Outcome | Number of participants (studies) | Relative effect (95% CI) | Certainty |
Prevalence: as a proxy for risk of infection | 83 294 (21 observational studies) | PP: 9.38% (7.38 to 11.38) | ⨁◯◯◯ Very low* |
Mortality | 62 521 (15 observational studies) | OR: 0.9 (0.72 to 1.13) | ⨁◯◯◯ Very low† |
Hospitalisation | 25 065 (9 observational studies) | OR: 0.95 (0.71 to 1.26) | ⨁◯◯◯ Very low‡ |
ICU admission | 13 092 (9 observational studies) | OR: 0.96 (0.75 to 1.24) | ⨁◯◯◯ Very low§ |
*Downgraded two levels due to unexplained statistical heterogeneity, one level due to possible publication bias (skewed funnel plot).
†Downgraded one level due to unexplained statistical heterogeneity, downgraded one level due to imprecision (wide CIs).
‡Downgraded two levels due to unexplained statistical heterogeneity, downgraded one level due to imprecision (wide CIs).
§Downgraded one level due to imprecision (wide CIs).
ICU, intensive care unit; PP, pooled prevalence.