Co-morbidities and mortality in patients with sickle cell disease in England: A 10-year cohort analysis using hospital episodes statistics (HES) data.

Patients with a primary diagnosis of sickle cell disease (SCD) with or without crisis during the 10-year period January 2009 to December 2018 were identified in the HES Admitted Patient Care (APC) dataset and matched with the Office for National Statistics (ONS) mortality dataset. Three sub-cohorts were defined: 'crises', 'transfusions' and 'other SCD'. APC records were examined for co-morbidities commonly associated with SCD and 10-year mortality rates compared with the general population. After data cleaning and exclusions, 9503 patients remained (entire cohort), with 1171, 201, and 8131 in crises, transfusions, and other SCD sub-cohorts, respectively. Median numbers of co-morbidities per patient were 2 (Interquartile range (IQR): 1-4), 2 (IQR: 1-3), and 1 (IQR: 0-2) in the crises, transfusions, and other SCD sub-cohorts, respectively. The majority of patients in the crises (63.2%) and transfusions (56.3%) cohorts had ≥2 co-morbidities, compared with 25.3% in the other SCD sub-cohort. Crude 10-year mortality rate was 5.3% (entire cohort), compared with 8.0% (crises) and 11.4% (transfusions) sub-cohorts; all rates were substantially higher than in age-sex matched general population. Our study adds further evidence that morbidity and mortality associated with SCD in England is high.