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 | 0.1074 | 0.0142 | <0.0005 | 33.1 | 11.3% (8.3% to 14.5%) | |
| %≥65 | 0.1766 | 0.0199 | <0.0005 | 40.4 | 19.3% (14.8% to 24.1%) | |
| Multivariate model | ||||||
| Latitude | 0.0428 | 0.0196 | 0.031 | 43.0 | 4.4% (0.4% to 8.5%) | |
| %≥65 | 0.1281 | 0.0291 | <0.0005 | 13.7% (7.4% to 20.3%) |
*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.