Multivariable linear regression of the association of mode of contraception and GDP (a measure of country's wealth) with prostate cancer (PCa) incidence and PCa mortality
| Estimate | 95% CI | p Value | |
| PCa incidence | |||
| Oral contraceptive use | 1.06 | 0.58 to 1.6 | <0.001 |
| Intrauterine device | 0.01 | −0.4 to 0.4 | 0.9 |
| Condom use | 0.9 | −0.1 to 1.9 | 0.3 |
| Vaginal barrier | 0.07 | −4 to 10 | 0.5 |
| GDP | 0.6 | 0.1 to 1.1 | 0.055 |
| PCa mortality | |||
| Oral contraceptive use | 0.75 | 0.31 to 1.1 | 0.06 |
| Intrauterine device | −0.02 | −0.4 to 3 | 0.2 |
| Condom use | 0.2 | −0.1 to 0.329 | 0.3 |
| Vaginal barrier | 0.01 | −2.1 to 2 | 0.9 |
| GDP | 0.16 | 0.04 to 0.9 | 0.09 |
GDP, gross domestic product per capita. GDP refers to the market value of all final goods and services produced in a country in a given period. GDP per capita is often considered an indicator of a country's standard of living.