Hospitalizations and mortality during the first year of the COVID-19 pandemic in Hong Kong, China: An observational study

Hualei Xin; Peng Wu; Jessica Y Wong; Justin K Cheung; Eric H Y Lau; Gabriel M Leung; Benjamin J Cowling; Joshua Nealon

doi:10.1016/j.lanwpc.2022.100645

Hospitalizations and mortality during the first year of the COVID-19 pandemic in Hong Kong, China: An observational study

Lancet Reg Health West Pac. 2022 Nov 23:30:100645. doi: 10.1016/j.lanwpc.2022.100645. eCollection 2023 Jan.

Authors

Hualei Xin¹, Peng Wu^{1

2}, Jessica Y Wong¹, Justin K Cheung¹, Eric H Y Lau^{1

2}, Gabriel M Leung^{1

2}, Benjamin J Cowling^{1

2}, Joshua Nealon¹

Affiliations

¹ World Health Organization Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China.
² Laboratory of Data Discovery for Health, Hong Kong Science and Technology Park, Hong Kong Special Administrative Region, China.

Abstract

Background: Hong Kong followed a strict COVID-19 elimination strategy in 2020. We estimated the impact of the COVID-19 pandemic responses on all-cause and cause-specific hospitalizations and deaths in 2020.

Methods: Interrupted time-series analysis using negative binomial regression accounting for seasonality and long-term trend was used on weekly 2010-2020 data to estimate the change in hospitalization risk and excess mortality occurring both within and out of hospitals.

Findings: In 2020, as compared to a 2010-2019 baseline, we observed an overall reduction in all-cause hospitalizations, and a concurrent increase in deaths. The overall hospitalization reduction (per 100,000 population) was 4809 (95% CI: 4692, 4926) in 2020, with respiratory diseases (632, 95% CI: 607, 658) and cardiovascular diseases (275, 95% CI: 264, 286) contributing most. The overall excess mortality (per 100,000 population) was 25 (95% CI: 23, 27) in 2020, mostly among individuals with pre-existing cardiovascular diseases (12, 95% CI: 11, 13). A reduction in excess in-hospital mortality (-10 per 100,000, 95% CI: -12, -8) was accompanied by an increase in excess out-of-hospital mortality (32, 95% CI: 29, 34).

Interpretation: The COVID-19 pandemic might have caused indirect impact on population morbidity and mortality likely through changed healthcare seeking particularly in youngest and oldest individuals and those with cardiovascular diseases. Better healthcare planning is needed during public health emergencies with disruptions in healthcare services.

Funding: Health and Medical Research Fund, Collaborative Research Fund, AIR@InnoHK and RGC Senior Research Fellow Scheme, Hong Kong.

Keywords: COVID-19; Excess mortality; Hospitalization; In-hospital mortality; Out-of-hospital mortality.