Table 1.

Estimates of the Number Needed to Screen and the Number of Excess Prostate Cancer Diagnoses to Prevent One Death from Prostate Cancer during the Indicated Follow-up Interval.^*

Variable	No. Needed to Screen (95% CI)	No. of Excess Diagnoses (95% CI)
16 Yr of follow-up: empirical estimate from ERSPC	570 (380–1137)	18 (12–35)
25 Yr of follow-up: conservative model estimate	385 (273–687)	11 (8–20)

^*Model estimates are based on extrapolation of deaths from prostate cancer among men who received a diagnosis of prostate cancer during the first 16 years of follow-up of the European Randomized Study of Screening for Prostate Cancer (ERSPC), under the assumption that the relative mortality reduction would continue with additional follow-up. Confidence intervals are based on 95% confidence limits of the 16-year empirical estimates of mortality. (For model assumptions and details, see the Supplementary Appendix.) ERSPC protocols varied among sites. Men underwent randomization between the ages of 55 and 69 years and at most centers were screened every 4 years, with referral to biopsy when prostate-specific antigen levels were more than 3.0 ng per milliliter. The stopping age varied from 67 to 78 years of age.