TABLE 2—
Results of Multivariate Cox Proportional Hazard Regression Analyses (Hazard Ratios [HRs] and 95% Confidence Intervals [CIs]) Estimating Effects of Selected Characteristics on Completion of 4:3:1:3 Immunization Series: US National Immunization Survey, 2003
| Model 1, HR (95% CI) | Model 2, HR (95% CI) | Model 3, HR (95% CI) | Model 4, HR (95% CI) | Model 5, HR (95% CI) | Model 6, HR (95% CI) | |
| Child’s race/ethnicity | ||||||
| Non-Hispanic other/multiracial | 0.98 (0.88, 1.09) | 0.98 (0.81, 1.09) | 0.98 (0.88, 1.09) | 0.96 (0.86, 1.07) | 0.97 (0.87, 1.09) | 0.97 (0.87, 1.08) |
| Non-Hispanic Black | 0.84 (0.74, 0.95)** | 0.84 (0.74, 0.96)** | 0.84 (0.74, 0.96)** | 0.85 (0.75, 0.97)** | 0.89 (0.78, 1.02) | 0.89 (0.78, 1.02) |
| Hispanic | 1.11 (1.02, 1.21)** | 1.11 (1.02, 1.22)** | 1.10 (1.01, 1.21)* | 1.11 (1.01, 1.22)* | 1.12 (1.02, 1.23)* | 1.11 (1.01, 1.22)* |
| Non-Hispanic White (reference) | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| Mother’s age, y | ||||||
| ≤ 29 | 0.96 (0.90, 1.03) | 0.97 (0.90, 1.04) | 0.93 (0.86, 0.99)* | 0.95 (0.88, 1.02) | 0.95 (0.88, 1.03) | |
| 30 (reference) | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | |
| Mother’s educational level | ||||||
| Less than high school | 1.04 (0.91, 1.18) | 1.11 (0.97, 1.25) | 1.16 (1.02, 1.32)* | 1.16 (1.01, 1.33)* | ||
| High school | 0.86 (0.96, 1.04) | 0.99 (0.91, 1.07) | 1.02 (0.94, 1.11) | 1.03 (0.94, 1.12) | ||
| Some college | 0.99 (0.91, 1.08) | 1.02 (0.94, 1.11) | 1.04 (0.95, 1.13) | 1.05 (0.96, 1.14) | ||
| College (reference) | 1.00 | 1.00 | 1.00 | 1.00 | ||
| No. of children aged younger than 18 years | ||||||
| ≥ 4 | 0.69 (0.60, 0.79)*** | 0.68 (0.59, 0.77)*** | 0.68 (0.59, 0.78)*** | |||
| 2–3 | 0.86 (0.80, 0.92)*** | 0.85 (0.79, 0.91)*** | 0.85 (0.79, 0.91)*** | |||
| 1 (reference) | 1.00 | 1.00 | 1.00 | |||
| Mother’s marital status | ||||||
| Divorced/separated/widowed/ deceased | 0.84 (0.73, 0.96)** | 0.83 (0.73, 0.96)*** | ||||
| Never married | 0.86 (0.77, 0.97)** | 0.86 (0.76, 0.96)*** | ||||
| Married (reference) | 1.00 | 1.00 | ||||
| Income-to-poverty ratio | ||||||
| < 1 | 1.01 (0.89, 1.13) | |||||
| 1–1.99 | 0.97 (0.88, 1.08) | |||||
| 2–2.99 | 0.93 (0.85, 1.02) | |||||
| ≥ 3 (reference) | 1.00 | |||||
| Information reported from vaccination card (control variable) | ||||||
| No | 0.82 (0.76, 0.88)*** | 0.82 (0.76, 0.88)*** | 0.82 (0.76, 0.88)*** | 0.83 (0.77, 0.89)*** | 0.83 (0.78, 0.89)*** | 0.83 (0.78, 0.89)*** |
| Yes (reference) | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
Note. All variables included in the multivariate models were treated as time fixed (non–time dependent). A total of 9510 children completed the vaccination series.
* P < .05; **P < .01; ***P < .001.