OBJECTIVES : To estimate expected value of sample information (EVSI) for a large RCT in the 2^nd phase of the DAFNEplus research programme.

METHODS : Phase 1 of programme involved developing DAFNEPlus by refining the 5 day DAFNE structured education course and adding novel post course support processes for adults with type 1 diabetes. Phase 2 is to conduct a large cluster randomised controlled trial (RCT) of DAFNEplus versus standard DAFNE. EVSI analysis took an UK NHS and personal social services perspective. We conducted an expert elicitation using the SHELF framework to estimate the uncertainty in effectiveness of DAFNEplus compared to DAFNE. The four experts included: medical experts; diabetes educators; health psychologists; and people with diabetes. Evidence on the effectiveness of current DAFNE was obtained from the REPOSE and DAFNE research database studies. The additional cost of DAFNEplus was calculated using nationally representative unit costs, expert opinion and the RCT costing. These data were incorporated into the Sheffield Type 1 Diabetes Policy Model, and a probabilistic analysis was conducted. The EVSI of conducting the proposed RCT was estimated using Sheffield Accelerated Value of Information (SAVI).

RESULTS : The mean ICERs from the probabilistic sensitivity analysis for DAFNEPlus versus DAFNE alone varied between £6,186 to £9,575 per QALY gained, well below the commonly used £20k UK threshold. The probability that DAFNEplus was cost-effective ranged from 0.57 to 0.866 at a £20,000 per QALY gained threshold. The associated EVSI of the DAFNEplus RCT and a two-year post-course follow-up ranged substantially across the scenario analyses with values up to £115.5m.

CONCLUSIONS : This study demonstrated that the refined DAFNEplus course was potentially cost-effective in all scenarios and that in most scenarios there was substantial value in conducting the DAFNEplus RCT. This analysis informed the decision making process to go-ahead with the proposed trial.