Table 1

 Trial characteristics

Sample size (No)Age range (years)Follow-up range (years)Absolute risk reduction (95% CI)Intervention
At 8 years At 12 years
Colorectal cancer screening (fecal occult blood test)
Minnesota (annual)20,21*30 96450-80≤180.08 (−0.04 to 0.21)0.23 (0.06 to 0.40)11 rounds, annual
Minnesota (biennial)20,21*30 98150-80≤18−0.09 (−0.23 to 0.05)0.04 (−0.14 to 0.23)6 rounds, biennial
Nottingham18150 25145-7411 (8-18)0.09 (0.02 to 0.16)0.13 (0.04 to 0.22)2-5 rounds, biennial
Funen1761 93345-75≤100.10 (−0.02 to 0.22)5 rounds, biennial
Goteborg1968 30859-65(11-19)0.003 (−0.08 to 0.09)0.07 (−0.04 to 0.19)2-3 rounds (rescreened 1, 2, or 10 years)
Breast cancer screening (mammography)
Health Insurance Plan-New York2661 00440-64≤100.10 (0.00 to 0.20)4 rounds, annual
Combined Swedish trials22110 38555-7416 (14-22)0.10 (0.04 to 0.16)0.14 (0.06 to 0.21)
Malmo I22,24§25 29945-7019 (18-20)0.0230.0956-8 rounds, every 18-24 months
Ostergotland16,22§44 74340-7417 (16-19)0.0290.0522-4 rounds, every 24-33 months
Stockholm22,25§26 53240-6515 (14-16)0.0320.0302 rounds, every 28 months
Goteberg22,23§13 81140-5913 (13-14)0.0700.104-5 rounds, every 18 months

*Annual and biennial groups share a common control group (n=15 394) which was split for the meta-analysis.

†Studies did not publish cancer specific mortality data to 12 years’ follow-up.

‡Absolute risk reductions apply to patients aged 55-74 years only.

§Absolute risk reductions apply to all women, including those aged 40-54 years. Because we did not have access to the underlying data, we were unable to calculate confidence intervals for the published absolute risk reductions at eight and 12 years.