Potentially unnecessary and wasteful clinical trial research detected in cumulative meta-epidemiological and trial...

The objective was to estimate the presence and extent to which potentially unnecessary and therefore maybe wasteful clinical trials regarding relevant interventions and outcomes in major clinical areas had been conducted.

From current Cochrane collaboration systematic reviews in major medical fields (e.g., cardiovascular disease, cancer, psychiatry), 13 different comparisons were sampled. A cumulative meta-analysis was conducted for each and trial sequential analysis applied to determine when in the course of evidence accrual evidence was found sufficient to reach a reliable conclusion. Trials published afterward were considered potentially unnecessary. Sensitivity analysis is performed, for example, to determine if findings could be explained by a delayed perception of published findings when planning new trials.

In 8/13 cases, potentially unnecessary research was detected to an extent of between 12% and 89% of all participants in trials that might not have been needed. In three of these cases with high proportions (69-89%) of potentially unnecessary research, this finding was found basically unchanged in sensitivity analysis, when only trials published 3 or 5 years after sufficient evidence had already been published were considered potentially wasteful.

The reasonableness of claims to relevance of additional trials needs to be much more carefully evaluated in the future. Cumulative, information size bases analysis might be included in systematic reviews. Research policies to prevent unnecessary research from being done need to be developed.