Information, Networks and Rewards to Optimise Adherence to Diabetic Services

Background: Diabetes affects some 10% of rural-dwellers in southern China. Demand for care of both diabetes and DR is low in this population: Only 25% are in care for diabetes (vs 100% of a matched urban cohort), 0% were being treated for DR (vs 55% of the urban cohort) and 31% said they were likely/very likely to accept diabetic eyecare when it was described to them (vs 78% of the urban group). A simple intervention of informational SMS reminders could significantly increase knowledge about DR and satisfaction with care among rural dwellers, while tripling their compliance with scheduled eye examinations. However, even in the group receiving the SMS reminders, over half failed to present for exams. More effective interventions are needed.

Participants: All the participants with treated diabetes or HbA1c >=6.5% from the Guangdong (Yangjiang) centre of our population-based Rural Diabetic Eye Disease Survey. They must be aged 50-90 years, own a cell phone (ownership is > 95% in the area), have no mobility limitations precluding routine clinic visits or bilateral blindness (<6/120), and be capable of giving informed consent.

Randomisation: To avoid contamination, we are clustering recruitment and randomisation at the level of village and inviting participants in the two study groups to the Yangjiang eye screening centre for follow-up on different clinic days. Block randomization, at village level, will be balanced by the distribution of education levels and travel times from screening centre.

Intervention. All groups will be offered a brief video, already created and piloted, explaining basic information about diabetes and diabetic eye disease. The Intervention group will also receive (i) non-cash rewards (free eye care and modest mobile phone top ups in return for attendance at retinopathy screenings), the value of which will increase with the risk of vision loss (based on existing level of eye disease and HbA1c). (ii) Informational reminders delivered by SMS text 1 day and 1 week prior to scheduled eye exams. In keeping with health economic research,3 the reminders will emphasize anticipated regret: "Your next eye screening visit is next week, on dd/mm/yy. If you miss your eye screening visit, you might regret this if you subsequently lose your vision."; and (iii) peer and village health worker (VHW) networking (supported by the existing Orbis CREST project). Peer supporters will be a nominated family member or friend who has regular contact with the patient and a VHW or a community member with diabetes who has been trained to run monthly group educational sessions in the local village on optimum self-care and self-management of diabetes/DR. An important function of the family member or peer supporter is also to re-inforce the SMS informational reminders before the scheduled clinic visit.

Primary outcome measure: Proportion of scheduled eye care visits attended over 1 year. Secondary outcomes, not the direct target of our intervention, but which might be improved by a behavioural spill-over effect, will include: follow-up HbA1c; medication adherence; retinopathy grade and visual acuity in the better seeing eye.

Power and sample size: Assuming an effect size d= 0.44, and an attrition of 15% over two years, a full trial of 412 patients (42 villages in each of the two groups and 206 patients per group) would have 90% power (two sided alpha error 0.05).