COVID-19 outcomes among patients with sickle cell disease or sickle cell trait compared to the general population: a systematic review and meta-analyses

Individuals with sickle cell disease (SCD) and sickle cell trait (SCT) face an increased risk of complications from COVID-19 due to their susceptibility to infections and venous thromboembolism. We selected 28 studies from 3228 references in bibliographic databases to compare COVID-19 outcomes (hospitalization, ICU admission, need for ventilatory support, thromboembolic events, and mortality) between patients with SCD or SCT and control patients. Compared to control patients, the pooled risk of hospitalization was not significantly higher in those with SCT (odds ratio [OR] 1.13, 95% confidence interval [CI] 0.94-1.34) but the pooled risk of death was higher (OR 1.43, 95% CI 1.14-1.78). Compared to controls patients, those with SCD had a much higher pooled risk of hospitalization (OR 7.79, 95% CI 5.13-11.81) and a non-different risk of death once hospitalized (OR 0.82, 95% CI 0.62-1.10), resulting in an overall increased risk of death (OR 1.94, 95% CI 1.26-2.98).