Determinants of post discharge mortality among hospitalized COVID-19 patients

Background & objectives: The post-acute effects of COVID-19 are continually being updated. This investigation was conducted to evaluate the determinants of post discharge mortality in hospitalized COVID-19 patients, especially 18-45 yr of age.

Methods: A series of three nested case-control analyses was conducted on follow up data collected in the National Clinical Registry for COVID-19 between September 2020 and February 2023 from 31 hospitals. Matching (1:4) was done by the date of hospital admission ±14 days for the following comparisons: (i) case-patients reported as dead vs. controls alive at any contact within one year follow up; (ii) the same in the 18-45 yr age group and (iii) case-patients reported as dead between the first and one year of follow up vs. controls alive at one year post discharge.

Results: The one year post discharge mortality was 6.5 per cent (n=942). Age [≤18 yr: adjusted odds ratio (aOR) (95% confidence interval [CI]): 1.7 (1.04, 2.9); 40-59 yr: aOR (95% CI): 2.6 (1.9, 3.6); ≥60 yr: aOR (95% CI): 4.2 (3.1, 5.7)], male gender [aOR (95% CI): 1.3 (1.1, 1.5)], moderate-to-severe COVID-19 [aOR (95% CI): 1.4 (1.2, 1.8)] and comorbidities [aOR (95%CI): 1.8 (1.4, 2.2)] were associated with higher odds of post-discharge one-year mortality, whereas 60 per cent protection was conferred by vaccination before the COVID-19 infection. The history of moderate-to-severe COVID-19 disease [aOR (95% CI): 2.3 (1.4, 3.8)] and any comorbidities [aOR (95% CI): 3 (1.9, 4.8)] were associated with post-discharge mortality in the 18-45-yr age bracket as well. Post COVID condition (PCC) was reported in 17.1 per cent of the participants. Death beyond the first follow up was associated with comorbidities [aOR (95%CI): 9.4 (3.4, 26.1)] and reported PCC [aOR (95% CI): 2.7 (1.2, 6)].

Interpretation & conclusions: Prior vaccination protects against post discharge mortality till one year in hospitalized COVID-19 patients. PCC may have long term deleterious effects, including mortality, for which further research is warranted.