Baseline subject characteristics predictive of compliance with study-mandated prostate biopsy in men at risk of prostate cancer: results from REDUCE

Background:study compliance is crucial when the study outcome is determined by an invasive procedure, such as prostate biopsy. to investigate predictors of compliance in study-mandated prostate biopsies, we analyzed demographic, clinical and reported lifestyle data from the reduce trial.methods:we retrospectively identified 8025 men from reduce with at least 2 years of follow-up, and used multivariable logistic regression to test the association between baseline demographic and clinical characteristics and undergoing the study-mandated prostate biopsy at 2 years. we then examined whether missing any of these data was associated with undergoing a biopsy.results:in reduce, 22% of men did not undergo a 2-year biopsy. on multivariable analysis, the non-north american region was predictive of 42–44% increased likelihood of undergoing a 2-year biopsy (p⩽0.001). being enrolled at a center that enrolled >10 subjects (2nd and 3rd tertile) was associated with a 42–48% increased likelihood of undergoing a 2-year biopsy (p<0.001). in addition, black race predicted 44% lower rate of on-study 2-year biopsy (odds ratio (or)=0.56; p=0.001). finally, missing one or more baseline variables was associated with a 32% decreased likelihood of undergoing a 2-year biopsy (or=0.68; p<0.001).conclusions:in reduce, men outside north america, those at higher volume centers and those with complete baseline data were more likely to undergo study-mandated 2-year biopsies. given prostate biopsy is becoming increasingly utilized as an endpoint in trials that are often multi-national, regional differences in compliance should be considered when designing future trials. likewise, efforts are needed to ensure compliance in low-volume centers or among subjects missing baseline data.