Importance of Identifying Excess Mortality Patterns Among Veterans

According to a recent study published online in the International Journal of Epidemiology, individual level data helped provide clinical updates into excess mortality patterns among veterans during the COVID-19 outbreak.

This study aimed to examine excess mortality during the COVID-19 pandemic using individual-level data from the Department of Veterans Affairs (VA) health care system in the US. While most previous analyses used aggregated data, this approach allowed for a more detailed understanding of the impact of the pandemic on patients.

“To improve understanding of the drivers of excess deaths during the COVID-19 pandemic, including those caused directly by the virus and those indirectly caused by pandemic disruptions, it is necessary to consider detailed individual-level characteristics,” wrote researchers.

The observational cohort study included patients under VA care between March 1, 2018, and February 28, 2022. Excess mortality was assessed on both an absolute and relative scale. Absolute measures included excess mortality rates and the number of excess deaths, while the relative scale focused on hazard ratios (HR) for mortality when comparing pandemic and pre-pandemic periods, considering different demographic and clinical subgroups. Comorbidity and frailty were quantified using the Charlson Comorbidity Index and Veterans Aging Cohort Study Index, respectively.

The study encompassed 5,905,747 patients, primarily men with a median age of 65.8 years. Overall, the excess mortality rate was 10.0 deaths per 1000 person-years (PY), resulting in a total of 103,164 excess deaths. The pandemic hazard ratio was 1.25 (with a 95% confidence interval of 1.25-1.26), signifying a heightened risk during the pandemic period.

The highest excess mortality rates were observed among the frailest patients (52.0/1000 PY) and those with the most significant comorbidity burden (16.3/1000 PY). Notably, the largest relative increases in mortality were found in the least frail patients, with an HR of 1.31, and in those with the lowest comorbidity burden, with an HR of 1.44.

In conclusion, this study's use of individual-level data provided valuable clinical and operational insights into excess mortality patterns during the COVID-19 pandemic in the United States. It highlighted the importance of reporting excess mortality in both absolute and relative terms to guide resource allocation during future outbreaks.

The findings underscored distinct differences in mortality risk among various clinical risk groups, emphasizing the need for a nuanced approach to pandemic response and preparedness.

Reference:

Weinberger DM, Bhaskaran K, Korves C, et al. Excess mortality in US Veterans during the COVID-19 pandemic: an individual-level cohort study [published online ahead of print, 2023 Oct 6]. Int J Epidemiol. 2023;dyad136. doi:10.1093/ije/dyad136