Characteristics and outcomes of patients with COVID-19 who return to the emergency department: a multicentre observational study by the Canadian COVID-19 Emergency Department Rapid Response Network (CCEDRRN)

Objective Unplanned return emergency department (ED) visits can reflect clinical deterioration or unmet need from the original visit. We determined the characteristics and outcomes of patients with COVID-19 who return to the ED for COVID-19-related revisits.Methods This retrospective observational study used data for all adult patients visiting 47 Canadian EDs with COVID-19 between 1 March 2020 and 31 March 2022. Multivariable logistic regression assessed the characteristics associated with having a no return visit (SV=single visit group) versus at least one return visit (MV=return visit group) after being discharged alive at the first ED visit.Results 39 809 patients with COVID-19 had 44 862 COVID-19-related ED visits: 35 468 patients (89%) had one visit (SV group) and 4341 (11%) returned to the ED (MV group) within 30 days (mean 2.2, SD=0.5 ED visit). 40% of SV patients and 16% of MV patients were admitted at their first visit, and 41% of MV patients not admitted at their first ED visit were admitted on their second visit. In the MV group, the median time to return was 4 days, 49% returned within 72 hours. In multivariable modelling, a repeat visit was associated with a variety of factors including older age (OR=1.25 per 10 years, 95% CI (1.22 to 1.28)), pregnancy (1.86 (1.46 to 2.36)) and presence of comorbidities (eg, 1.72 (1.40 to 2.10) for cancer, 2.01 (1.52 to 2.66) for obesity, 2.18 (1.42 to 3.36) for organ transplant), current/prior substance use, higher temperature or WHO severe disease (1.41 (1.29 to 1.54)). Return was less likely for females (0.82 (0.77 to 0.88)) and those boosted or fully vaccinated (0.48 (0.34 to 0.70)).Conclusions Return ED visits by patients with COVID-19 within 30 days were common during the first two pandemic years and were associated with multiple factors, many of which reflect known risk for worse outcomes. Future studies should assess reasons for revisit and opportunities to improve ED care and reduce resource use.Trial registration number ClinicalTrials.gov, NCT04702945.