[Influence of Gender on Clinical Research]

Objective: To analyze clinical trials performed in our setting for the past three years from a gender-related standpoint.

Material And Methods: A retrospective study of 101 trials in which the pharmacy department of a 1,240-bed university hospital took part.

Data Sources: protocols and summary reports by the pharmacy department, Gecos software program, trial follow-up cards, reception records, sample dispensation and returns, and yearly reports.

Results: 17 trials included women only, 13 trials included men only, and 71 trials included patients of both genders. In female-only trials the most commonly studied condition was breast cancer (70.6%), the most common phases were phase III (47.1%) and II (41.2%) and the most commonly studied drugs were docetaxel (17.7%) and trastuzumab (11.8%). In male-only trials the most commonly studied condition was erectile dysfunction (92.3%), the most common phase was phase III (76.9%) and the most commonly studied drugs were tadalafil (38.5%) and vardenafil (30.8%). In trials without gender-related inclusion criteria the most commonly studied conditions included colon cancer (11.3%), lung cancer (11.3%), and renal failure (9.9%); the most common phase was phase III (57.7%) and the most frequently assayed drugs were interferon alpha-2a, gemcitabine and ribavirin. Overall participation rate was 62.3% for males and 37.7% for females.

Conclusions: a) Regardless of gender, the most commonly studied condition was cancer, with breast cancer being most common in female-only trials and erectile dysfunction in male-only trials; b) male and female participation followed a 2:1 ratio in trials without gender-related inclusion criteria; and c) phase III was most common amongst all trials considered, with phase II having a relevant role in women-only trials as per guidelines favoring inclusion in early trials.