Table 3

Association between influenza vaccination and hospitalisation or all-cause mortality, and all-cause mortality alone, in people with COVID-19 within the CHIA database cohort (n=6921)

OutcomeModel specificationOR (95% CI)P value
Hospitalisation or all-cause mortalityUnadjusted1.39 (1.26 to 1.53)<0.001
Stabilised IPTW*0.85 (0.75 to 0.97)0.020
Stratification and pooling0.87 (0.78 to 0.98)0.021
All-cause mortalityUnadjusted1.13 (0.98 to 1.30)0.097
Stabilised IPTW†0.76 (0.64 to 0.90)0.001
Stratification and pooling0.59 (0.51 to 0.69)<0.001
  • *IPTW: inverse probability of treatment weighting based on the propensity score for influenza vaccination stabilised by the marginal probability of vaccination in the study population.

  • †The propensity score was divided into deciles, and the OR for the association between influenza vaccination and the outcome was estimated in each of the deciles. Mantel-Haenszel-weighted pooled OR was estimated using Woolf approximation for the calculation of SE.

  • CHIA, Care and Health Information Analytics.