Effect of a tailored leaflet to promote diabetic retinopathy screening among young adults with type 2 diabetes: a randomised controlled trial.

Background: Young adults with type 2 diabetes (aged 18-39 years) are at risk of early onset and rapid progression of diabetic retinopathy, the leading cause of blindness and vision loss in working age adults. Early detection via retinal screening can prevent most vision loss, yet uptake among this priority population is consistently lower than the general diabetes population. We aimed to test the effect of a tailored, evidence-based brief health behaviour change intervention (leaflet) on self-reported uptake, and previously identified social cognitive determinants of retinal screening. Methods: A pragmatic, two-arm randomised controlled trial was conducted from September 2014 to April 2015. Participants were stratified by prior screening uptake (Yes/No) and randomly allocated to intervention (leaflet) or ‘usual care’ control (no leaflet). Primary outcome was self-reported screening uptake four weeks post-intervention for ‘No’ participants who had not previously screened for diabetic retinopathy. Secondary outcome variables were changes in knowledge, attitudes, normative beliefs, intention and behavioural skills for all participants, irrespective of prior screening behaviour. To assess intervention effects on secondary outcome variables, we conducted independent samples t-tests (two-tailed) on pre-post change scores. Results: 129 young adults (26% no prior retinal screen) completed baseline; 101 completed post-intervention. Power to determine effect on the primary outcome was curtailed by low recruitment of individuals with no prior retinal screen and loss to follow-up. Attrition was associated significantly with country of birth, language spoken at home, and marital status. Significant intervention effect was observed for one secondary outcome variable: knowledge of diabetic retinopathy (p=.03) with moderate effect (partial eta squared h2=.05); no adverse effects were reported. Control group participants received the leaflet at study completion. Conclusions: This study confirms that a well-designed eye health and retinal screening promotion leaflet can increase knowledge of diabetic retinopathy, an important screening predictor. The study highlights the challenges of conducting ‘real-world’ health behaviour change research with this priority population, providing insights for clinicians and researchers. Strategies to recruit, engage and retain hard-to-reach populations are discussed including nonconventional alternatives to randomised controlled trial designs. Trial registration: ACTRN12614001110673, UTN No.: U1111-1161-9803. Registered 20 October 2014 - retrospectively registered https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=367127