Widening the scope for the burden of COVID-19 - Comorbidities and long COVID: an analysis of the three pandemic years in Luxembourg.

Abstract

Objective: Burden of disease studies evaluate the direct impact of disease in terms of morbidity and premature mortality over a given time horizon. The objective of this study was to estimate the burden of COVID-19 in Luxembourg during the first three years of the pandemic, with a particular focus on methodologies applied to two areas of high uncertainty: post-acute consequences (PAC) of COVID-19 and the disparity of associated pathologies to COVID-19 deaths compared to other causes of deaths.

Materials and methods: Epidemiological monitoring data on screening, hospital admission, and mortality associated with COVID-19 were used to estimate disability-adjusted life years (DALYs). Years of Life lost due to premature death (YLL) estimates have been adjusted for the impact of comorbidity profiles from cause-of-death data using the Charlson Comorbidity Index (CCI). In the absence of a PAC-specific disability weight, a symptom-based approach using data from a national cohort study was applied and compared with alternative weights used in the literature. A one-by-one sensitivity analysis was performed to evaluate the uncertainty associated with each model parameter.

Results: The total burden of COVID-19, including PAC, over three years, was estimated at 17,801 DALYs, combining 14,903 YLLs and 2,898 YLDs (Years of Healthy Life lived with Disability). Comorbidity adjustment led to an average reduction of 9% in YLL estimates. Alternative choices for PAC led to an up to 3-fold increase in YLD compared to our base case estimates. Prevalence, disability weight, and duration of PAC were the most influential parameters identified in the sensitivity analysis.

Conclusions: The COVID-19 pandemic has produced a significant burden on the resident population in Luxembourg. Adjusting for comorbidities is an important step in assessing the burden of COVID-19. The uncertainty associated with PAC parameters has highlighted the need for further research to standardize the definition of the prevalence, duration, and severity of this condition. The suggested symptom-based approach presents a flexible option until PAC-specific disability weights are derived in the future.