Patterns of COVID-19 mortality during the second and third waves in Sri Lanka: a cross-sectional study from a tertiary care center

Introduction & objectives: The COVID-19 pandemic has claimed over 6.8 million lives globally, with varying impacts across different healthcare systems. Sri Lanka reported 591 and 15,800 deaths during the Second and Third Waves, respectively. This study investigates COVID-19 mortality patterns at a major tertiary care hospital in Sri Lanka during the pandemic, describing demographic characteristics of deaths, examining comorbidity patterns, and comparing deaths by vaccination status and treatment setting. 

Methods: A descriptive cross-sectional analysis was conducted using medical records of COVID-19-related deaths registered at Colombo North Teaching Hospital between November 2020 to December 2021. Among 1,269 deaths identified, 1,004 with complete clinical data were included in the analysis. Data were sourced from hospital records, supplemented by telephone interviews with family members for missing information, following informed consent. Statistical analyses included Mann-Whitney U tests and Pearson’s Chi-squared tests for group comparisons.

 Results: There were 8,531 COVID-positive admissions during the study period, with 1,269 total recorded deaths (hospital mortality rate 14.9%); 1,004 deaths had complete data (79.1%) and were analysed. Median age of the study population was 72 years (IQR: 62–79, range: 19–99), with males constituting 57.2% of the cohort. Diabetes (61.6%), hypertension (36.9%), and coronary artery disease (14%) were the predominant comorbidities, with 37.2% having multiple comorbidities. COVID-19 pneumonia was the primary cause of death (83%). Most deaths (78.3%) occurred among unvaccinated individuals, while a smaller proportion (21.7%) occurred among those who had received at least one vaccine dose. Unvaccinated individuals were older, had longer hospital stays, and exhibited more severe symptoms compared to their vaccinated counterparts. 

Conclusions: Most deaths occurred among older adults and individuals with diabetes or hypertension. Strengthening vaccination outreach and clinical management of high-risk groups remains important. The lower proportion of vaccinated individuals observed among the deceased is notable; however, further population-level data are required to formally evaluate vaccine effectiveness. These descriptive findings underscore the need to prioritise high-risk populations in vaccination campaigns. These findings provide guidance for strengthening pandemic preparedness in resource-constrained settings, with potential applications across similar healthcare systems globally.