Development and validation of Vellore Inventory of Life Skills among people with severe mental illness.

BACKGROUND AND AIM: Rehabilitation for people with severe mental illness is incomplete without life skills assessment and intervention. The aim of the study was develop a culturally specific performance-based measure assessing life skills of patients with severe mental illness.
MATERIALS AND METHODS: The items for the Vellore Inventory of Life Skills (VILS) were drawn after consultation with a reference group and from existing standardized scales. The items were categorized into two sections with six components each, which was further hierarchically arranged into activities at either basic, intermediate, or advanced level. One hundred consecutive clients between 18 and 60 years of age who provided written informed consent were assessed on the Comprehensive Evaluation of Basic Living Skills (CEBLS) and the VILS to evaluate convergent validity and inter-rater reliability. The General Health Questionnaire (GHQ-12) was used to evaluate divergent validity. The assessments were repeated after a week to evaluate test-retest reliability.
RESULTS: The scale had good inter-rater reliability 0.938 (95% confidence interval [CI] 0.887-0.967) and test-retest reliability 0.907 (95% CI 0.865-0.937). The correlation between total score of VILS and CEBLS (Pearson's correlation coefficient [PCC] = 0.611; P = 0.001) suggested moderate convergent validity. The correlation between total score of VILS and GHQ-12 (PCC = -0.260; P = 0.105) implied good divergent validity.
CONCLUSION: Preliminary data suggest that the VILS is clinically useful for the Indian population. Copyright:

INTRODUCTION

Life skills, otherwise called as activities of daily living (ADLs), have been defined by the World Health Organization as abilities for adaptive positive behavior that enable us to deal effectively with the demands and the challenges of everyday life.[1] Life skills include basic ADL (BADLs), routine everyday activities like bathing, dressing, feeding, personal hygiene, grooming, and toilet hygiene. They also include instrumental ADL (IADLs), which are the more complex ADLs necessary for living in the community, including competence in skills such as shopping, cooking, and managing finances. They are essential for developing psychosocial, emotional, cognitive, behavioral, and resilience skills to negotiate everyday challenges and productive involvement in the community.[1] Impairments in adaptive life skills are a major source of disability in patients with chronic mental illnesses.[2] Interventions targeting optimal independent functioning have been found to be essential for re-integration of persons with mental illness.[3] Failure to focus on independent living skills is also thought to increase family burden and economic disadvantage.[4]

While assessing everyday performance, it is important to differentiate between what a person is able to do (functional capacity) and what he actually does (real-world performance), called as the competence/performance distinction.[56] Among the assessment methods available for measuring functional capacity, performance-based measures are more predictive of real-world outcomes than self-report instruments and direct observation of behavior.[7] The University of California San Diego Performance-Based Skills Assessment (UPSA) is a widely used scale, assessing performance in five domains of independent community living skills-household chores, communication, finance, transportation, and planning recreational activities.[8] However, since the tasks in a performance-based measure vary according to the cultural context, and since everyday self-care activities are also essential for independent living, there is a need to tailor these assessments to meet local standards. For example, the use of spoons, forks, and knife by other populations cannot be compared with rural Indian population as hands are preferred for eating. The materials, procedures, and cuisines related to meal preparation vary significantly even within India. The use of electrical appliances in home management tasks like iron box, food processor, washing machine, and dishwasher is not as prevalent in rural populations as compared to manual hand techniques.

Despite evidence supporting the importance of assessment and training in life skills for people with mental illness, research in this area has been minimal in India and is a need of the hour.[9] A recent meta-analysis also documents the lack of good evidence for the effectiveness of life skill programs and emphasizes the need for more robust studies.[10] The Vellore Inventory of Life Skills (VILS) was thus developed to address the dearth of a culturally relevant performance-based measure to assess the life skills of persons with severe mental illness in low- and middle-income countries (LMIC).

MATERIALS AND METHODS

Study setting

The study was conducted in the department of psychiatry of a 122-bedded tertiary referral center with an average daily footfall of around 500 outpatients. The treatment team consisting of psychiatrists, occupational therapists, psychiatric nurses, clinical psychologists, and psychiatric social workers employs a multidisciplinary approach in treating adults and children with mental and behavioral disorders. The center runs an inpatient occupational therapy program with a focus on improving various domains of life skills and occupational functioning. This inventory was developed specifically to aid in the assessment and thereafter goal setting for improving the life skills of inpatients undergoing the training program at the unit.

The study design and inventory construction was conceptualized by RS and KSJ, who aided by an expert committee of occupational therapists, reviewed current literature and provided input on items and scoring. It was found that there were no performance-based measures for daily living skills adapted for developing countries like India. Furthermore, most scales assessed either BADLs or IADLs, although developmentally, basic self-help skills act as precursors to advanced living skills, and both need to be essentially focused on in life skills training. Hence, focusing on a performance-based measure which assesses both BADLs and IADLs was thought to be more resource optimizing and reliable.

Construction of the inventory

Review of instruments

The contents, items, scoring, and interpretation of the following scales were reviewed during the search of literature: (1) Kohlman Evaluation of Living Skills,[11] (2) Life Skills Profile,[12] (3) Milwaukee Evaluation of Daily Living Skills,[13] (4) Lawton IADL Scale,[14] (5) Independent Living Skills Survey,[15] and (6) Comprehensive Evaluation of Basic Living Skills (CEBLS).[16]

Item collection and categorization

Each scale and their items were examined and the inventory was categorized into two domains, namely BADL and IADL, each with six components. Since the skills are multidimensional, the items were not distributed across a uniform scale but rather as an inventory of minimum skill levels achieved. Hence, each component was broken down into steps using task analysis and was hierarchically arranged into skills at either Basic, Intermediate, or Advanced level, keeping the self-help developmental milestones from childhood till adolescence as a reference. Thus, the final version of the VILS has six BADL components of (i) bathing, (ii) toilet hygiene, (iii) oral hygiene, (iv) dressing, (v) eating, (vi) grooming, and six IADL components of (i) financial management, (ii) food management, (iii) health management, (iv) community mobility (v) household management, and (vi) academic/vocational skills [Appendix 1].

Scoring

The scoring was prepared progressively from basic to advanced level, giving one score for each step that the person is able to perform at each level. For example, the component of bathing has four items each at the basic and intermediate level and three items at advanced level, adding up to a total possible score of 11. A person scoring from 1 to 4 will be considered to be at the basic level, 5 to 8 at the intermediate level, and 9 to 11 at the advanced level in bathing. Likewise, it would be possible to designate the current level of functioning of a person in each of the 12 components of the VILS. Subsequently, the goal of intervention would be to train the skills directly above the current functional level.

Study sample

The sample size calculation based on the guidelines for estimating sample size for intraclass correlation coefficient (ICC), for two observations, with a prespecified alpha value of 0.05, power of 0.9, and ICC value of 0.3 was 91.[17] Out of one hundred and ten consecutive inpatients recruited, ten assessments could not be completed due to unplanned discharge or emergence of psychotic symptoms; hence, data were collected till a sample size of 100 was reached. Patients with a diagnosis of schizophrenia or bipolar affective disorder attending the inpatient occupational therapy program at the department of psychiatry aged between 18 and 60 years of age and who gave written informed consent were included for the study. Clients with a clinical diagnosis of moderate to profound intellectual disability, those with organic mental disorders, and those with acute psychotic presentations were excluded from the study.

Assessment tools used

CEBLS:[16] This is a measure with seven domains of basic living skills, (i) meal planning (ii) telephone (iii) bus (iv) shopping (v) meal preparation (vi) serving and eating and (vii) meal cleanup. Each component is marked on a scale of 1–4 where 1 is “can't perform,” 2 is “requires much assistance,” 3 is “requires some assistance,” and 4 is “performs independently and correctly.” It has a maximum possible score of 232 across 58 items. This scale was chosen to evaluate convergent validity as the scale had domains similar to the IADL domains of VILS and was also the only one to include few BADL components also

The General Health Questionnaire (GHQ):[18] This is a measure of current mental health originally developed as a 60-item instrument; for the current study, the 12-item GHQ-12 was used. The GHQ-0011 scoring method was used, which yields a maximum possible score of 12. The GHQ-12 was used to evaluate divergent validity as the construct of psychological well-being is sufficiently dissimilar to that of independent living skills

Brief Psychiatric Rating Scale (BPRS):[19] The BPRS assesses psychiatric symptoms and consists of 18 items with scores ranging from 1 (not present) to 7 (extremely severe) and 0 for not assessed, with a maximum possible score of 126. The BPRS scores, which are routinely rated by the primary treating psychiatrist, were documented

VILS: The final version of the inventory has 12 domains, six each under BADLs and IADLs.

Procedure

The details of the study were explained to all participants, and written informed consent was obtained. The VILS was scored by two investigators (MCC and FS) independently and simultaneously for evaluating inter-rater reliability. The BADL items were scored during direct observation of performance in the patient's residential area. For the items of bathing and toilet hygiene, to respect patient privacy, investigators only observed preparations made for the activity and information was supplemented from caregiver report. The IADL items of food management, health management, and household management were also scored with direct observation in the patient's residential area. The items of community mobility and financial management were scored while taking the patient out to nearby shops/bank/ATM kiosk, accompanied by the caregiver. The component of academic/vocational skills was simulated in the therapy setting. The assessments were timed to coincide with the usual time patients routinely performed the ADLs and thus were not completed at a stretch. Overall, each assessment took around an hour to complete. A third investigator (RS) scored the participants on the CEBLS and GHQ-12 for evaluating convergent and divergent validity. The VILS was scored again by one investigator (MCC) after a week to evaluate test–retest reliability.

Data analysis

Summary statistics, mean and standard deviation, frequencies, and percentages were used for reporting demographic and clinical characteristics. The correlation of VILS with the CEBLS, BPRS, GHQ-12, and continuous sociodemographic variables was evaluated using the Pearson's correlation coefficient (PCC). Differences were considered significant at P < 0.05. The association between categorical sociodemographic variables and the VILS was measured using one-way ANOVA test. The initial assessment score of VILS administered by MCC was used for the correlation and association tests. Inter-rater and test–retest reliabilities were evaluated using the ICC with a 95% confidence interval (CI). All the statistical analyses were performed using SPSS 18.0 (SPSS Inc., Chicago, Ill., USA).

RESULTS

One hundred participants were recruited for the study. The majority of the participants were male, young adults, single, with undergraduate education, middle socioeconomic status, and currently employed. The sociodemographic characteristics of the sample are shown in Table 1.

Table 1

Demographic characteristics of the study population (n=100)

Characteristic	Mean (SD) frequency (%)
Age	34.22 (10.67)
Illness duration	7.66 (5.77)
Sex
Male	69 (69)
Female	31 (31)
Diagnosis
Schizophrenia	75 (75)
BPAD	25 (25)
Marital status
Married	41 (41)
Unmarried	59 (59)
Socioeconomic status
Low	20 (20)
Middle	58 (58)
High	22 (22)
Education
Secondary	24 (24)
Higher secondary	19 (19)
Undergraduate	44 (44)
Postgraduate	13 (13)
Employment status
Employed	42 (42)
Unemployed	20 (20)
Student	16 (16)
Never employed	14 (14)
Homemaker	8 (8)
Occupation (n=42)
Elementary occupation	14 (33.3)
Skilled/sales workers	9 (21.4)
Plant and machine	6 (14.3)
Craft and trade workers	6 (14.3)
Technicians	5 (11.9)
Clerks	1 (2.4)
Professionals	1 (2.4)

SD – Standard deviation; BPAD – Bipolar affective disorder

Validity

The CEBLS was used to measure convergent validity. The correlation between the total scores on the two scales was moderate (PCC = 0.611; P = 0.001), suggesting that these scales seem to assess similar constructs. The GHQ-12 scores, which is a measure of overall mental health, when correlated with the VILS, provided low correlation (PCC = −0.260; P = 0.105), suggesting divergent validity. The details of the correlations are shown in Table 2.

Table 2

Correlation of Vellore Inventory of Life Skills with other scales

Characteristic	Mean (SD)	PCC (P)
CEBLS total score	152.05 (34.67)	0.611 (0.001)
BPRS total score	36.62 (11.23)	−0.175 (0.321)
GHQ 12 total score	6.86 (2.79)	−0.260 (0.105)

CEBLS – Comprehensive evaluation of basic living skills; GHQ – General health questionnaire; BPRS – Brief psychiatric rating scale; PCC – Pearson’s correlation coefficient; SD – Standard deviation

Reliability

The test–retest and inter-rater reliability scores of all domains of the VILS have been documented in Table 3. Most individual domains of VILS as well as the total score recorded good inter-rater reliability; the domains of 'eating' and 'grooming' had moderate levels of reliability. Most individual domains of VILS as well as the total score also recorded good test-retest reliability; the domains of “bathing,” “oral hygiene,” “dressing,” “eating,” and “grooming” had moderate levels of reliability.

Table 3

Reliability data for all domains of Vellore Inventory of Life Skills

Domain	Inter–rater reliability ICC (95% CI)	Test–retest reliability ICC (95% CI)
VILS – Bathing	0.815 (0.676–0.897)	0.641 (0.509–0.743)
VILS – Toilet hygiene	0.894 (0.809–0.943)	0.815 (0.737–0.872)
VILS – Oral hygiene	0.848 (0.731–0.917)	0.603 (0.462–0.714)
VILS – Dressing	0.846 (0.727–0.915)	0.560 (0.409–0.681)
VILS – Eating	0.663 (0.446–0.807)	0.487 (0.322–0.623)
VILS – Grooming	0.630 (0.399–0.785)	0.542 (0.388–0.667)
VILS – Financial management	0.922 (0.857–0.958)	0.923 (0.888–0.948)
VILS – Food management	0.924 (0.861–0.959)	0.916 (0.877–0.942)
VILS – Health management and maintenance	0.946 (0.900–0.971)	0.911 (0.871–0.939)
VILS – Community mobility	0.973 (0.949–0.986)	0.908 (0.866–0.937)
VILS – Household management	0.888 (0.798–0.939)	0.875 (0.820–0.914)
VILS – Academic/vocational skills	0.919 (0.851–0.956)	0.959 (0.939–0.972)
VILS – Total	0.938 (0.887–0.967)	0.907 (0.865–0.937)

VILS – Vellore Inventory of Life Skills; ICC – Intraclass correlation coefficient; CI – Confidence interval

Extent of life skills deficit

In terms of BADLs, most of the study population was at the advanced level, with only one person at the basic level. However, in the domain of IADLs, most of the population was at the intermediate level, with more than half of them being at a basic level in the domain of “household management.” The details regarding the extent of life skills deficit can be found in Table 4.

Table 4

Description of Vellore Inventory of Life Skills score among the study population (n=100)

Characteristic	Mean (SD) frequency (%)
VILS total score	99.86 (17.13)
VILS – Bathing
Intermediate	32 (32)
Advanced	68 (68)
VILS – Toilet hygiene
Intermediate	14 (14)
Advanced	86 (86)
VILS – Oral hygiene
Intermediate	4 (4)
Advanced	96 (96)
VILS – Dressing
Intermediate	12 (12)
Advanced	88 (88)
VILS – Eating
Intermediate	4 (4)
Advanced	96 (96)
VILS – Grooming
Basic	1 (1)
Intermediate	18 (18)
Advanced	81 (81)
VILS – Financial management
Basic	25 (25)
Intermediate	69 (69)
Advanced	6 (6)
VILS – Food management
Basic	25 (25)
Intermediate	60 (60)
Advanced	15 (15)
VILS – Health management and maintenance
Basic	6 (6)
Intermediate	83 (83)
Advanced	11 (11)
VILS – Community mobility
Basic	11 (11)
Intermediate	65 (65)
Advanced	24 (24)
VILS – Household management
Basic	51 (51)
Intermediate	41 (41)
Advanced	8 (8)
VILS – Academic/vocational skills
Basic	41 (41)
Intermediate	56 (56)
Advanced	3 (3)

VILS – Vellore Inventory of Life Skills; SD – Standard deviation

Correlation between psychopathology and life skills

The correlation between the total score of VILS and BPRS was not statistically significant (PCC = −0.175; P = 0.321). Domain wise correlation of the VILS with the BPRS scores also failed to yield statistically significant results. The details regarding the BPRS scores are shown in Table 2.

Comparison between sociodemographic factors and domains of life skills

The group means differences for “educational status” was statistically significant for BADL domains of “bathing” (F = 4.882; P = 0.003), “toilet hygiene” (F = 4.742; P = 0.004), “dressing” (F = 2.995; P = 0.036), “eating” (F = 2.848; P = 0.042) and for almost all IADL domains of “financial management” (F = 10.252; P = 0.001), “food management” (F = 7.006; P = 0.001), “health management” (F = 6.669; P = 0.001), “household management” (F = 4.665; P = 0.004), and “academic/vocational skills” (F = 7.213; P = 0.001). The group mean differences for “community mobility” neared significance (F = 2.646; P = 0.053) and the total VILS score was also statistically significant (F = 9.354; P = 0.001) between the groups. There were statistically significant differences between group means for diagnosis and the IADL domains of “financial management” (F = 4.273; P = 0.041), “community mobility” (F = 9.914; P = 0.002), and “health management” (F = 4.047; P = 0.047). There were also statistically significant differences between group means of employment status and the domains of “eating” (F = 4.046; P = 0.005), “financial management” (F = 3.836; P = 0.006), “community mobility” (F = 3.121; P = 0.019), “academic/vocational skills” (F = 2.661; P = 0.037) as well as the total VILS score (F = 2.715; P = 0.034). In comparing group means of various types of occupation among the employed participants, there were statistically significant differences in the IADL domains of “financial management” (F = 2.924; P = 0.020), “health management” (F = 2.455; P = 0.044), “'academic/vocational skills” (F = 2.743; P = 0.027), and the total VILS score (F = 2.821; P = 0.024). With respect to group mean differences in socioeconomic status, the IADL domains of “health management” (F = 3.381; P = 0.038), “community mobility” (F = 4.037; P = 0.021), and “academic/vocational skills” (F = 6.208; P = 0.003) were statistically significant. The IADL domains of “food management” (F = 5.876; P = 0.017) and “household management” (F = 8.200; P = 0.005) had statistically significant differences in group means when compared with gender.

When correlated with duration of illness, there were statistically significant results in the IADL domains of “financial management” (PCC = −0.206; P = 0.040) and “community mobility” (PCC = −0.200; P = 0.046) but not in the total score of VILS. Other than the BADL domain of “eating” (PCC = −0.239; P = 0.017), there was no statistically significant correlation between the various domains of VILS and age of participants. There was no statistically significant difference between group means when the VILS domains were compared with the marital status of the participants.

DISCUSSION

The VILS had only moderate correlation with the CEBLS scores; this could be because the CEBLS assesses only seven domains, one in BADL and six in IADL, as opposed to six BADL and IADL domains each of the VILS. Since the VILS was specifically formulated to comprise of domains not included in other assessments, this can be considered acceptable. The test–retest reliability of most of the BADL domains was lower than that of the IADL domains. The reason for the lower levels of reliability scores could be that the assessments were spaced a week apart; however, training on BADLs is initiated immediately after admission to the setting. The change in scores could be attributed to improvement in skills as a result of intervention. The BADL performance among the population was better than the IADL performance, which can be representative of the increased complexity of IADLs as compared to the BADL skills. The lack of correlation between the VILS and BPRS scores can imply that life skills dysfunction can be present irrespective of the severity of illness; this finding is similar to a previous study done at the same center.[3]

Many IADL domains also seem to have significant group differences when compared with sociodemographic variables of educational status, employment status, type of occupation, socioeconomic status, and gender. Longitudinal follow-up studies and interventional studies are warranted to understand the directionality of these associations.

The VILS addresses two pertinent issues related to the assessment of life skills in LMIC. The direct, performance-based nature of assessment yields more reliable results than self- or proxy-rated checklists. The combining of BADLs and IADLs in one assessment ensures ease of goal setting and seamless progression in life skills training. Although the assessment is time consuming and can only be done in a residential/home setting; considering that the purpose of any functional training is the generalization of skills to real-life performance, assessing skills in such settings is justified. Since most of the assessment utilizes direct observation in the residential area, the person-specific context of skill performance is retained, thus making it feasible to be used across varying social and cultural backgrounds.

Limitations

The VILS is not feasible to be used in outpatient settings and its exhaustive nature precludes completion of the entire assessment at one stretch. It is also necessary to have key informants present during the assessment to complement the information given, which can be cumbersome in some healthcare settings. Since the VILS was developed with the aim of measuring progress in life skills as a result of intervention, longitudinal studies of repeated assessments will also have to be conducted. Recommendations for future would include evaluating the predictive validity of the VILS for employment/independent living and validation in the adolescent age group when life skills are developing.

CONCLUSION

The VILS was developed to aid in baseline assessment and subsequent documentation of progress in facilities providing life skills training for persons with severe mental illness. Preliminary data suggest that VILS seems to meet this requirement. The findings would need to be reinforced with longitudinal data to evaluate change over time.

Financial support and sponsorship

This study was approved and funded by the Institutional Review and Ethics Board, Christian Medical College, Vellore (IRB Min. No. 11585). The funding source had no further involvement in the conduct of the research or preparation of the article.

Conflicts of interest

There are no conflicts of interest.

Items

	Basic activities of daily living	Basic	Intermediate	Advanced
1	Bathing
2	Toilet hygiene
3	Oral hygiene
4	Dressing
5	Eating
6	Grooming
	Instrumental activities of daily living
7	Financial management
8	Food management
9	Health management
10	Community mobility
11	Household management
12	Academic/vocational skills