The Effect of a Reminder Short Message Service on the Uptake of Glaucoma Screening by First-Degree Relatives of Glaucoma Patients: A Randomized Controlled Trial.

PURPOSE: The purpose of this study was to determine the role of a reminder short message service (SMS) on the uptake of glaucoma screening by first-degree relatives (FDRs) of patients with primary open-angle glaucoma (POAG) in North-central Nigeria following a telephone invitation for screening.
MATERIALS AND METHODS: A randomized controlled trial was conducted in the eye clinic of a tertiary hospital in Jos, North-central Nigeria. Two hundred FDRs of patients with POAG were invited through phone for free glaucoma screening and randomly allocated into two groups. The intervention group received a reminder SMS, whereas the control group did not receive a reminder. Those who failed to turn up for screening were contacted through phone to determine the reasons for their nonattendance. Chi-square test and bivariate analysis were used to compare attendance rate between the two groups.
RESULTS: Sending a reminder SMS following a telephone invitation had no effect on the uptake of glaucoma screening. The response rate was lower in the phone call plus reminder SMS group (43.0% vs. 53.0%) though the difference was not statistically significant (P = 0.157). Competing needs such as work and lack of transport fare were the most common reasons given for not attending the screening.
CONCLUSION: A reminder text message is not an effective tool for increasing the uptake of glaucoma screening in at-risk individuals in North-central Nigeria. Existing barriers to health care in the country need to be addressed before mobile phone technology can be effectively used in increasing the utilization of any free eye screening service. Copyright:

RCT Entities:   Population Interventions Outcomes

Introduction

Glaucoma has been ranked as the second leading cause of blindness globally after cataract with increasing significance, due to an increasing aging population.[1] It poses a greater health challenge than cataract as it leads to irreversible blindness.[1] As of 2013, about 64.3 million people were estimated to be affected with the disease, with the burden projected to increase to about 76.0 million in 2020 and 111.8 million by 2040.[2] The Nigerian National Blindness and Visual Impairment Survey placed the prevalence of blindness from primary open-angle glaucoma (POAG) among individuals 40 years and above in Nigeria at 5.02%.[3]

Risk factors for the disease include rise in intraocular pressure (IOP), increase in age, black race, first-degree relative (FDR) with POAG, and vascular disease.[4] Compared to the general population, relatives of patients with POAG have a 2.9-fold increased tendency to develop the disease.[5] Diagnostic tools for early detection of the disease are readily available in developed nations, unlike in developing countries, and furthermore they are expensive where they exist.[6] Mass screening for glaucoma is expensive and thus, not cost-effective due to the nonavailability of a reliable, affordable, and readily available test.[6] The current practice restricts screening to high-risk groups, such as older individuals, those with a history of POAG in a close family member over the age of 40, and people of black ethnicity.[7] Early detection strategies suitable for resource-lean environments such as ours may aid in identifying some of these high-risk individuals and prevent blindness from the disease.

The mobile phone short message service (SMS) has been successfully used in medical practice to improve clinic attendance in various specialties including ophthalmology, and also to improve compliance with treatment in glaucoma and pediatric cataract.[8910111213] Reminder text messages have also been used with success in increasing the uptake of cancer screening services.[1415] They have been found to be as effective as telephone reminders in improving clinic attendance rates.[16] Text messaging reminder system, however, has the advantage of being convenient, inexpensive, and able to reach the intended person immediately.[17] It is also believed to be more practical and well suited to different settings.[8] Its use as a means to remind FDRs of patients with glaucoma about their screening appointments may be a cost-effective strategy that will aid in the early detection of the disease. This study was, therefore, designed with the primary aim of assessing the role of mobile SMS reminders on the uptake of glaucoma screening by FDRs of patients with POAG in North-central Nigeria. The secondary aim was to determine the response rate of this group of individuals to a free glaucoma screening initiative.

Materials and Methods

This is a randomized controlled trial involving FDRs of patients with POAG seen at the eye clinic of a tertiary hospital in Jos, North-central Nigeria. Ethical approval was obtained from the ethical review committee of the hospital. A written informed consent was obtained from all the study participants before enrollment in the study and the tenets of the Helsinki Declaration were adhered to. All consenting newly diagnosed and old patients with POAG seen at the eye clinic within the study period and their FDRs were included in the study. Exclusion criteria included index patients <18 years of age, index patients with glaucoma other than POAG, FDRs <30 years of age, accompanying FDRs, and FDRs without a functional phone or active phone line. For the purpose of this study, a FDR was considered as a parent, sibling, or offspring of a glaucoma patient aged ≥30 years.[5] A diagnosis of glaucoma was made using the International Society of Geographical and Epidemiological Ophthalmology classification, while a glaucoma suspect was defined as an individual with any of the following: IOP ≥21 mmHg, a vertical cup–disc ratio (VCDR) ≥0.7, or a difference in VCDR between the two eyes of >0.2.[45] A sample size of 200 was calculated for the study with 100 persons in each group using the Fisher's formula[18] assuming a 95% confidence interval (z = 1.96) with precision level set at 10%, setting a prevalence of uptake of 13.43% obtained from a similar study in Cameroon,[19] and assuming a nonresponse rate of 10%. Patients with POAG presenting to the clinic were first allocated a study number and were administered a questionnaire. Information obtained included patients’ bio data and information on the patients’ clinical condition such as how long the patient had been diagnosed with glaucoma, where the diagnosis was made, and treatment the patient was on. Information on the FDR including name, age, sex, relationship to patient, residential address, and telephone number was also obtained. A phone call was then made by the index patient to his/her FDR(s) using the first author's phone. The index patient first spoke to the FDR and identified himself/herself. The first author was then introduced by the index patient to the FDR, after which she passed across the following information: your relative is being treated for an eye disease called glaucoma, the disease can go unnoticed until blindness ensues, blindness from the disease is irreversible, being a relative of someone with the disease puts one at risk of developing glaucoma, early detection and treatment can help prevent blindness from the disease, and kindly come to the eye clinic at the teaching hospital within 2 weeks from today, Monday to Friday between 9 a.m. and 1 p.m. for a free eye examination. The FDR was asked to call the first author on arrival at the clinic and was informed that he/she will be exempted from the normal hospital protocol such as card registration and payment of consultation fees.

The index patient was then presented with a box with folded small pieces of paper numbered 1–200 and asked to pick a piece of paper for each recruited FDR. The first number picked by the first index patient was an odd number. A coin was then tossed to determine which group this patient would belong, with heads representing the control group (phone call alone) and tail the intervention group (phone call + SMS). The person who tossed the coin was blinded to the study and the outcome of the coin toss was heads. This first FDR therefore fell into the control group and all subsequent FDRs whose index patients picked an odd number for them fell into the control group and did not receive a reminder SMS. The FDRs with even numbers picked for them by the index patients fell into the test arm and received a reminder SMS. Those FDRs who did not pick the call at the point of recruitment after two attempts were excluded from the study. For FDRs who fell into the intervention group, a reminder SMS was sent to them on the 1st day of the week following the phone call invitation. The content of the SMS was “this is a reminder of your appointment for free glaucoma screening at the teaching hospital eye clinic between 9 a.m. and 1 p.m. from Monday to Friday within the next 1 week.” At presentation, the FDRs had their phone numbers confirmed and were given a study number and matched with the study number of the index patient through whom they were invited. A questionnaire was then administered and the following information was obtained: demographic data and details of relevant ocular history including if the participant had had an eye examination in the past. Ocular problems in the past as well as at the time of study were noted and family history of blindness was documented. The FDR then had a detailed ocular examination which included visual acuity and refraction, slit-lamp biomicroscopy of the anterior segment, applanation tonometry, standard full-threshold automated static perimetry, gonioscopy, and a dilated fundus examination with a 78 D lens. Any interventional measures the participants received were also documented. At the end of the 2-week screening period given for the last recruited FDR, an additional 1 month was allowed to accommodate possible late presenters.

All participants diagnosed with POAG or were identified as glaucoma suspects were advised to register in the eye clinic for treatment and follow-up. Phone calls were subsequently made by the first author to those who did not show up for screening to determine the reasons for their failure to turn up. Not more than two attempts were made 4 h apart between the hours of 9 a.m. and 6 p.m. Figure 1 depicts the study flowchart.

Figure 1

Study flowchart

Collected data were entered into Microsoft Excel spreadsheets and analyzed with Statistical Package for the Social Sciences (SPSS) software version 20 (IBM Corporation, Chicago, Illinois, USA). Frequencies, means, and standard deviations were determined. All tests conducted were two sided, and the confidence intervals were estimated at the 95% level. Bivariate analysis was conducted using cross tabulations. Pearson's Chi-square test and Fisher's exact test (where the expected frequency of a cell was <5) were conducted and significance was placed at P < 0.05. Quantitative variables were expressed as means and standard deviation.

Results

Fifty-nine index POAG patients were recruited over a period of 5 weeks (about 12 patients recruited per week). These were made up of 38 males and 21 females, giving a male: female ratio of 1.8:1. The mean age of the index patients was 56.0 ± 15.3 years (40.0–71.0 years). Each index patient gave a range of 1–5 FDRs until 200 FDRs were recruited. These comprised of 117 (58.5%) males and 83 (41.5%) females, giving a male: female ratio of 1.4:1. A minimum of eight and a maximum of 16 index patients were recruited per week. The mean number of FDRs recruited per index patient was 3 ± 1. Only 96 recruited FDRs, however, presented for screening, giving a response rate of 48% [Table 1]. These were made up of 47 (49.0%) males and 49 (51.0%) females. Forty-three (43.0%) of these participants received a reminder SMS, while 53 (53.0%) were in the control group. This difference was not statistically significant (P = 0.15). Only four FDRs (4.2%) presented after the given period for their screening had elapsed and were analyzed under those who presented for screening. The mean age of the FDRs who presented was 37.8 ± 6.9 years (range: 33.0–40.0 years) and most were females, 49 (51.0%). There was no statistically significant difference between the age and sex distribution of FDRs who presented for screening as shown in Table 2. The demographic characteristics of those who presented for screening are shown in Table 3.

Table 1

Response of first-degree relatives to invitation for screening

	Phone call only, n (%)	Phone call+SMS, n (%)	Total, n (%)
FDR did not present	47 (47.0)	57 (57.0)	104 (52.0)
FDR presented	53 (53.0)	43 (43.0)	96 (48.0)
Total	100 (100)	100 (100)	200 (100)

χ²=2.003; P=0.157. FDR: First-degree relative, SMS: Short message service

Table 2

Age and sex distribution of first-degree relatives that presented for screening

Age (years)	Phone call+SMS group		Phone call-only group		Total
	Female, n (%)	Male, n (%)	Female, n (%)	Male, n (%)
30–34	8 (34.8)	8 (40.0)	6 (23.1)	7 (25.9)	29 (30.2)
35–39	9 (39.1)	7 (35.0)	14 (53.9)	12 (44.4)	42 (43.8)
40–44	4 (17.4)	1 (5.0)	3 (11.5)	5 (18.6)	13 (13.5)
45–49	0	2 (10.0)	2 (7.7)	3 (11.1)	7 (7.3)
≥50	2 (8.7)	2 (10.0)	1 (3.8)	0 (0.0)	5 (5.2)
Total	23 (100)	20 (100)	26 (100)	27 (100)	96 (100)
χ² (P)	3.504 (0.651*)		1.959 (0.767*)

*Fisher’s exact derived P. SMS: Short message service

Table 3

Demographic data of first-degree relatives who presented for screening

Variable	Phone call only, n (%)	Phone call+SMS, n (%)	Total, n (%)	χ²	P
Sex
Female	26 (49.1)	23 (53.5)	49 (51.0)	0.187	0.687
Male	27 (50.9)	20 (46.5)	47 (49.0)
Total	53 (100)	43 (100)	96 (100)
Address
Rural	1 (1.9)	11 (25.6)	12 (12.5)	14.586	0.001*
Semi urban	2 (3.8)	4 (9.3)	6 (6.3)
Urban	50 (94.3)	28 (65.1)	78 (81.2)
Total	53 (100)	43 (100)	96 (100)
Education
None	0 (0.0)	1 (2.3)	1 (1.0)	8.06	0.031*
Primary	3 (5.6)	4 (9.3)	7 (7.3)
Secondary	32 (60.4)	14 (32.6)	46 (47.9)
Tertiary	18 (34.0)	24 (55.8)	42 (43.8)
Total	53 (100)	43 (100)	96 (100)
Occupation
Business	28 (52.8)	10 (23.2)	38 (39.6)	20.565	0.001*
Civil service	12 (22.6)	15 (34.9)	27 (28.1)
Student	9 (17.0)	7 (16.3)	16 (16.7)
Farmer	0 (0.0)	8 (18.6)	8 (8.3)
Homemaker	1 (1.9)	3 (7.0)	4 (4.2)
Unemployed	3 (5.7)	0 (0.0)	3 (3.1)
Total	53 (100.0)	43 (100.0)	96 (100.0)

*Fisher’s exact derived P. SMS: Short message service

Most FDRs, 59 (61.5%), had normal eyes. Ten (10.4%) FDRs were diagnosed with POAG with a mean age of 38.4 years (range: 30.0–50.0 years), whereas six (6.2%) were identified as glaucoma suspects. All the 104 recruited participants who did not present for screening were contacted via phone call, of which six (5.8%) did not pick the call. Majority, 26 (25%), of those who did not come for screening stated “competing needs, e.g., work” as their reason [Table 4]. Most people, 18 (31.6%), who gave this as their reason had received a reminder SMS. Lack of money was the second most common reason and this was given by 17 (16.3%) respondents. All nine people who said they failed to turn up because they forgot did not receive the reminder SMS. All those in the intervention group confirmed that they received the SMS reminder.

Table 4

Reasons for nonattendance

Reason for nonattendance	Phone call only, n (%)	Phone call+SMS, n (%)	Total, n (%)
Competing needs, for example, work	8 (17)	18 (31.6)	26 (25.0)
Lack of transport money	4 (8.5)	13 (22.8)	17 (16.3)
Hospital too far	5 (10.6)	6 (10.5)	11 (10.6)
Time constraints	5 (10.6)	6 (10.5)	11 (10.6)
Forgot	9 (19.2)	0 (0.0)	9 (8.7)
Fear of diagnosis	2 (4.3)	7 (12.3)	9 (8.7)
Need not felt	4 (8.5)	4 (7.0)	8 (7.7)
Did not pick	4 (8.5)	2 (3.5)	6 (5.7)
Examined elsewhere	4 (8.5)	2 (3.5)	6 (5.7)
Notice too short	1 (2.2)	1 (1.8)	2 (1.9)
Total	47 (100)	57 (100)	104 (100)

SMS: Short message service

Discussion

Our study revealed that sending a reminder SMS following a telephone invitation did not increase the uptake of glaucoma screening as majority of those who presented for screening were in the control group. This is contrary to the findings from previous studies which demonstrated its effectiveness in increasing the uptake of cancer screening programs.[1415] Kerrison et al. in a study conducted in London showed that sending women a text message reminder before their first routine breast screening appointment significantly increased attendance.[14] Wanyoro et al. in Kenya also observed that women who received SMS reminders were eight times more likely to adhere to scheduled rescreening for cervical cancer than those who did not receive reminders.[15] The authors recommended that SMS reminders should be integrated into the cervical cancer screening programs where other means of reminders are not available.[15] We did not come across any other study in the literature that examined the role of a reminder SMS in glaucoma screening. Several studies have also overwhelmingly demonstrated the effectiveness of SMS reminders in lowering clinic nonattendance rates.[891011] A small number of studies, however, reported no significant change in the clinic nonattendance rate from an SMS intervention.[20212223] In a study among people living with HIV in Haiti, sending an SMS reminder had no significant impact on clinic attendance rates. The authors suggested that probably the phone itself, its use (in particular, the use of the SMS function), or reading the SMS was the reason for this.[20] In a randomized controlled study on texting appointment reminders to repeated nonattenders in primary care in Scotland, the authors observed that even though a reminder SMS showed promise, it did not result in a significant reduction in nonattendance rates.[21] In agreement with our finding, another study among patients with HIV in North Carolina found that nonattendance was slightly higher in patients that received a reminder SMS.[22]

The overall response rate in the present study (48%) is higher than findings from similar studies in Tanzania (8.1%) and India (7%).[2425] Differences in methods of invitation of the FDRs for screening may account for this difference. Invitation of FDRs was by letters in the study by Rajendrababu et al., with 15% of the mails being returned owing to incorrect mailing address.[25] A phone call or SMS has the advantage of being able to reach the intended person immediately. However, in contrast to our finding, another study in the United Kingdom (UK) that invited siblings of glaucoma patients for screening by an explanatory letter reported a very high response rate of 90%.[26] Barriers to accessing eye care, some of which are peculiar to a developing country like ours, would explain this disparity. In addition, industrialized countries have higher levels of glaucoma awareness and more established eye care systems compared to developing countries.[27] Competing needs, lack of transport fare, hospital being too far, and time constraints were the major reasons given by those who failed to attend the screening in this current report. In the study by Vernon in the UK, only siblings of glaucoma patients residing within 15 mile radius of the hospital where the screening was conducted were invited for the study.[26] Reducing travel distance and travel time will increase the uptake of a screening service. Barriers to accessing health care were also identified as the reason for the poor response rate in the study by Munachonga et al. in Tanzania.[24] The authors observed that providing good-quality counseling of index cases and offering glaucoma examination free of charge were not sufficient to reach those at risk of glaucoma, and that indirect costs of accessing services were significant barriers to utilization of the service.[24] Rajendrababu et al. suggested a lack of knowledge about the hereditary nature of glaucomas as a reason for the poor response rate reported in their study.[25] In the current study, all those who said they did not turn up for the screening because they forgot (19.2%) did not receive a reminder SMS. This proportion would, however, not have made any significant difference had they received the reminder SMS and turned up for screening. We do not think a reminder phone call would have made any difference either in our study cohort.

Only a small proportion (6%) of FDRs in this study had undergone a previous glaucoma screening. This may be due to a lack of awareness about the presence of the disease in the family, the hereditary nature of the disease, as well as a lack of knowledge of the irreversible effect of the disease on the sight without treatment. Knowledge and awareness of glaucoma are generally poor in Africa.[2829] A study among FDRs of glaucoma patients in the southern part of the country, in agreement with our finding, reported only 7% as having gone for an eye examination prior to the study.[29] Another study in Brazil, however, in contrast to our finding, reported 44% of FDRs as having had their eye pressure checked in the past.[30]

This study had some limitations. First of all are the limitations associated with self-reported data such as response bias, social desirability bias, and response-shift bias.[31] Second, the status of a FDR was determined by the index patients. There may, therefore, have been some degree of bias as to who benefitted from the free eye examination and who did not.

Conclusion

A reminder SMS was not an effective tool for increasing the uptake of glaucoma screening service by at-risk individuals in our environment. Existing barriers to accessing health care must be addressed before mobile phone technology can be effectively used in increasing the utilization of such screening services.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.