Changes in emergency department visits, diagnostic groups and 28-day mortality associated with the COVID-19 pandemic: a territory-wide, retrospective, cohort study

Wai, Abraham K.C.; Wong, Carlos K.H.; Wong, Janet Y.H.; Xiong, Xi; Chu, Owen C.K.; Wong, Man Sing; Tsui, Matthew S.H.; Rainer, Timothy H.

Objective We aimed to evaluate and characterize the scale and relationships of emergency department visits and excess mortality associated with the early phase of COVID-19 pandemic for the territory of Hong Kong. Methods We conducted a territory-wide, retrospective, cohort study to compare the ED visits and related impact of the COVID-19 pandemic on mortality. All ED visits at 18 public acute hospitals in Hong Kong between January 1st and August 31st, 2019 (n=1,426,259); and 2020 (n=1,035,562) were included. The primary outcome was all-cause mortality in the 28 days following an ED visits. The secondary outcomes were weekly number of ED visits and diagnosis-specific mortality. Results ED visits decreased by 27.4% from 1,426,259 in 2019 to 1,035,562 in 2020. Overall period mortality increased from 28,686 (2.0%) in 2019 to 29,737 (2.9%) in 2020. The adjusted odds ratio (OR) for 28-day, all-cause mortality in the pandemic period of 2020 relative to 2019 was 1.26 (95%CI 1.24-1.28). Both genders, age >45 years, all triage categories, all social classes, ED visits periods and for epilepsy (OR 1.58, 95%CI 1.20-2.07), lower respiratory tract infection and airway disease had higher adjusted ORs for all-cause mortality. Conclusions A significant reduction in ED visits in the first eight months of the COVID-19 pandemic was associated with an increase in deaths certified in ED. Government must make provision to encourage patients with alarming symptoms, mental health conditions and co-morbidities to seek timely emergency care, regardless of the pandemic.