Barriers to and enablers of diabetic retinopathy screening attendance: a systematic review of published and grey literature

Methodological quality of the review: Medium confidence

Author: Graham-Rowe E, Lorencatto F, Lawrenson JG, Burr J, Grimshaw JM, Ivers NM, Peto T, Bunce C, Francis JJ; WIDeR-EyeS Project team.

Region: United States of America (USA), United Kingdom (UK), Australia, Canada, Asia, Africa, Europe and South America.

Sector: Diabetic retinopathy screening

Sub-sector: interventions, uptake, cost-effectiveness

Equity focus: None specified

Review type: Other review

Quantitative synthesis method: Narrative synthesis

Qualitative synthesis method: Not applicable

Background:

Understanding the theoretical determinants (such as barriers and enablers) of screening behaviour is an important step in intervention development and in interpretation of the results of evaluations of interventions. In phase 2 of this study, identification of barriers and enablers provides an evidence base to assess the extent to which existing QI interventions address the theoretical determinants of attendance behaviour, to offer guidance as to why some interventions might work better than others and to identify which theoretical determinants are likely to mediate the effects of interventions.

Objectives:

Identify the published and grey literature reporting perceived barriers and enablers associated with DRS attendance

Extract reported barriers/enablers and categorise them according to theoretical domains framework (TDF) / Consolidated Framework for Implemented Research (CFIR) intervention domains

Identify key content themes within domains, regarding barriers to and enablers of diabetic retinopathy screening (DRS) attendance

Apply pre-specified criteria to identify the likely importance of TDF/CFIR domains in influencing DRS attendance.

Main findings:

In total, 65 non-randomized studies were included in the review; 41 studies used quantitative methods only, 18 used qualitative methods only and six used mixed methods. Forty-seven studies used quantitative methods in full or as part of a mixed-method design. Of these 47 studies, 37 (79%) used a cross-sectional survey design, nine (19%) used a follow-up design and one (2%) was a report of a questionnaire development study. Twenty-four studies used qualitative methods in full or as part of a mixed-method design. Of these 24 studies, 19 (79%) were descriptive studies that had no specific analytical or theoretical approach, one (4%) was part of an evaluation of a QI intervention, one (4%) used a theoretical framework (TDF), one (4%) used a grounded theory approach, one (4%) used a case-based approach and one (4%) was a service evaluation. Twenty-nine (45%) of the studies were carried out in the USA, 12 (18%) in the UK, four (6%) in Australia, three (5%) in Canada, 10 (15%) in Asia, four (6%) in Africa, two (3%) in Europe and one (2%) in South America.

The following theoretical domains were likely to influence attendance: ‘environmental context and resources’ (reported by 50 studies), ‘social influences’ (32 studies), ‘knowledge’(reported by 33 studies), ‘memory, attention and decision processes’ (31 studies), ‘beliefs about consequences’ (25 studies) and ‘emotions’ (22 studies).

Methodology: 

Studies were included if they reported primary data relating to barriers and enablers that might hinder or facilitate patient attendance at DRS. Such barriers or enablers included organizational, emotional, cognitive, behavioural and social factors; however, they were required to be potentially modifiable. Studies were excluded if they did not signal investigations of primary data relating to barriers and/or enablers in the title. Authors included studies reported in English, conducted within the time period from January 1990 to March 2016. Participants with Type 1 and type 2 diabetes and eligible for DRS were included in the review.

Authors searched MEDLINE, EMBASE, PsycINFO, Web of Science, CENTRAL and ProQuest from 1990 to 2016. Reference lists of included studies were also reviewed as part of the search strategy. OpenGrey databases were also searched for additional studies. One reviewer screened the titles and abstracts of identified studies and another reviewer screened about 10% of the titles and abstracts. Inter-rater reliability was calculated. Two authors collaboratively extracted data of included studies. One reviewer assessed the quality of the included studies using items selected from the Critical Appraisal Skills Programme tool and mixed methods appraisal tool. A second reviewer assessed a random sample of studies.

Applicability/external validity:

Authors report that the combined content and framework analysis identified six TDF domains as representing the most important factors potentially influencing screening attendance: (1) ‘environmental context and resources’, (2) ‘social influences’, (3) ‘knowledge’, (4) ‘memory, attention and decision processes’, (5) ‘beliefs about consequences’ and (6) ‘emotions’. Hence, the hypothesis arising from this review is that interventions that target these domains are more likely to be effective at increasing screening attendance.

Geographic focus:

Authors report that 15% of the included studies covered barriers/enablers from the perspective of specific ethnic groups (e.g. African Americans, American Indians, Aboriginal Canadians, people of South Asian or Hispanic origin). However, they do not report the applicability of findings to low- and middle-income countries.

Summary of quality assessment:

Overall, there is medium confidence in the conclusions about the effects of this study. Although authors conducted a thorough search of the literature, authors did not avoid bias when screening studies for inclusion and extract data of included studies. Authors appropriately addressed limitations of the review and included studies.