Baseline subject characteristics to predict compliance with study-mandated prostate biopsy in men at risk of prostate cancer: Results from REDUCE.

6 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 8,062 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, 20% of men did not undergo a 2-year biopsy.On multivariable analysis, non-North American region was predictive of 35-55% 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 40-49% increased likelihood of undergoing a 2-yea...