Table 2. Association of ZIP code characteristics with the percent of residents aged 5 years and older that are vaccinated for COVID-19 and/or have had a COVID-19 booster shot.
| a) Percent vaccinated | ||||||||
| Bivariate | Multivariable | |||||||
| OLS regression models | (1) | (2) | (3) | (4) | ||||
| beta (95% CI) | p-value | beta (95% CI) | p-value | beta (95% CI) | p-value | beta (95% CI) | p-value | |
| Median household income ($10k increase) | 4.5*** (3.8,5.2) | <0.001 | 4.8*** (3.3,6.3) | <0.001 | 1.5 (−0.1,3.1) | 0.060 | 1.5 (−0.1,3.1) | 0.059 |
| Percent college graduates (10% point increase) | 2.9*** (2.2,3.6) | <0.001 | 2.3*** (1.1,3.6) | <0.001 | 5.1*** (3.9,6.3) | <0.001 | 5.1*** (3.9,6.3) | <0.001 |
| Percent Black, Latino, Indigenous (10% point increase) | −0.8** (−1.3,−0.3) | 0.002 | 1.4*** (0.8,2.0) | <0.001 | 1.8*** (1.1,2.6) | <0.001 | 1.9*** (1.0,2.8) | <0.001 |
| Percent essential worker (10% point increase) | −5.5*** (−7.3,−3.8) | <0.001 | 4.5*** (2.1,6.8) | <0.001 | 4.8*** (2.6,7.1) | <0.001 | 4.8*** (2.6,7.1) | <0.001 |
| VEI community (0,1) | −4.0** (−6.4,−1.6) | 0.001 | −0.3 (−3.6,3.0) | 0.850 | ||||
| Adjusted for age distribution | No | No | Yes | Yes | ||||
| R2 | NA | 0.38 | 0.47 | 0.47 | ||||
| b) Percent with a booster shot (dependent variable) | ||||||||
| Bivariate | Multivariable | |||||||
| OLS regression models | (1) | (2) | (3) | (4) | ||||
| beta (95% CI) | p-value | beta (95% CI) | p-value | beta (95% CI) | p-value | beta (95% CI) | p-value | |
| Median household income ($10k increase) | 6.8*** (6.2,7.4) | <0.001 | 3.7*** (2.2,5.2) | <0.001 | 0.6 (−0.8,2.0) | 0.392 | 0.6 (−0.7,1.9) | 0.351 |
| Percent college graduates (10% point increase) | 5.1*** (4.5,5.6) | <0.001 | 2.8*** (1.6,4.1) | <0.001 | 5.5*** (4.5,6.4) | <0.001 | 5.4*** (4.5,6.4) | <0.001 |
| Percent Black, Latino, Indigenous (10% point increase) | −2.6*** (−3.0,−2.2) | <0.001 | −0.1 (−0.4,0.3) | 0.687 | 0.8*** (0.4,1.2) | <0.001 | 1.0*** (0.5,1.5) | <0.001 |
| Percent essential worker (10% point increase) | −11.0*** (−12.4,−9.6) | <0.001 | 0.2 (−1.7,2.2) | 0.801 | 0.3 (−1.3,1.9) | 0.714 | 0.4 (−1.2,1.9) | 0.630 |
| VEI community (0,1) | −11.1*** (−13.4,−8.8) | <0.001 | −2.1 (−4.4,0.2) | 0.079 | ||||
| Adjusted for age distribution | No | No | Yes | Yes | ||||
| R2 | NA | 0.67 | 0.76 | 0.76 | ||||
Note: N = 418 ZIP codes. In column (1), each cell shows the result of a separate bivariate OLS regression model. In columns (2)–(4), each column shows the results of multivariable (adjusted) OLS regression models. Coefficients are scaled so that they can be interpreted as the percentage point change in primary series (or booster) coverage associated with a 10% (or $10K) increase in the continuous covariates. 95% CIs based on heteroskedasticity-robust standard errors are shown in parentheses. We adjusted for age by including variables denoting the percentage of ZIP code residents in the following age groups: 5–19, 20–39, 40–64, and 65+ years.
*p < 0.05,
**p < 0.01,
***p < 0.001.
CI, confidence interval; OLS, ordinary least squares; VEI, Vaccine Equity Initiative.