Long-term outcomes in patients with sickle cell disease and frequent vaso-occlusive crises

Background: The frequency of vaso-occlusive crises correlates with mortality in patients with sickle cell disease (SCD). We examined the degree to which a high number of hospitalization days for these events affected survival. Patients and Methods: We reviewed data for 58 adult patients with SCD (mean age, 29.9 +/- 7.3 years) treated at our hospital between 1986 and 1994 who had at least 100 hospitalization days during any of these years. Their mean follow up period was 6.65 years (median, 6.84 years; range, 0.15-14.51 years). Results: Thirty-five patients (60.3%) died during follow-up. in multivariate analysis that included age, gender, and numbers of transfusions and hospitalization days, only age was significantly associated with mortality. The National Cooperative Study of Sickle Cell Disease (CSSCD) estimates the 10-year mortality at 15% for all 20-year old SS patients and also for all 30-year-old women. For 30-year-old men, the CSSCD estimated a 10-year mortality of about 28%. Thus, the 60.3% mortality of our patients after a median follow-up of only 6.84 years was substantially higher. Fifty-one patients were still alive after 1992, when hydroxyurea became available for SCD. The median survival of 15 hydroxyurea-treated patients was 7.3 years, compared with 4.3 years in 36 patients who did not take the drug. Conclusions: Mortality for patients with SCD with a high number of hospitalization days was much higher than that expected for patients with SCD in general. There was a (nonsignificant) trend for longer survival in these severely ill patients if they took hydroxyurea.