Diabetes, in‐hospital mortality trends and life expectancy loss among a 21.8‐million population in Beijing, China, 2012–2024

AIMS: Diabetes is a major contributor to premature mortality, but whether declining mortality trends in the general population have been matched among people with diabetes remains uncertain in China. METHODS: Retrospective cohort study based on hospitalisation records from 207 public general hospitals in Beijing (excluding community-level primary care facilities and speciality hospitals), serving the city's 21.8 million registered residents, 2012-2024. Temporal trends by Joinpoint regression, and life expectancy using abridged life tables. RESULTS: Among 452,186 in-hospital deaths, 146,282 (32.3%) had diabetes. In-hospital mortality was 32.0 per 1000 admissions in patients with diabetes and 13.4 in those without diabetes. During 2012-2019, among adults ≥75 years, mortality declined in patients without diabetes (AAPC, -1.2%; p = 0.026) but remained stable in those with diabetes (AAPC, 0.9%; p = 0.082); among adults <75 years, declines were smaller in patients with diabetes (-2.4% vs. -4.0%). Life expectancy-estimated from hospitalisation records as a comparative measure of survival among admitted patients-was 5.0 years lower in patients with diabetes than in those without diabetes. Loss was greater with earlier diagnosis; diagnosis at ages 20-24 years was associated with a 4.8-year reduction. Loss was larger in women than in men (5.8 vs. 2.4 years). CONCLUSIONS: Diabetes was associated with substantially higher in-hospital mortality and smaller mortality improvements. Earlier diagnosis was linked to greater life expectancy loss, with disproportionate losses among women.