Epidemiological Profile, Causes, and Trends of Mortality in the Emergency Department of a Tertiary Hospital in Northern India: A Five-Year Retrospective Study.

BACKGROUND: Emergency departments (EDs) in tertiary care hospitals serve as the primary interface for critically ill patients and are key indicators of health system performance. Mortality data from EDs provide actionable insights for quality improvement, resource allocation, and policy planning. OBJECTIVES: The objective of this study was to analyse patterns of emergency mortality at a tertiary care teaching hospital over five years (2021-2025) across temporal, demographic, diagnostic, and specialty-specific dimensions. METHODS: A retrospective analysis of 38,818 emergency admissions from January 2021 to December 2025 was performed. Medical records data coded with the International Classification of Diseases, Tenth Revision (ICD-10) were analysed after correction of coding errors and diagnostic reclassification. Statistical analyses included Kaplan-Meier survival analysis, chi-square tests, Mann-Whitney U and Kruskal-Wallis H tests, binary logistic regression, and the Standardized Mortality Ratio (SMR). RESULTS: A total of 7,318 deaths were recorded, for an overall crude mortality rate of 18.9%. Mortality declined from 26.2% in 2021 to 12.7% in 2025. Winter (23.6%), the dawn period (04:00-07:59 hours; 34.3%), and the night shift (27.3%) carried the highest mortality. Elderly patients aged 61+ years accounted for 3,879 (53.0%) deaths, at a 33.3% mortality rate. The circulatory system was the leading cause (1,954 deaths; 26.7%), while septicaemia (A41.9) was the single most common diagnosis (742 deaths). Increasing age was the strongest independent predictor of death (adjusted OR (aOR) 5.21, 95% CI 4.63-5.86). The SMR fell from 2.62 to 1.27 but remained above unity throughout. CONCLUSION: The ED demonstrates significant temporal, demographic, and diagnostic mortality patterning. The declining SMR reflects meaningful quality improvement, yet persistent excess mortality during winter, at night, and among the elderly identifies clear targets for system-level intervention.