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* | 30 964 | 50-80 | ≤18 | 0.08 (−0.04 to 0.21) | 0.23 (0.06 to 0.40) | 11 rounds, annual |
| Minnesota (biennial)20,21* | 30 981 | 50-80 | ≤18 | −0.09 (−0.23 to 0.05) | 0.04 (−0.14 to 0.23) | 6 rounds, biennial |
| Nottingham18 | 150 251 | 45-74 | 11 (8-18) | 0.09 (0.02 to 0.16) | 0.13 (0.04 to 0.22) | 2-5 rounds, biennial |
| Funen17† | 61 933 | 45-75 | ≤10 | 0.10 (−0.02 to 0.22) | — | 5 rounds, biennial |
| Goteborg19 | 68 308 | 59-65 | (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 York26† | 61 004 | 40-64 | ≤10 | 0.10 (0.00 to 0.20) | — | 4 rounds, annual |
| Combined Swedish trials22‡ | 110 385 | 55-74 | 16 (14-22) | 0.10 (0.04 to 0.16) | 0.14 (0.06 to 0.21) | — |
| Malmo I22,24§ | 25 299 | 45-70 | 19 (18-20) | 0.023 | 0.095 | 6-8 rounds, every 18-24 months |
| Ostergotland16,22§ | 44 743 | 40-74 | 17 (16-19) | 0.029 | 0.052 | 2-4 rounds, every 24-33 months |
| Stockholm22,25§ | 26 532 | 40-65 | 15 (14-16) | 0.032 | 0.030 | 2 rounds, every 28 months |
| Goteberg22,23§ | 13 811 | 40-59 | 13 (13-14) | 0.070 | 0.10 | 4-5 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.