National trends in hospitalizations for sickle cell disease in the United States following the FDA approval of hydroxyurea, 1998-2008.

ABSTRACT

BACKGROUND: Patients with sickle cell disease (SCD) can suffer frequent hospital admissions for painful vasoocclusive crises. Hydroxyurea was approved by the FDA in 1998 to decrease the morbidity of SCD, but nationwide hospitalizations for SCD in the United States since 1998 have not been evaluated. We hypothesized that the availability of hydroxyurea for SCD would be associated with a decrease in hospitalizations for SCD over time. OBJECTIVE: To assess trends in hospitalization and length-of-stay in hospital for SCD in the United States, 1998 through 2008. RESEARCH DESIGN: Retrospective cohort study of SCD-related hospital discharges in the Nationwide Inpatient Sample of US hospital discharges. SUBJECTS: All discharges in the Nationwide Inpatient Sample associated with a principal diagnosis of SCD in blacks, 1998 through 2008. MEASURES: Trends in hospitalization rates and average length-of-stay in hospital for SCD. RESULTS: We found 216 (95% confidence interval, 173.3-258.7) SCD-related hospitalizations per 100,000 US blacks in 1998 and 178.4 (95% confidence interval, 144.2-212.5) in 2008, but no consistent yearly decrease, 1998 through 2008 (P=0.30). Conversely, the length-of-stay in hospital in 1998 was 5.38 days and in 2008 was 5.18 days, an absolute change of 0.2 days and a downward trend that was statistically significant. CONCLUSIONS: Between 1998 and 2008, there was not a steady decrease in hospitalization rates for the population of SCD in the United States. On the contrary, there was a decline in length-of-stay in hospital over this time. Hydroxyurea underuse is well documented. Efforts to increase hydroxyurea use may help to reduce hospitalization rates.