Decision curve analysis, laboratory model. The dotted line is for base model (age and total prostate specific antigen (PSA)); the dashed line is for base model plus free PSA; the thin black solid line is for full model (age, total PSA, free PSA, intact PSA, and human kallikrein 2). As a comparison, the thin gray line is for the strategy of biopsying all men and the thick black line for biopsying no men. (a) The net benefit, interpreted as the number of cases of prostate cancer identified per patient keeping the rate of unnecessary biopsy constant. (b) The reduction in the rate of unnecessary biopsy keeping number of cases of prostate cancer identified constant.