Emergency department utilization patterns in adults living with sickle cell disease

Most adults with sickle cell disease (SCD) attend the emergency department (ED), with significant interindividual and temporal variability. To identify the patterns of ED use, we analysed data from adults with SCD followed at a French reference centre who had ≥1 ED visit between 1 October 2013 and 31 December 2019. We used a survival model to estimate the cumulative risk of ED visits and its variability over time and applied clustering methods on these two dimensions to identify typical patterns of ED utilization. Among 656 adults (9080 ED visits), two clusters emerged: a low-use group with 529 individuals (81%) and 2924 ED visits (32%) and a high-use group with 127 individuals (19%) and 6156 ED visits (68%). All high-use group members experienced ED visits in bursts, defined as at least three visits within 3 months and at least three times more than during the previous 3 months. Bursts were uncommon in the low-use group (5% of individuals). Among individuals experiencing bursts, two ED visits less than a month apart increased the risk of another ED visit within the next month (adjusted HR 3.51 [95% CI 2.95-4.16]). Understanding factors triggering bursts of ED visits in adults with SCD may enable targeted interventions.