Table 1.
Baseline characteristics of the study subjects of blood donors aged 40–64 years and incidence rates of intrahepatic cholangiocarcinoma.
| N | (%) | ICC incident cases | Person-years (×105) | Incidence rate of ICC (per 105 person-years) | 95% Confidence interval* of ICC incidence rate (per 105 person-years) | |
|---|---|---|---|---|---|---|
| All cases | 154 814 | 100.0 | 11 | 12.50 | 0.88 | 0.44–1.58 |
| Age at blood donation (years) | ||||||
| 40–49 | 90 223 | 58.3 | 2 | 7.29 | 0.27 | 0.03–0.99 |
| 50–54 | 35 308 | 22.8 | 4 | 2.85 | 1.41 | 0.38–3.59 |
| 55–59 | 20 668 | 13.4 | 4 | 1.67 | 2.40 | 0.64–6.13 |
| 60–64 | 8615 | 5.6 | 1 | 0.69 | 1.44 | 0.02–8.06 |
| Sex | ||||||
| Male | 84 205 | 54.4 | 7 | 6.81 | 1.03 | 0.41–2.12 |
| Female | 70 609 | 45.6 | 4 | 5.68 | 0.70 | 0.19–1.80 |
| ALT (KU) | ||||||
| 19 or lower | 127 757 | 82.5 | 7 | 10.32 | 0.68 | 0.27–1.40 |
| 20–39 | 23 666 | 15.3 | 2 | 1.91 | 1.05 | 0.12–3.78 |
| 40 or over | 3391 | 2.2 | 2 | 0.27 | 7.36 | 0.83–26.74 |
| Cholesterol (mg/dL) | ||||||
| 139 or lower | 4533 | 2.9 | 0 | 0.37 | 0.00 | 0.00–12.60 |
| 140–199 | 82 575 | 53.3 | 8 | 6.67 | 1.20 | 0.52–2.36 |
| 200 or over | 67 706 | 43.7 | 3 | 5.46 | 0.55 | 0.11–1.61 |
| Hepatitis B/C virus infection | ||||||
| HBsAg+ | 2519 | 1.6 | 2 | 0.22 | 9.08 | 1.02–32.82 |
| anti-HCV+ | 1927 | 1.2 | 1 | 0.16 | 6.34 | 0.08–34.77 |
| All negative | 150 368 | 97.1 | 8 | 12.12 | 0.66 | 0.28–1.30 |
None of the subjects was positive for human immunodeficiency virus or human T-cell lymphotropic virus type 1. All negative: tested negative for both anti-HCV and HBsAg. ALT, alanine aminotransferase; HBsAg+, tested positive for Hepatitis B surface antigen and negative for Hepatitis C virus antibody; anti-HCV+, tested positive for anti Hepatitis C virus antibody and negative for Hepatitis B surface antigen. *95% confidence interval was calculated by Byar’s approximation of the exact Poisson test.