LONG-TERM SURVIVAL AFTER BLOOD-TRANSFUSION

Background: Look-back investigations of populations of patients admitt ed to major tertiary-care hospitals in the 1980s found a 2-year posttr ansfusion mortality rate in excess of 50 percent. To quantify the asso ciation of blood transfusion with mortality in a more broadly based po pulation, a cohort of all residents of a United States county who unde rwent transfusion in 1981 was studied. Study Design and Methods: Retro spective cohort study comprised 802 county residents. Complete follow- up (until death or for 10 years) was available on 93.9 percent. Result s: The median length of survival was 95.0 (+/- 2.5) months. Twenty-fou r per cent of patients died within 1 year after the transfusion, 30 pe rcent within 2 years, 40 percent within 5 years, and 52 percent within 10 years. The relative risk of death within 10 years increased by 4.1 percent per unit of red cells (p<0.0001), by 1.2 percent per unit of platelets (p = 0.0003), and by 7.3 percent per unit of fresh-frozen pl asma (p = 0.0018) received in 1981, after adjustment for the effects o n mortality of age, gender, and number of days of hospitalization in 1 981. Conclusion: Receipt of a blood transfusion can be used as a descr iptive epidemiologic index of morbidity in the general population, as it is independently predictive of mortality, adding to the predictive value of age, gender, and previous hospitalization. There is a dose-re sponse relationship between the amount of blood components received an d a reduction in the subsequent length of survival. However, when a co unty's entire population is studied, posttransfusion mortality due to underlying disease is substantially lower than that previously reporte d in look-back investigations.