Is older age associated with COVID-19 mortality in the absence of other risk factors? General population cohort study of 470,034 participants
Frederick K. Ho, Fanny Petermann‐Rocha, Stuart R. Gray, Bhautesh Jani, Srinivasa Vittal Katikireddi, Claire L. Niedzwiedz, Hamish Foster, Claire E. Hastie, Daniel Mackay, Jason M. R. Gill, Catherine O’Donnell, Paul Welsh, Frances S Mair, Naveed Sattar, Carlos Celis‐Morales, Jill P. Pell
Abstract
INTRODUCTION: Older people have been reported to be at higher risk of COVID-19 mortality. This study explored the factors mediating this association and whether older age was associated with increased mortality risk in the absence of other risk factors. METHODS: In UK Biobank, a population cohort study, baseline data were linked to COVID-19 deaths. Poisson regression was used to study the association between current age and COVID-19 mortality. RESULTS: Among eligible participants, 438 (0.09%) died of COVID-19. Current age was associated exponentially with COVID-19 mortality. Overall, participants aged ≥75 years were at 13-fold (95% CI 9.13-17.85) mortality risk compared with those <65 years. Low forced expiratory volume in 1 second, high systolic blood pressure, low handgrip strength, and multiple long-term conditions were significant mediators, and collectively explained 39.3% of their excess risk. The associations between these risk factors and COVID-19 mortality were stronger among older participants. Participants aged ≥75 without additional risk factors were at 4-fold risk (95% CI 1.57-9.96, P = 0.004) compared with all participants aged <65 years. CONCLUSIONS: Higher COVID-19 mortality among older adults was partially explained by other risk factors. 'Healthy' older adults were at much lower risk. Nonetheless, older age was an independent risk factor for COVID-19 mortality.