Pulmonary embolism in sickle cell disease: a case-control study.

INTRODUCTION: A pulmonary embolism (PE) is a leading cause of mortality in hospitalized patients, yet the prevalence of PE in sickle cell disease (SCD) and its relation to disease severity or intrinsic hypercoagulability are not established.
METHODS: We estimated inpatient PE incidence and prevalence among SCD and non-SCD populations in Pennsylvania, and compared severity of illness and mortality, using Pennsylvania Health Care Cost Containment Council (PHC4) discharge data, 2001-2006. Risk factors for PE were assessed in a case-control study of discharges from the University of Pittsburgh Medical Archival Records System (MARS).
RESULTS: The incidence of inpatient PE was higher in the SCD PA population than in the non-SCD Pennsylvania population, 2001-2006. The PE prevalence among SCD discharges ≤ 50 years of age, 0.57%, was similar to that in non-SCD Pennsylvania discharges, 0.60%, and unchanged after adjustment for race. Among SCD discharges, those developing PE were significantly older, with a longer length of stay, greater severity of illness and higher mortality, P < 0.001, than SCD without a PE. Among PE discharges, SCD had a similar severity of illness, P = 0.77, and mortality, P = 0.39, but underwent fewer computerized tomographic scans, P = 0.006, than non-SCD with PE. In the local case-control study, no clinical or laboratory feature was associated with PE.
CONCLUSIONS: The incidence of PE is higher and chest computed tomography (CT) utilization is lower in SCD than non-SCD inpatients, suggesting that PE may be under-diagnosed.