THE INTERNATIONAL DIFFUSION OF THE CLINIC AL-TRIALS CARRIED OUT IN SPAIN - ANALYSIS THROUGH THEIR PUBLICATION IN SCIENTIFIC JOURNALS

BACKGROUND: Few studies have evaluated the clinical trials carried out in Spain and published in international journals. The present study h as analyzed this situation over the period from 1981 to 1990. METHODS: Spanish studies including <<clinical trial>> as a key word present in Excerpta Medica CD (Drugs and Pharmacology) or MEDLINE in the CD-ROM version were evaluated. RESULTS: TWO hundred forty-one original articl es were obtained. The number of clinical trials was relatively stable from 1981 to 1986 (n = 8-15) increasing to a maximum from 1986 to 1988 (n = 64) with a posterior decrease. The languages of publication were English (51 %) and Spanish (49 %). A significant increase was observe d in the number of articles published in English (p < 0.01) in the las t five years. Phase III and IV clinical trials were the most frequent (89 %) followed by those of phase II (9 %) and phase I (2 %). The open design predominated in the phase Ill-IV trials (58 %) over the double blind trials (37 %) and the single blind trials (5 %). Among the form er 70 % were comparative and 57 % followed randomized treatments. The clinical trials were published in 112 journals, Medicina Clinica (n = 32) and Current Therapeutic Research Clinical and Experimental(n = 6) were the most frequently used in Spanish and English, respectively. Tw o hundred sixty-three drugs were studied in the clinical trials, cispl atin was the most frequently studied (n = 10). The most commonly studi ed pharmacologic groups were antiinfectious (n = 40) and cytostatic (n = 35). The number of randomized clinical trials increased significant ly after 1986 (p < 0.01) CONCLUSIONS: An increase in the number of cli nical trials published in international journals was observed with pre ference for publication in English. The growing presence of randomized double blind clinical trials suggests an improvement in the quality o f the clinical trials performed in Spain, particularly after 1986.