Determinants of a subject's decision to participate in clinical anesthesia research.

Background: A top priority for research studies is to ensure that potential participants receive adequate information to make a truly informed decision. Understanding patient experiences with the recruitment process may identify areas for improvement in the consent process. We examined which factors were associated with the decision to consent in a clinical research study.

Methods: Patients scheduled for elective surgery were asked to complete a questionnaire about the consent process, immediately after being approached to participate in an anesthesia-related research study. Sociodemographic characteristics, preoperative levels of anxiety and depression, medical comorbidities, factors that may affect decision to participate in a research study, and study design features were collected. A multivariable logistic regression model was estimated to identify factors associated with providing consent. Performance of the prediction model was assessed using the receiver operating characteristic curve. Internal validity was assessed by a bootstrap analysis.

Results: In all, 282 participants completed the questionnaire. Of those, 179 (63%) had consented to participate in research, and 103 (37%) had declined to participate. In the multivariable logistic regression model, the odds of providing consent were higher for males (odds ratio [OR] [95% confidence interval]=2.49 [1.29-4.79]) and for patients with higher levels of patient comfort (OR=1.84 [1.22-2.78]). The odds of providing consent were lower for protocols that require additional testing (OR=0.15 [0.06-0.39]) and patients with higher levels of concern about blood sampling (OR=0.70 [0.54-0.90]) or worry about study risks (OR=0.72 [0.55-0.95]). Bootstrap analysis revealed a stable model with high internal validity.

Conclusions: The 2 strongest predictors of consent were male gender and comfort; predictors of refusal were protocol type that requires additional testing, greater concern about blood sampling and study risks, and lower overall patient comfort with the study. These patient and study characteristics may inform modification of the consent process for clinical research studies and facilitate the development of more accurate enrollment projections and strategies.