Rate of admission and readmission to the ED among patients with severe asthma

<bold>Background:</bold> One third of asthma-related emergency department (ED) admissions in Canada result in readmissions within 90 days. However, the clinical and economic burden associated with readmissions remains unclear, especially among those with more severe asthma. This study characterized the health care resource use (HCRU) associated with readmissions among patients with GINA 4/5 severity. <bold>Methods:</bold> Adults with ≥1 asthma-related ED admission (baseline asthma severity of GINA steps 4/5) were identified from the Alberta provincial health administrative database (2015-2020). Rate of ED readmissions, hospital admission, mortality, specialist follow-up, and total costs were assessed within 90 days of the initial admission. Results were presented for all ED events and stratified by readmission status. <bold>Results:</bold> A total of 11,208 asthma ED admissions from 7,168 patients (mean[SD] age of 36.3[13.7] years; 61% female) were identified. In the 90-day post ED period, 39% were readmitted to the ED; 5% were hospitalized. While 30% had any outpatient follow-up, only 11% were with respiratory-related specialists; 3.5%, specifically for asthma. With an ED readmission, mean (SD) total costs estimated in the 90-day period were significantly higher ($3,376 [$8,669]) than without readmission ($326 [$1,580]); rates of hospitalization and mortality were also higher (12.8% vs. 1.1%; 0.3% vs 0.1%). <bold>Conclusions:</bold> The study findings suggest that readmissions among those with more severe asthma were frequent and associated with higher HCRU and costs, and worse clinical outcomes, while specialist follow-up was rare. Timely and appropriate follow-up post ED admission is a potential opportunity to reduce further readmissions and HCRU.