Rates of refusal to participate in research studies among men and women.

Studies have indicated that, among persons with serious mental illness, women may be less likely to participate in clinical research studies than men. This study examined refusal rates by gender in four recent studies that included persons with a range of diagnoses and that used various interventions and methods. Examination of the four studies indicated that women are no more likely than men to decline to participate in studies but that women may be underrepresented in target populations. When feasible, oversampling may be useful to increase the participation of women or of any other underrepresented demographic group in research studies.