UC Davis

Bleeding is a known complication of sickle cell disease (SCD) and includes hemorrhagic stroke, hematuria, and vitreous hemorrhage. However, the incidence of bleeding events in patients with SCD has not been well described. We present a retrospective, population-based study examining the cumulative incidence of bleeding in 6423 patients with SCD from 1991 to 2014. We also studied risk factors associated with bleeding and the effects of bleeding on mortality, using Cox proportional hazards regression models. We used California emergency department and hospitalization databases to identify patients with SCD with intracranial hemorrhage, gastrointestinal (GI) bleeding, hemophthalmos, gross hematuria, epistaxis, menorrhagia, and other bleeding events. The cumulative incidence of any first bleeding event at age 40 years was 21% (95% confidence interval [CI], 19.8%-22.3%), increasing with age to 41% by age 60 years (95% CI, 38.8%-43.1%). The majority of bleeding events were GI (41.6%), particularly from the upper GI tract. A higher bleeding risk was associated with increased frequency of hospitalization (hazard ratio [HR], 2.16; 95% CI, 1.93-2.42), venous thromboembolism 180 days before bleeding event (HR, 4.24; 95% CI, 2.86-6.28), osteonecrosis of the femoral head (HR, 1.25; 95% CI, 1.08-1.46), and ischemic stroke (HR, 1.65; 95% CI, 1.20-2.26). Bleeding was also associated with a twofold increased risk for death (HR, 2.09; 95% CI, 1.82-2.41) adjusted for other SCD-related complications. Our novel finding of a high incidence of bleeding in patients with SCD, particularly from the upper GI tract, suggests that patients with SCD may be predisposed to bleeding, with possible etiologies including increased use of nonsteroidal anti-inflammatory drugs, mucosal infarction from vascular occlusion by sickled red blood cells, and increased stress ulceration from frequent hospitalization.