Do STD clinic patients who consent to sexual health research differ from those who decline? Findings from a randomized controlled trial with implications for the generalization of research results

Objectives: This study determined whether patients from an STD clinic who agreed to participate in behavioral research are representative of the overall patient population. Study Design: Patients attending an STD clinic (N = 2694) were invited to participate in sexual risk-reduction research. Those who accepted (consenters) were compared to those who declined (nonconsenters) on data obtained from the medical chart. Results: Overall, 58% of eligible patients consented to participation. Logistic regression analyses indicated that consenting to participate was associated with female sex [odds ratio (OR) = 1.86], nonwhite race (OR = 2.16), having completed at least some college (OR = 1.70), being a returning patient (OR = 1.21), and having a greater number of sexual partners in the past 3 months (OR = 6.95) (all P's <0.05). Conclusions: Patients who agreed to participate had more education, were more familiar with the setting, and were more vulnerable to HIV/STD (as suggested by epidemiologic research). Efforts to enhance participation by an even greater percentage of patients might target these predictors of participation by enhancing risk awareness and providing preemptive reassurances regarding the research process and setting.