Trends and characteristics of hospitalisation and mortality among centenarians in old-age homes and communities: a territory-wide study in Hong Kong, 2012-2021.

Objective: To examine the trends and characteristics of hospitalisation and mortality among centenarians residing in old-age homes (OAHs) and their community-dwelling counterparts in Hong Kong over the past decade. Methods: This retrospective analysis used electronic admission records of all centenarians (aged ≥100 years) admitted to public hospitals in Hong Kong between 2012 and 2021. Centenarians were categorised based on living arrangements at initial admission: OAHs or community dwellings. Trends in hospitalisation rates, mortality and length of stay (LOS) were assessed using the Mann-Kendall test. All-cause readmission and mortality risks at 7, 30, 90, 180 and 365-day postdischarge were compared using logistic and Cox regressions with a random hospital-specific effect. Results: The study analysed 41 221 episodes involving 8360 centenarians, with 4739 (56.7%) from OAHs. The crude hospitalisation rate decreased from 626 in 2012 to 169 per 1000 population in 2021, while total hospitalisations rose by 69.7% (from 3039 to 5156 episodes). Crude mortality rates fell from 239 to 80 per 1000 population, but total deaths increased by 123% (from 418 to 932 persons). Total LOS increased by 85% (from 22 548 to 41 760 days), although average LOS per episode remained stable. In-hospital mortality rates increased significantly for OAH residents (from 42% to 50%) and community-dwelling centenarians (from 29% to 58%). Centenarians in OAHs exhibited longer stays, more frequent admissions and higher mortality from respiratory diseases, alongside increased long-term readmission and mortality risks at 180 and 365-day postdischarge. Conclusions: The past decade observed a substantial increase in hospitalisations and mortality among Hong Kong centenarians. Those residing in OAHs were associated with a more complex clinical profile, including longer LOS, more frequent admissions and higher long-term risks of readmission and mortality. These findings underscore the need for specialised care models tailored to the unique vulnerabilities of this growing demographic, particularly in institutional settings.