Table 3.
Relative risks of selected liver diseases in relation to the maximum disease excess score among all contributing blood donors, presented stratified by calendar period of transfusion.
| Maximum disease excess score among contributing blood donors* | a) Before 1992
|
b) In or after 1992
|
||
|---|---|---|---|---|
| Events/person-years | Hazard ratio (95% CI)† | Events/person-years | Hazard ratio (95% CI)† | |
| All liver disease | ||||
| < 0.0 recipients | 2,421/1,258,218 | 1.00 (ref) | 7,208/2,689,162 | 1.00 (ref) |
| 0.0, i.e. no prior donations | 2,582/1,193,869 | 0.98(0.93-1.04) | 6,079/2,107,759 | 0.98(0.95-1.02) |
| 0.1-2.5 recipients | 4,619/1,707,270 | 1.07(1.01-1.13) | 8,878/2,407,898 | 1.03(1.00-1.07) |
| 2.6-5.0 recipients | 373/87,091 | 1.40(1.24-1.58) | 199/43,287 | 0.92(0.79-1.08) |
| >5.0 recipients | 56/5,354 | 2.93(2.19-3.92) | 0/65 | 0.00 (n.e.) |
| All liver disease (excluding viral hepatitis) | ||||
| < 0.0 recipients | 2,236/1,330,080 | 1.00 (ref) | 6,730/2,782,299 | 1.00 (ref) |
| 0.0, i.e. no prior donations | 2,352/1,232,839 | 0.97(0.92-1.04) | 5,564/2,154,594 | 0.98(0.94-1.01) |
| 0.1-2.5 recipients | 3,779/1,637,517 | 1.05(0.98-1.11) | 7,572/2,286,312 | 1.03(0.99-1.07) |
| 2.6-5.0 recipients | 189/65,483 | 1.08(0.92-1.27) | 147/37,640 | 0.86(0.71-1.03) |
| >5.0 recipients | 14/1,462 | 3.17(1.80-5.60) | 0/100 | 0.00 (n.e.) |
| Liver cirrhosis | ||||
| < 0.0 recipients | 757/1,688,770 | 1.00 (ref) | 1,563/3,523,687 | 1.00 (ref) |
| 0.0, i.e. no prior donations | 724/1,435,348 | 0.91(0.81-1.01) | 1,276/2,556,476 | 0.98(0.90-1.06) |
| 0.1-2.5 recipients | 816/1,147,641 | 1.06(0.95-1.19) | 795/1,215,650 | 1.05(0.95-1.16) |
| >2.5 recipients | 36/25,272 | 1.69(1.19-2.41) | 3/4,758 | 1.03(0.33-3.24) |
| Viral hepatitis | ||||
| < 0.0 recipients | 826/1,778,734 | 1.00 (ref) | 1,346/3,725,046 | 1.00 (ref) |
| 0.0, i.e. no prior donations | 746/1,466,346 | 1.00(0.90-1.11) | 1,234/2,669,623 | 1.05(0.96-1.14) |
| 0.1-2.5 recipients | 884/1,003,571 | 1.24(1.11-1.39) | 533/894,575 | 1.00(0.89-1.13) |
| >2.5 recipients | 94/30,399 | 3.35(2.62-4.29) | 1/2,216 | 0.87(0.12-6.27) |
The diseases excess score was computed time-dependently so that for each new donation we calculated the difference between the observed and expected number of diseased patients among all previous recipients of each donor. Thus, a case excess score below zero implies that there are fewer than expected diseased patients among previous recipients and a riskiness score above zero implies that the number of events is higher than expected. Because most recipients received transfusions from more than one donor, the highest case excess score of all donors who contributed blood unit to each recipient was used in the statistical model. The donor disease excess score only included the number of diseased patients among previous recipients, i.e. not the disease status of the index patient.
Hazard ratios were adjusted for patient age, sex and ABO blood group, calendar year of transfusion, region of residence, as well as number of transfusions.