Table 4 Country-level confounding variables controlled for in two or more studies
Indicator | Number (%) of studies using as confounding variable |
|---|---|
GDP (or GNI) per capita (including squared term or growth rate) | 26 (76) |
Urbanization rate (or urban growth rate) | 10 (29) |
Population (total, density, or growth rate) | 7 (21) |
Educational attainment (years completed, enrollment rate, or literacy rate) | 6 (18) |
Income inequality | 4 (12) |
Female labor force participation rate | 3 (9) |
Health expenditure (% of GDP, total or public) | 3 (9) |
Average caloric intake | 2 (6) |
Consumer price index | 2 (6) |
Dependency ratio | 2 (6) |
FDI (total or % of GDP) | 2 (6) |
Fertility rate | 2 (6) |
Political rights/civil liberties index | 2 (6) |
Polity score | 2 (6) |
Immunization rate (any type) | 2 (6) |
Smoking prevalence | 2 (6) |
No confounders included/tested in models | 7 (21) |