"And Then He Got into the Wrong Group": A Qualitative Study Exploring the Effects of Randomization in Recruitment to a Randomized Controlled Trial.

Background: Randomized controlled trials (RCTs) are regarded as the most internally valid means of estimating the effectiveness of complex public health interventions, but the recruitment of participants can be difficult. The aim of this study was to explore factors that may have affected the recruitment of employees with musculoskeletal disorders (MSDs) to a multicenter worksite health promotion program from the perspective of recruiting case managers.

Methods: Factors in recruitment to the RCT were explored using three focus group discussions with case managers.