Goteborg 2008.

Methods	As Goteborg 1994
Participants	As Goteborg 1994
Interventions	As Goteborg 1994
Outcomes	Colorectal cancer mortality at mean follow‐up time of 15 years and 9 months (range 11 years and 3 months to 19 years and 5 months) from first invitation; mean follow‐up time of 8 years and 8 months (range 6 years and 7 months to 13 years and 5 months) since last screening occasion. Compliance with screening = 61.8% in total (62.5% prevalence round, 59.9% 1st screening round, 63.9% 2nd round, 47.2% completed all screening rounds). Hemoccult sensitivity NR; Hemoccult specificity NR. Positive Predictive Value for CRC: 4.8% total (5.9% prevalence screen, 4.1% 1st screen, 4.1% 2nd screen). 86.7% positive FOBt overall attended complete diagnostic follow‐up which included FSig and DCBE (87.3% prevalence round, 89.7% 1st screening round, 81.1% 2nd round). No information on complications of diagnostic follow‐up. Number of CRC cases: Screening group = 721 (104 screen detected, 413 at follow‐up, 204 non‐participants); Control group = 754. Number of CRC deaths: Screening group = 252 (mortality rate = 0.53 per 1000 person‐years), Control group = 300 (mortality rate = 0.64 per 1000 person‐years). Deaths from all‐causes: Screening group = 10591 (mortality rate = 22.48 per 1000 person‐years), Control group = 10432 (mortality rate = 22.10 per 1000 person‐years); Mortality ratio: RR 1.02, CI 0.99 to 1.06. Mortality reduction: 16% (RR 0.84, CI 0.71 to 0.99). Comparison between accepting screening once versus Control: 24% (RR 0.76, CI 0.63 to 0.92).
Notes	Due to changes in the classification of ‘positive FOBt’ (see p1031) number of positive FOBt tests differ between 2008 publication and 1994 publication (1994 = 942 positive FOBt in prevalence round; 2008 = 801 positive FOBt in prevalence round; also, 1994 = 1019 positive FOBt in 1st screening round; 2008 = 846 positive FOBt in 1st screening round). Number of CRC cases from positive test same in both publications, however, number of adenomas10 mm or above differ (1994 = 129 Ss with adenomas 10 mm or above in prevalence round; 2008 = 114 Ss with adenomas 10 mm or above in prevalence round).
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	A ‐ Adequate