Fig. 2
Forest plot for the association between current smoking and prostate cancer. RR, relative risk; CI, confidence interval; PCa, prostate cancer; US, United States; UK, United Kingdom. a Rohrmann et al. [49] had two sub-populations. b RR and 95% CI were calculated using frequency distributions. c RR and 95% CI were converted from HR and corresponding 95% CI using the formula RR ≈ (1-e HR x ln (1−P0))/P0 (P0 refers to the incidence rate of PCa in the control group). d Weights were from random effects analysis