[International diffusion of clinical trials carried out in Spain. An analysis based on 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 has 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 articles 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 observed in the number of articles published in English (p < 0.01) in the last 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 III-IV trials (58%) over the double blind trials (37%) and the single blind trials (5%). Among the former 70% were comparative and 57% followed randomized treatments. The clinical trials were published in 112 journals, Medicina Clínica (n = 32) and Current Therapeutic Research Clinical and Experimental (n = 6) were the most frequently used in Spanish and English, respectively. Two hundred sixty-three drugs were studied in the clinical trials, cisplatin was the most frequently studied (n = 10). The most commonly studied pharmacologic groups were antiinfectious (n = 40) and cytostatic (n = 35). The number of randomized clinical trials increased significantly after 1986 (p < 0.01).


CONCLUSIONS
An increase in the number of clinical trials published in international journals was observed with preference for publication in English. The growing presence of randomized double blind clinical trials suggests an improvement in the quality of the clinical trials performed in Spain, particularly after 1986.
Baños
J E
JE
Departament de Farmacologia i Psiquiatria, Universitat Autònoma de Barcelona.
Bosch
F
F
Bigorra
J
J
Guardiola
E
E
D002986:Clinical Trials as Topic; D010506:Periodicals as Topic / Q000706:statistics & numerical data*; D011643:Publishing / Q000706:statistics & numerical data*; D013030:Spain
Difusión internacional de los ensayos clínicos realizados en España. Un análisis a través de su publicación en revistas científicas.