Objective Current guidelines recommend screening for hepatocellular carcinoma (HCC) in high-risk populations. However, the effectiveness of screening in reducing mortality has been challenged. In addition, it is unclear which subgroups benefit most from HCC screening.

Design This nationwide cohort study identified a total of 52 823 newly diagnosed HCC patients between 1 January 2002 and 31 December 2007. These HCC patients were classified into the following cohorts according to the time intervals in which they received ultrasonography screening: 0–6 months (6M), 7–12 months (12M), 13–24 months (24M), 25–36 months (36M) and not screened within 3 years (never screened). The chance to receive curative therapy and 5-year cumulative mortalities were calculated after adjusting for lead-time bias.

Results Chances to receive curative therapy among the 6M, 12M, 24M, 36M and never screened cohorts were 24.3% (95% CI 23.7% to –24.9%), 26.9% (95% CI 25.7% to 28.2%), 22.9% (95% CI 21.8% to 24.1%), 21.3% (95% CI 19.9% to 22.8%) and 18.3% (95% CI 17.8% to 18.8%), respectively. Compared with the 6M cohort, adjusted HRs of mortality for the 12M, 24M, 36M and never screened cohorts were 1.11 (95% CI 1.07 to 1.15), 1.23 (95% CI 1.19 to 1.28), 1.31 (95% CI 1.26 to 1.37) and 1.47 (95% CI 1.43 to 1.51) (all p<0.001), respectively. On multivariable subgroup analyses, the associations between shorter screening intervals and better survival were observed in nearly all subgroups, especially in younger patients, patients without diabetes and patients with hepatitis B infection.

Conclusions Shorter ultrasonography screening intervals are associated with reduced overall mortality in HCC patients in a dose-dependent manner.