@Article{info:doi/10.2196/75635,
author="Ching, Christie J Y
and Chan, Sunny C L
and Lee, Teddy T L
and Pui, Hugo H H
and Leung, Bosco K H
and Wong, Man Sing
and Yamamoto, Tafu
and Tong, Chak Kwan
and Wang, Cantian
and Rainer, Timothy H
and Wai, Abraham K C",
title="Postpandemic Change in Demographic and Clinical Features of Patients With Omicron Who Were Hospitalized: Territory-Wide Retrospective Repeated Cross-Sectional Study in Hong Kong",
journal="JMIR Public Health Surveill",
year="2026",
month="Feb",
day="9",
volume="12",
pages="e75635",
keywords="emergency department; COVID-19; infectious disease epidemiology; Omicron; SARS-CoV-2",
abstract="Background: The Omicron variant of SARS-CoV-2 underwent several mutations since it was first identified in November 2021, with a large outbreak in Hong Kong in early 2022. Yet, local cases of Omicron infections persist, even though the COVID-19 pandemic ended in May 2023. Objective: This study aims to describe the changes in demographic and clinical characteristics of patients infected with COVID-19 across different Omicron waves in Hong Kong and determine whether the changes continued into the postpandemic period. Methods: This retrospective repeated cross-sectional study collected data on patients infected with COVID-19 admitted to public hospitals in Hong Kong between May 1, 2022, and May 31, 2024. These data were later categorized into 3 periods based on the Omicron strain. A subsequent age-stratified descriptive analysis was conducted on each characteristic to identify any significant differences across the periods. Results: First, the case fatality ratio significantly lowered among those older than 85 years (1.5{\%} proportion decrease, period 1: 11.6{\%}, period 2: 10.1{\%}, effect size: 0.02; P<.001). Second, most patients were Chinese (≥68.7{\%} per age group and period), and females were predominantly infected for those aged older than 85 years (≥56.9{\%} per period). Third, the Charlson Comorbidity Index scores in most age groups showed a predominant proportion of infected individuals with 0 scores (more than 70{\%} per period). Fourth, most cases were from slightly disadvantaged populations in Hong Kong (≥30.5{\%} per age group per period). Fifth, clinical management of Omicron hospitalizations showed lowered length of hospital stays among adults and older individuals (≥1 d decrease between periods 1 and 3, per age group), as well as increased administration of bronchodilators. Conclusions: Despite the decreasing incidence of Omicron cases admitted to public hospitals in Hong Kong, the increasing case fatality ratio with age suggests that long-term surveillance of COVID-19 should be maintained to prepare for potential mutations and outbreaks. ",
issn="2369-2960",
doi="10.2196/75635",
url="https://publichealth.jmir.org/2026/1/e75635",
url="https://doi.org/10.2196/75635"
}