A systematic review of relapse measurement in randomized controlled trials of relapse prevention in first-episode psychosis.

The prevention of relapse is an important treatment goal in first-episode psychosis. Randomized controlled trials (RCTs) provide the gold standard methodology for evaluating interventions for relapse prevention. Properly designed RCTs which include relapse as a treatment outcome should rigorously operationalize psychotic relapse. The aim of this systematic literature review was to evaluate according to six criteria the operationalization of relapse in RCTs of clinical innovations for the prevention of relapse in first-episode psychosis. Through a systematic literature search of relevant RCTs in first-episode psychosis patients, eight pharmacological and eight non-pharmacological trials, published between 1982 and 2009, were identified. Readmission to a psychiatric hospital was the most common definition of psychotic relapse. Five studies did not measure relapse using any standardized or validated observer-rated instruments. The majority of the studies did not specify a duration criterion for relapse. Only three studies satisfied six criteria for the adequate operationalization of relapse. These results raise concerns regarding the internal and external validity of these research findings. There is an urgent need for a standardized, universally adopted set of criteria for psychotic relapse with appropriate specification of measurement instruments for use in future RCTs.