Please check all the tables and reorder.

Response/amendments: All tables were checked and reordered as you suggested.

Comment 11: Discussion: Item 4 is not related to wheelchair.

Response/amendments: Thank you for observing this error. The sentence is now corrected.

Comment 12: Discussion, Paragraph 4: “In the present study, a low negative correlation between these measures was found contrary to the Norwegian adaptation [35] where a moderate correlation was established.” What does “contrary” mean here: opposite (positive correlation) or intensity (low vs moderate)? Please clarify

Response/amendments: The paragraph has been corrected for clarity.

Comment 13: Discussion Paragraph 6: Table 8 does not refer to the factor structure, please check

Response/amendments: Table 8 is now Table 7. There is a column (last) for the factor structure of the BBQ assessed by previous studies, hence we cited the table.

Comment 14: Discussion paragraph 6: “In a similar passion” does not look appropriate in a scientific report.

Response/amendments: The phrase “In a similar passion” was replaced with “in the same vein”

Comment 15: Discussion paragraph 6: The authors found a one-factor solution for the nine item scoring. Item 4 (only ceiling effect detected) loaded on the fourth factor. Item 8 (wheelchair) loaded on the third one. The internal consistency is not graphically represented, and I wonder if the item 8 is useful for interpretation (last items on the Cronbach’s scheme). A figure representing the explanation part per item in this specific case may likely be interesting.

Response/amendments: We agree that since item 8 did not load on the first factor (9 scoring item factor), it may has an ambiguous meaning to the population, hence, not measuring the same construct as the other eight items. Surprisingly, the retaining or removal of this item did not significantly changed the alpha coefficients (i.e. α = 0.75 vs. 0.78), hence this may justify retaining the item in BBQ scoring. For item 4, we are not so bothered since it belongs to the distractor items, and retaining or deleting the item did not significantly changed the alpha coefficients (i.e. 0.722 vs. 0.743) for the whole questionnaire (global score). We commented on this briefly in the discussion section. The ICC and other reliability as well as validity analyses for the whole questionnaire was deleted based on the recommendation of other reviewer that distractor items are not used in scoring the BBQ.

Below is the internal consistency analysis output from SPSS (for 9-item score)

Item-Total Statistics

Scale Mean if Item Deleted Scale Variance if Item Deleted Corrected Item-Total Correlation Cronbach's Alpha if Item Deleted

BBQ-Q1 20.59 23.842 .561 .765

BBQ-Q2 20.48 23.155 .340 .806

BBQ-Q3 20.56 22.137 .684 .746

BBQ-Q6 20.73 24.681 .503 .773

BBQ-Q8 20.53 25.456 .313 .796

BBQ-Q10 20.57 23.844 .507 .771

BBQ-Q12 20.84 24.390 .449 .778

BBQ-Q13 20.97 24.818 .474 .776

BBQ-Q14 20.71 22.508 .638 .752

Below is the internal consistency analysis output from SPSS (for global score)

Item-Total Statistics

Scale Mean if Item Deleted Scale Variance if Item Deleted Corrected Item-Total Correlation Cronbach's Alpha if Item Deleted

BBQ-Q1 33.405 46.323 .438 .698

BBQ-Q2 33.295 44.480 .333 .708

BBQ-Q3 33.380 44.518 .523 .687

BBQ-Q4 33.005 49.030 .077 .743

BBQ-Q5 33.550 48.982 .058 .750

BBQ-Q6 33.550 46.701 .445 .699

BBQ-Q7 33.645 44.160 .458 .692

BBQ-Q8 33.350 47.957 .258 .715

BBQ-Q9 33.770 44.047 .448 .693

BBQ-Q10 33.390 46.018 .422 .698

BBQ-Q11 33.535 44.632 .317 .711

BBQ-Q12 33.655 46.458 .391 .702

BBQ-Q13 33.785 47.124 .397 .703

BBQ-Q14 33.530 45.175 .468 .693

Comment 16: Discussion Last paragraph: “The major limitation is the lack of cause effects relationship of the intervention”. It is not a therapeutic intervention, so it is difficult to understand.

Response/amendments: We deleted the statement regarding such limitation since it is understood that our study is not interventional as you suggested.

Comment 17: Conclusion: Consider that the BBQ is not directly useful for prevention or reduction of LBP consequences but more for detection and categorization of specific consequences of low back pain.

Response/amendments: Thank you for the constructive suggestion. We modified the conclusion while taking note of the BBQ is rather used for detection and categorization of specific consequences of low back pain as you suggested.

Comment 18: Table 6: please check the SD value of the 18-24 group.

Response/amendments: It was out of sight and has been corrected.

Comment 19: Congratulations to the authors, very nice work.

Response: Once again, we thank you for all your constructive suggestions and comments. Indeed, your review has significantly improved our manuscript.

Note: Grammatical errors, typographic errors and technicalities were corrected throughout the manuscript.

Thank you.

Sincerely.

Submitted filename: Response to Reviewers-Hausa-BBQ.docx

Click here for additional data file.

2 Mar 2021

PONE-D-20-31974R1

The Hausa Back Beliefs Questionnaire: Translation, cross-cultural adaptation and psychometric assessment in mixed urban and rural Nigerian populations with chronic low back pain

PLOS ONE

Dear Dr. Ibrahim,

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Academic Editor

PLOS ONE

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: All comments have been addressed

Reviewer #3: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

**********

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The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: No

**********

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PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

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6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: I reviewed the article with the changes made. Necessary corrections have been made. The article can now be accepted.

Reviewer #2: Author(s) should add to their limitations can not identify the four hospitals in questionnaires and check for potential bias. Author8s) should also add to their limitations that the data collection was interview-based. Interview-based data collection might overestimate the clearness and readability of the questionnaire.

Reviewer #3: I would like to thank the authors for their extensive effort to improve the text. They have correctly answered my questions and comments.

Some minor comments for the revised manuscript:

1. Once again, the lines are not numbered and it is difficult to localize the comments

2 Translation and cross-cultural adaptation section: I suggest to give the name of the "translators" (initials if authors or full names)

3 Translation and cross-cultural adaptation section, last sentence: The authors claim having sent the final version to the original developers and what happened?

4 I Would suggest to replace "sample size estimation" by "population" and move the two last sentences (patients needed for reliability and validity before statistical analysis) in this section.

5 In the result section does not need to report the results in the text and in the table (external validity for example) please choose one or the other.

6 Discussion, first paragraph: for Item 4 a ceiling effect would likely mean that patients believe that doctors are unable to help them. Please check.

7 The discussion is interesting.

**********

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Reviewer #1: Yes: Okan Lüçükakkaş

Reviewer #2: No

Reviewer #3: Yes: Arnaud Dupeyron

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6 Mar 2021

Response to Reviewer #1

Dear reviewer,

Once again, we would like to thank you for the effort and time you spent reviewing our manuscript.

Sincerely.

Response to Reviewer #2

Dear reviewer,

We would like to thank you for the effort and time you spent reviewing our manuscript for the second time.

1. We have now added the response rate of the questionnaire according to the four hospitals (SEE General aspect, ceiling and floor effects, in the results section) as you suggested.

2. The limitation regarding interviewer-administration method was added in the discussion section as suggested.

You can find all the modifications/changes [text highlighted in red (deletions) and purple (additions/corrections)] in the revised file (marked version).

Sincerely.

Response to Reviewer #3

Dear reviewer,

We appreciate the effort and time you spent reviewing our manuscript for the second time.

You can find all the modifications/changes [text highlighted in red (deletions) and purple (additions/corrections)] in the revised file (marked version).

Please find below our response to your constructive comments/suggestions

Comment 1: Once again, the lines are not numbered and it is difficult to localize the comments

Response/amendments: We apologize for this. The numbering is supposed to be handled by the journal electronic submission process so that reviewers may be able to see the lines numbered for easy reference. However, we have added the numbering in the revised files.

Comment 2: Translation and cross-cultural adaptation section: I suggest to give the name of the "translators" (initials if authors or full names)

Response/amendments: We have now provided the initials of the forward and backward translators.

Comment 3: Translation and cross-cultural adaptation section, last sentence: The authors claim having sent the final version to the original developers and what happened?

Response/amendments: The final version of the Hausa-BBQ along with the report of the translation process was sent to the original developers for appraisal. The developers responded and there was no need for further modifications. We have now indicated this in the manuscript (SEE item 6: Proofreading).

Comment 4: I would suggest to replace "sample size estimation" by "population" and move the two last sentences (patients needed for reliability and validity before statistical analysis) in this section

Response/amendments: We replaced “Sample size estimation” with “Population” as you suggested.

Comment 5: In the result section, does not need to report the results in the text and in the table (external validity for example) please choose one or the other.

Response/amendments: The modifications were done. Table 5 was deleted and the order of the tables was reflected.

Comment 6: Discussion, first paragraph: for Item 4 a ceiling effect would likely mean that patients believe that doctors are unable to help them. Please check

Response/amendments: The sentence was checked but ceiling effects means higher scores (disagree, as the scores are reversed) and this indicate that most patients had higher scores for item 4 (Doctors cannot do anything for back trouble), [mean score (SD) = 3.06 (1.36) as shown in Table 2]. Since the scores are reversed, the interpretation will be that most of the participants disagree or do not believe that doctors cannot do anything for back trouble.

Comment 7: The discussion is interesting.

Response: Once again, we thank you for all your constructive suggestions and comments.

Sincerely.

Submitted filename: Response to Reviewers-Hausa-BBQ-R2.docx

Click here for additional data file.

17 Mar 2021

The Hausa Back Beliefs Questionnaire: Translation, cross-cultural adaptation and psychometric assessment in mixed urban and rural Nigerian populations with chronic low back pain

PONE-D-20-31974R2

Dear Dr. Ibrahim,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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Kind regards,

Adewale L. Oyeyemi, Ph.D

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

A very good manuscript that would make important contribution to the field. I am wondering if the authors can consider the inclusion of their questionnaire as a supplement to the manuscript.

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #2: All comments have been addressed

Reviewer #3: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #2: Yes

Reviewer #3: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #2: Yes

Reviewer #3: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #2: Yes

Reviewer #3: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #2: Yes

Reviewer #3: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #2: The author(s) addressed all my comments successfully. The ms improved considerably. Author(s) might think of adding their questionnaire as supplement to their paper.

Reviewer #3: No more comment. Just a suggestion in the method section: In the population paragraph delete "participants" which is covered by "population"

**********

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Reviewer #2: No

Reviewer #3: Yes: Arnaud DUPEYRON

5 Apr 2021

PONE-D-20-31974R2

The Hausa Back Beliefs Questionnaire: Translation, cross-cultural adaptation and psychometric assessment in mixed urban and rural Nigerian populations with chronic low back pain

Dear Dr. Ibrahim:

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