How many patients do we need? Predictors of consent to participate in clinical research studies in orthopaedic trauma.

Abstract

To characterize the recruitment rates at a level-I trauma center enrolling for multiple prospective orthopedic trauma research studies and identify patient and study-related predictors of consent. We conducted a case control study to identify predictors of study consent. The authors categorized studies based on intensity of the study intervention (Low, Intermediate, or High). A 2-level generalized linear model with random intercept for study was used to predict study consent. This analysis includes data from ten federally funded studies conducted as part of a large, national consortium that were enrolling patients in 2013-2014.Patients/Participants: 334 patients were approached for at least one study and included in the analysis. N/A. Consent to participate in the research study. A total of 315 patients consented to be in a study (71% of approached patients). Consent rate varied by study (45-95%). No patient characteristics (race, age, or gender) were associated with consent. Patients approached for studies of intermediate intensity were 83% less likely to consent (OR=0.17; 95% CI: 0.04, 0.67), and those approached for studies of high intensity were 91% less likely to consent (OR=0.09; 95% CI: 0.03, 0.32). Patient factors were not associated with consent. Study intensity is a major driver of consent rates. Studies of higher intensity will require the study team to approach up to twice as many patients as the target enrollment. This study provides a framework that can be used in study planning and determination of feasibility. Level III. See Instructions for Authors for a complete description of levels of evidence.