Quantification of the association between predisposing health conditions, demographic, and behavioural factors with hospitalisation, intensive care unit admission, and death from COVID-19: a systematic review and meta-analysis

Fernandez Villalobos, N. V.; Ott, J. J.; Klett-Tammen, C. J.; Bockey, A.; Vanella, P.; Krause, G.; Lange, B.

Background Comprehensive evidence synthesis on the associations between comorbidities and behavioural factors with hospitalisation, Intensive Care Unit (ICU) admission, and death due to COVID-19 is lacking leading to inconsistent national and international recommendations on who should be targeted for non-pharmaceutical interventions and vaccination strategies. Methods We performed a systematic review and meta-analysis on studies and publicly available data to quantify the association between predisposing health conditions, demographics, and behavioural factors with hospitalisation, ICU admission, and death from COVID-19. We provided ranges of reported and calculated effect estimates and pooled relative risks derived from a meta-analysis and meta-regression. Results 75 studies were included into qualitative and 74 into quantitative synthesis, with study populations ranging from 19 - 44,672 COVID-19 cases. The risk of dying from COVID-19 was significantly associated with cerebrovascular [pooled RR 2.7 (95% CI 1.7-4.1)] and cardiovascular [RR 3.2 (CI 2.3-4.5)] diseases, hypertension [RR 2.6 (CI 2.0-3.4)], and renal disease [RR 2.5 (CI 1.8-3.4)]. Health care workers had lower risk for death and severe outcomes of disease (RR 0.1 (CI 0.1-0.3). Our meta-regression showed a decrease of the effect of some comorbidities on severity of disease with higher median age of study populations. Associations between comorbidities and hospitalisation and ICU admission were less strong than for death. Conclusions We obtained robust estimates on the magnitude of risk for COVID-19 hospitalisation, ICU admission, and death associated with comorbidities, demographic, and behavioural risk factors. We identified and confirmed population groups that are vulnerable and that require targeted prevention approaches.