%0 Journal Article %T Gross Domestic Product (GDP) and productivity of schizophrenia trials: an ecological study %A Carina Moll %A Ursula Gessler %A Stephanie Bartsch %A Hany El-sayeh %A Mark Fenton %A Clive Adams %J BMC Psychiatry %D 2003 %I BioMed Central %R 10.1186/1471-244x-3-18 %X Ecological study ¨C investigating the relationship between four economic/demographic variables and number of schizophrenia RCTs per country. The variable with closest correlation was used to predict the expected number of studies.GDP closely correlated with schizophrenia trial output, with 76% of the total variation about the Y explained by the regression line (r = 0.87, 95% CI 0.79 to 0.92, r2 = 0.76). Many countries have a strong tradition of schizophrenia trials, exceeding their predicted output. All nations with no identified trial output had GDPs that predicted zero trial activity. Several nations with relatively small GDPs are, nevertheless, highly productive of trials. Some wealthy countries seem either not to have produced the expected number of randomised trials or not to have disseminated them to the English-speaking world.This hypothesis-generating study could not investigate causal relationships, but suggests, that for those seeking all relevant studies, expending effort searching the scientific literature of Germany, Italy, France, Brazil and Japan may be a good investment.Most randomised trials are produced in the USA. Certainly, when it comes to trials relevant to the care of people with schizophrenia, certain countries have a strong tradition of trialling, and others have not [1]. This study investigates whether certain accessible economic and/or demographic variables are, in some way linked, and can be predictive of productivity of schizophrenia trials.The Cochrane Schizophrenia Group has constructed a unique collection of reports of randomised controlled trials relevant to schizophrenia [2]. In this collection a single electronic record is made per study and the multiple references/reports/presentations of that study are appended to that single record. This attempt to decrease the confusion caused by 'salami' publication is made possible using custom made specialised reference/study management software [3]. A study-based register affords an opportun %U http://www.biomedcentral.com/1471-244X/3/18