Content and quality of 10,000 controlled trials in schizophrenia over 60 years

Abstract

Objective: To carry out an up-to-date comprehensive survey of the content and quality of intervention trials relevant to the treatment of people with schizophrenia.

Design: Data were extracted and analyzed from 10,000 trials on the Cochrane Schizophrenia Group's Register.

Main outcome measures: Source, type and date of publication, country of origin, language, size of trial, interventions, and outcome measures.

Results: In the last decade, there has been a great increase in the number of trials relevant to schizophrenia and an improvement in the accessibility to reports. The number of trials per year is rising (currently ∼600/year) with China now producing 25% of the annual total. The number of reports of trials is increasing at an even greater rate due to multiple publications. Drug trials still dominate (83%) although an increasing proportion of studies are now evaluating psychological therapies (21%). Trials remain small (median 60 people) and often employ new nonvalidated outcomes scales (2194 different scales were employed with every fifth trial introducing a new rating instrument).

Conclusions: A more collaborative, pragmatic, and patient-centered approach is necessary to produce larger schizophrenia trials. Wider consultation and careful consideration of all relevant perspectives would result in trials with greater clinical utility and direct value to people with the illness and their families or carers.

Fig. 1.

Number of trials and number of reports across time