Table 2.
Univariate and Multivariate Logistic Regression Analysis of Determinants of Seropositivity at Enrollment
| Determinants | Univariate Analysis | Multivariate Analysis | ||
|---|---|---|---|---|
| OR (95% CI) | P Value | aOR (95% CI) | P Value | |
| Age at enrollment, y | .97 (.92–1.02) | .194 | … | |
| Sex (male vs female) | .9 (.7–1.1) | .311 | … | |
| Age at the first dose of routine MMR vaccination | … | |||
| ≤15 mo (baseline) | 1.00 | 1.00 | ||
| 16–23 mo | 1.21 (.89–1.65) | .225 | 1.17 (.86–1.60) | .319 |
| ≥24 mo | 2.22 (1.55–3.18) | < .0001 | 1.49 (.95–2.32) | .080 |
| Age, y, at the second dose of routine MMR vaccine | 1.05 (1.02–1.09) | .005 | 1.01 (.94–1.09) | .753 |
| Time, mo, from the first to second dose of MMR vaccine | 1.00 (.99–1.00) | .019 | .99 (.99–1.00) | .014 |
| Time, mo, from the first dose of MMR vaccine to antibody titer evaluation | .99 (.98–.99) | < .0001 | a | |
| Time, mo, from the second dose of MMR vaccine to antibody titer evaluation | .99 (.98–.99) | < .0001 | .99 (.98–.99) | < .0001 |
Abbreviations: aOR, adjusted odds ratio; CI, confidence interval; MMR, measles-mumps-rubella; OR, odds ratio.
aOmitted because of collinearity; Hosmer–Lemeshow χ 2 = 5.1 (P = .747).