In sensitivity analysis, men living in the highest compared with lowest quintile of county-level PSA screening at baseline (AHR, 0.94; 95% CI, 0.91-0.97; P < .001 for trend) and using cumulative updated average county-level screening through diagnosis (AHR, 86; 95% CI, 0.84-0.89; P < .001 for trend) had statistically significantly lower prostate cancer–specific mortality, although associations were attenuated. The gene discussed is KLK3; the disease is prostate carcinoma.