Table 3.
Univariate Rate Ratios for Association Between Neighborhood Socioeconomic Factors and Invasive Community-Associated Methicillin-Resistant Staphylococcus aureus Incidence
| Variable | Rate Ratioa | (95% Confidence Interval) | P Value |
|---|---|---|---|
| Low-income households | 19.65 | (14.78–26.12) | <.0001 |
| High-income households | 0.008 | (.003–.02) | <.0001 |
| Poverty | 16.78 | (11.92–23.62) | <.0001 |
| Income inequality index | 12.99 | (6.54–25.82) | <.0001 |
| Crowding | 437.72 | (173.16–1106.48) | <.0001 |
| Expensive homes | 0.46 | (.31–.68) | .0001 |
| Rural areas | 0.36 | (.25–.52) | <.0001 |
| Low education | 47.65 | (33.96–66.86) | <.0001 |
| High education | 0.11 | (.08–.14) | <.0001 |
| Health insurance | 0.08 | (.05–.11) | <.0001 |
| Medically underserved area | 2.40 | (2.16–2.68) | <.0001 |
aSocioeconomic status variables were coded as ranging from 0 (0% of the census tract with this characteristic) to 1 (100% of the census tract with this characteristic). As an example to assist in interpreting the rate ratios, the rate ratio of 19.65 for low income means that for each increase of 10% in households in a census tract with low income, we would predict an increase in the methicillin-resistant Staphylococcus aureus rate (cases/population) of 1.35-fold (the 10th root of 19.65).