Much to improve: A survey of controlled Nordic schizophrenia trials

The Cochrane Schizophrenia Group's Register of Trials was surveyed for repo rts on trials of Nordic origin. Quality assessment of reports was undertake n in accordance with the Jadad scale. Two hundred and twenty reports coveri ng 181 trials from four Nordic countries were found, with most originating from Sweden. The Nordic trials were smaller than those from other countries and with a few exceptions had inadequate statistical power to produce any precise conclusions. Interventions applied were almost entirely biologic. E ven though about half of the Nordic trial reports were of low quality, the mean quality score of these reports was significantly better than that of t he rest of the world (U = 147260, df = 2035, P = 0.017). In the future tria ls should be designed to recruit adequate sample sizes to be able to provid e clinically useful data, and trial reporting must be improved. The use of prospective controlled trials should be extended to evaluation of psychosoc ial treatments of schizophrenia.