Objective: To characterize the clinical research methods published in the Revista de Investigación Clínica for the past 20 years.
Design: Comparative study of methods used in the RIC articles published in 3-years periods representing three decades (1972-74, 1982-84, 1992-94).
Results: Out of 273 original papers, 218 (80%) were of clinical research. There was an increased percentage of longitudinal vs cross-sectional studies, with cohort and randomized clinical trials showing the largest increase. The total number of research manuscripts also increased.
Conclusion: The clinical research methods of the papers in the RIC have shown an increased rate of designs with a higher scientific value.