Associations between COVID-19 mortality by country, latitude and % of population ≥65 years
| Variable | Regression coefficient | SE | P value | % of variation explained | Effect size (95% CI)* | |
| Univariate models | ||||||
| Latitude | 0.1090 | 0.0139 | <0.0005 | 18.4 | 11.5% (8.5% to 14.6%) | |
| %≥65 | 0.1766 | 0.0199 | <0.0005 | 40.4 | 19.3% (14.8% to 24.1%) | |
| Multivariate model | ||||||
| Latitude | 0.0478 | 0.0194 | 0.015 | 42.1 | 4.9% (1.0% to 9.0%) | |
| %≥65 | 0.1235 | 0.0291 | <0.0005 | 13.1% (6.9%19.8%) |
*The effect size is, for latitude, the percentage increase in mortality from one location, situated at least 28° north, to another location 1° further north and, for %≥65, the percentage increase in mortality for each one % increase in %≥65.