Population-based estimates of the burden of pneumonia hospitalizations in Hong Kong, 2011-2015.

Up-to-date data on the burden of disease are important to identify patients with unmet needs and to optimize healthcare resources. We aimed to characterize the burden of pneumonia hospitalizations in Hong Kong and inform targeted healthcare policies for pneumonia control in the era of global aging. This was a population-based study using a territory-wide administrative electronic health record system that covers all public hospitals of Hong Kong. Patients admitted to public hospitals, from 2011 to 2015, with a diagnosis of pneumonia at discharge were identified based on the International Classification of Diseases-Ninth Revision-Clinical Modification Codes (480-486 and 487.0). Incidence, inpatient case-fatality, all-cause fatality, 28-day readmission, hospital length of stay, and healthcare costs were assessed for seven age strata. We identified 323,992 patients (median age 80 years, 44.4% female) with hospitalized pneumonia (organism unspecified 84.2%; bacterial pneumonia 12.3%; viral pneumonia 2.5%; others 1.0%). Annual incidence was 955.1 per 100,000 population, with a 10.6% decrease from 2011 to 2015. Case-fatality, all-cause fatality, and 28-days readmission risks were 13.8, 21.6, and 19.5%, respectively. The average hospital length of stay was 14.1 days with corresponding direct costs of $9348 USD per episode in the monetary value of 2015. Individuals aged ≥ 65 years accounted for over 75% of pneumonia-related hospitalizations, 90% of deaths, and the majority of healthcare costs. Hospitalized pneumonia represents a considerable health and economic burden in Hong Kong, especially in older adults. The study provides a population-level baseline estimate for further cost-effective evaluation of targeted strategies for pneumonia control.