Systematic review on barriers and enablers for access to diabetic retinopathy screening services in different income settings

Authors: Piyasena MM, Murthy GV, Yip JL, Gilbert C, Zuurmond M, Peto T, et al.

Geographical coverage: Asia, Africa, Australia, Europe, Middle East and North America

Sector: Service delivery

Sub-sector: Access, diabetic retinopathy screening (DRS), enablers/barriers to access

Equity focus: None specified

Study population: People with diabetes mellitus or providers and/or consumers of diabetic retinopathy screening

Review type: Other review

Quantitative synthesis method: Not applicable

Qualitative synthesis method: Narrative/thematic synthesis

Background:

Countries at different income levels have different enablers/barriers to successful diabetic retinopathy (DR) screening programmes. It is especially important to understand what these are in low income settings where there is rising prevalence of DR – knowing the barriers will contribute to more successful screening programmes.

Objectives:

To identify and contrast the barriers/enablers to diabetic retinopathy screening (DRS) for different contexts using both consumers, that is, people with diabetes mellitus (PwDM), and provider perspectives and system level factors in different country income settings.

Main findings:

The search identified 16,388 records, of which 77 studies were included in this review. Of the included studies, 59 (76.6%) were cross-sectional observational studies (33 observational, eight retrospective, one postal survey, two telephone interviews, one mixed method audit, and 14 population-based studies). Other study designs were three controlled trials(3.9%), one case control study (1.3%), four cohort studies (5.2%) and eight qualitative studies (10.4%), and two reviews (2.6%). The methodological quality of the included studies was reported by criteria only (the overall quality of each study was not reported), as the applicability to the review question was the main concern in the synthesis for the authors rather than the overall quality of a study. Three of the included studies were conducted in low income countries (LICs) (Tanzania and Nepal), 11 from low and middle income countries (LMICs) (Indonesia, India, Yemen, Kenya, Myanmar, Nigeria and Bangladesh), seven from upper middle income countries (UMICs) (Turkey, Iran, Mediterranean and China) and 56 from high income countries (HICs) (United Kingdom, United States, Germany, France, Ireland, Singapore, Canada, Oman, Hong Kong, South Korea, Australia, Taiwan, Italy and the Netherlands).

Thematic focus was to identify enablers/barriers to screening access based on income setting, looking at both consumer and providers of DR screening.

The barriers to DRS were identified based on the number of times a theme appeared, irrespective of the country income level. At consumer level, financial circumstances were the most reported barrier (reported in 31 of 77 studies, 40%), followed by the lack of knowledge about DR (reported in 19 of 77 studies, 25%), low educational attainment and poor literacy (reported in 16 studies, 21%), asymptomatic nature of DR (reported in 16 studies, 21%), the lack of awareness (reported in 15 studies, 20%), and time and priority issues (12/77, 16%). At the provider level, accessibility issues related with appointments were the most reported barrier (reported in 23 of 77 studies, 30%), followed by deficiencies in educating the users (reported in 21 studies, 27%), lack of knowledge and awareness among the providers (reported in 11 studies, 14%), lack of screening infrastructure (reported in 11 studies, 14%), cost of services (reported in 11 studies, 14%), and lack of human resources (reported in 10 studies, 13%).

Overall, awareness, knowledge and attitude of PwDM, and availability of skilled human resources and infrastructure (such as providers) emerged as the major barriers to access to DRS in any income setting. However, in low income settings specifically, lack of knowledge on DM eye complications, lack of awareness about importance of eye examination and lack of knowledge about availability of eye clinics were the main barriers for consumers.

Based on the findings of this review, the authors suggested that assessments of enablers/barriers should be carried out in each context before the implementation of a DR screening programme, and that consumer-based health educational interventions and provider-based skills interventions and infrastructure development would improve the access to DR screening programmes, especially in LICs.

Methodology:

The search was conducted in Medline, EMBASE and CENTRAL from inception to 15 December 2018. There were no limitations on date, language or study design, however, non-English studies were not ultimately included in the analysis.

Studies were included if they assessed barriers and facilitators to access DRS and discussed factors affecting the uptake of DRS services. Some studies only included patients, some only providers, some both. Consumers were PwDM or those who had been referred for DRS. Service providers included permanent health care institution and/or clinical decision makers and/or stakeholders involved in DRS decision-making. Studies included had to assess the barriers at group or individual level to PwDM accessing DR screening. Types of studies included were cross sectional, observational, case control study, cohort studies, qualitative studies and reviews.

The outcome of interest was “access” to DR screening, including all level of factors affecting the processes of screening in a health care facility.

Two reviewers independently screened the articles at title and abstract, and full-text screening levels for eligibility of inclusion. The data was extracted by two reviewers independently and cross-checked by a third reviewer.

Appraisal of skills programme tools for case-control, qualitative, cohort and randomised controlled studies were used to assess study quality and risk of bias, while observational cohort and cross-sectional studies were assessed using the National Institute of Health Quality Assessment Tool (NIH-QAT). Two reviewers independently applied the quality criteria to each study included. The findings were reported narratively following a content analysis approach by developing themes.

Applicability/external validity:

The authors present their findings and applicability to the enablers/barriers found to accessing DR screening by country income setting. For example, in the high income countries, most of the barriers to access were related to processes of DR screening, while in low income countries, barriers were related to major system factors such as unavailability of services, lack of human resources and infrastructure. Additionally, the authors acknowledged that their review was limited by the lack of consideration of generalisability in the original studies, and that more research is needed to determine which approach to address generalisability provides better results than others.

Geographic focus:

The geographic focus of the included studies in this review is mainly on high income countries, with 72.7% (56/77) of the studies conducted in HICs such as the United Kingdom, the United States, Germany, France, Ireland, Singapore, Canada, Oman, Hong Kong, South Korea, Australia, Taiwan, Italy and the Netherlands. The review also included studies from upper, low and middle income countries, but they were much fewer in number. Only 4.8% (3/63) of the studies were from LICs (sub-Saharan Africa, Tanzania and Nepal), 14.2% (11/77) from LMICs (Indonesia, India, Yemen, Kenya, Myanmar, Nigeria and Bangladesh) and 9.1% (7/77) from UMICs (Turkey, Iran, Mediterranean countries and China).

Summary of quality assessment

Overall, there is low confidence in the conclusions about the effects of this study due to the identified limitations. The authors did not avoid publication and language bias in the review as only peer-reviewed studies written in English were included in the review. Furthermore, findings were not reported or analysed according to the risk of bias of included studies.