Designing a randomised controlled trial to test whether public acknowledgement improves phosphate control among dialysis patients: lessons from social science research

Abstract

BackgroundPeople on kidney dialysis are prone to high phosphate levels, which carry an increased risk of cardiovascular disease and death. Successful control of phosphate relies on patient behaviour change, avoiding certain foods and taking numerous drugs with meals. Social science research has shown that people change social behaviours like voting and giving to charity if they are promised public acknowledgement (Ariely et al., 2009; Cotterill et al., 2012; Green and Gerber, 2010). This research will test whether these findings are relevant in a health setting: is public acknowledgment an effective way of promoting behaviour change among dialysis patients?MethodA cluster randomised controlled trial among dialysis patients. The cluster design mirrors the way dialysis care is provided, with shifts of patients, each attending three times a week. Dialysis shifts will be randomly assigned to an intervention or control group. Patients attending the intervention dialysis shifts will be advised that their phosphate levels will be monitored and the names of those who maintain phosphate within recommended limits will be displayed in the dialysis unit. The control group will receive a placebo letter. Otherwise, treatment will be as usual. The primary outcome measure will be phosphate level, obtained in routine, monthly blood tests. DiscussionThis study highlights interesting differences between health service and neighbourhood settings when communicating about randomised controlled trials of behaviour change interventions. Differences include the acceptability of RCTs; acceptability of behaviour change interventions; and attitudes to public involvement and ethics.