[The identification and description of clinical trials published in Spanish journals of general and internal medicine during the period of 1971-1995].

BACKGROUND: When faced with a therapeutic issue, the practice of evidence-based medicine requires efficient access to information derived from controlled clinical trials. The objectives of the study were to locate, with the greatest possible exhaustivity, all controlled clinical trials published in Spanish journals of general medicine, between 1971 and 1995 (25 years), to characterize them, and to incorporate them into the worldwide database of clinical trials maintained by the Cochrane Collaboration. METHODS: The controlled clinical trials have been identified by a systematic, manual review of all the Spanish journals of general and internal medicine. The results obtained have been compared with an exclusive electronic search in MEDLINE. A descriptive analysis of the characteristics of the localized controlled clinical trials was done. RESULTS: 68 journals of general and internal medicine have been identified, only 6 being indexed in MEDLINE. A search carried out exclusively using MEDLINE would imply the loss of one third of all controlled clinical trials. About 16 controlled clinical trials per year have been published in Spain in the area of general and internal medicine, most of them with important missing information. CONCLUSIONS: The limitations of searching only in MEDLINE have been shown once again. There are few controlled clinical trials published in Spain in the area of general and internal medicine, and in order to improve their quality and their diffusion is recommended that authors and editors adhered to the international consensus initiatives that are under way.