Abstract
Studies for patients with cancer often have low, but variable, recruitment. Retention is also variable and can prove problematic for successful study completion. This review aimed to estimate recruitment rate (RR), recruitment efficiency (RE), and dropout for exercise-related studies for the breast cancer population. In addition, this review aimed to address the gap in the literature of what factors are associated with recruitment and retention for exercise-related studies for the breast cancer population. PubMed, CINAHL, and ORRCA databases were searched. Peer-reviewed studies addressing recruitment in an exercise-related intervention for human adults, where >50% of the sample were participants with breast cancer, were included. Only studies written in English were included. Studies using a cross-sectional design were excluded. All identified studies were abstract and full-text screened. The proportion of RE and dropout were meta-analyzed, and the influence of predictors on RE and dropout were analyzed using metaregression. RR had a weighted average of 2.6 participants per week. Dropout (r = 0.64, P = 0.003) and race (r = -0.54, P = 0.024) were correlated with RR. Random-effects meta-analyses yielded pooled estimates of 0.30 and 0.16 for RE and dropout, respectively. Treatment group compensation (b = -0.07, SE = 0.03, P = 0.013) and monitoring status (b = -0.13, SE = 0.06, P = 0.023) were statistically significant predictors of RE, where increasing compensation and monitoring a study predicted lower RE. Age (b = -0.07, SE = 0.02, P = 0.003) and education (b = -0.06, SE = 0.03, P = 0.024) were statistically significant predictors of dropout, where increases in age and decreases in education predicted lower dropout. This review may help identify characteristics that improve recruitment and retention. Study characteristics (e.g., compensation and monitoring status) predicted RE, and participant characteristics (e.g., age and education) predicted dropout.