Limited evidence to support the use of adjudication committees to verify findings of RCTs

Limited evidence to support the use of adjudication committees to verify findings of RCTs

A large meta-analysis of 47 randomized controlled trials (RCTs) totaling 275,078 patients found that, on average, treatment effect estimates for subjective outcome events assessed by onsite assessors and those assessed by adjudication committees were similar.

The new article in the Cochrane Database of Systematic Reviews is co-authored by Lee Aymar Ndounga Diakou, Ludovic Trinquart, Asbjørn Hróbjartsson, Caroline Barnes, Amelie Yavchitz, Philippe Ravaud, and Isabelle Boutron, from Cochrane France and INSERM U1153 (Paris, France).

Many clinical trials assess the benefit of new treatments on non-fatal events. Such outcomes frequently lack standard definitions and are subjective in their determination. Central adjudication is the process of reviewing clinical data by a group of independent physicians to assess consistently and to validate events.

It is widely recommended that multicentre RCTs should have a central adjudication committee, rather than relying on the outcomes reported by assessors at the relevant site, where the decision might be subjective. These central adjudication committees are commonly used, especially in large-scale trials. However, the adjudication process can be very time- and resource-consuming. There is very limited evidence to support the use of adjudication committees.

This meta-analysis examined RCTs across medical areas to evaluate the impact of central adjudication on the estimates for treatment effect that they produced. All selected trials reported the same subjective clinical event outcome, assessed by both an onsite assessor and an adjudication committee. The authors investigated whether using the event data from the adjudication committee produced different treatment effect estimates than the data from onsite investigators.

The researchers combined the findings of 47 RCTs  and found no evidence of difference, on average, in treatment effect estimates from onsite assessors and adjudication committees (combined ratio of odds ratios: 1.00, 95% confidence interval 0.97 to 1.04).

When the researchers divided the data into whether or not the onsite assessors knew the patient's allocated treatment in the RCT and the various ways of submitting data to adjudication committees, they found that there might be important differences between onsite assessment and adjudication committee, depending on which methods are used. The combined ratio of odds ratio was 1.00 (95%CI 0.96 to 1.04) when onsite assessors were blinded; 0.76 (95% CI 0.48 to 1.12) when the adjudication committee assessed events identified independently from unblinded onsite assessors; and 1.11 (95% CI 0.96 to 1.27) when the adjudication committee assessed events identified by unblinded onsite assessors. There was a statistically significant interaction between these subgroups (P = 0.03). The authors conclude that their findings question the benefit of having an adjudication committee for a randomized trial and highlight the need to revise the planning and functioning of adjudication committees.

Ndounga Diakou LA, Trinquart L, Hróbjartsson A, Barnes C, Yavchitz A, Ravaud P, Boutron I. Comparison of central adjudication of outcomes and onsite outcome assessment on treatment effect estimates. Cochrane Database of Systematic Reviews 2016, Issue 3. Art. No.: MR000043. DOI: 10.1002/14651858.MR000043.pub2

2 May 2016