Table 3 Definition of six epidemiological measures used to quantify COVID-19 attributable mortality. \({\varvec{O}}\) is the number of observable deaths and \({\varvec{E}}\) the number of expected deaths
Definition | Formula | Interpretation | Appropriate for comparison of attributable mortality |
|---|---|---|---|
Excess deaths (RD) | \(O-E\) | Total number of excess deaths | no |
Per capita rate of excess deaths (RDp.c.) | \((O-E)/n\times \mathrm{100,000}\) | Excess deaths per 100,000 inhabitants | no |
Standardized mortality ratio (SMR) | \(\frac{O}{E}\) | Ratio of observed to expected deaths | yes |
p-score | \(\frac{O-E}{E}\) | Proportion of deaths above the expected level | yes |
z-score | \(\frac{O-E}{sd(O)}\) | Number of standard deviations away from what is expected | no |
Population attributable fraction (PAF) | \(\frac{O-E}{O}\) | Proportion of attributable deaths | yes |