Serum testosterone (continuous and 5 nmol/L increments) in observational studies (prospective, retrospective) and its effects on PCa events (stage and grade). Studies/analyses only show multivariable analyses to minimize confounding effects. Magnitudes of association (ORs, RRs, etc.) and 95% CIs (25-49). PCa, prostate cancer; OR, odds ratio; RR, relative risk.