Trends in Mortality from Diabetes and Other Non-Communicable Diseases Among Sri Lankan Adults: A Retrospective Population-Based Study, 2004–2020/2021

<b>Background</b>: Non-Communicable Diseases (NCDs) are the leading cause of adult mortality worldwide, accounting for 74% of deaths. In Sri Lanka, assessing NCD mortality trends is essential for public health planning. This study evaluated trends in total and hospital-based NCD deaths from 2004 to 2020/2021, examining differences by disease category, age, and gender. <b>Methods</b>: Total NCD deaths (2004-2020; 2008 interpolated) were obtained from the Department of Census and Statistics, covering all registered deaths. Hospitalized deaths (2004-2021) were extracted from the Indoor Morbidity and Mortality Return (IMMR) dataset. Deaths were initially classified into nine major NCD categories based on ICD-11 codes and were subsequently consolidated into seven categories for the analysis. Age-adjusted mortality rates per 100,000 were calculated using the 2012 Sri Lankan Census. Percentage changes were assessed by age and gender, and trends tested using the Mann-Kendall method. <b>Results</b>: NCD mortality increased substantially, with differences between total and hospital deaths. Total deaths due to diabetes rose 169% and genitourinary causes 105%, whereas hospital deaths increased for the same condition by 34% and 123%, respectively. Women had higher total mortality, while men had higher hospital mortality across most NCDs. <b>Conclusions</b>: NCD deaths in Sri Lanka have risen over two decades, reflecting improved registration and gaps in early diagnosis and healthcare access. The greater increase in diabetes deaths outside hospital settings indicates possible under-diagnosis and suboptimal management of risk factors.