Risk of severe neonatal morbidity and neonatal mortality (SNMM) arising in the index birth admission and up to 27 days thereafter, comparing newborns born to immigrant and nonimmigrant females*
| Exposure group | No. with SNMM (rate per 1000 live births) | Unadjusted RR (95% CI)† | Adjusted RR (95% CI)†‡ | Adjusted absolute risk difference per 1000 live births (95% CI)†‡ |
|---|---|---|---|---|
| Nonimmigrants (n = 266 191) | 17 457 (65.6) | 1.00 (Ref.) | 1.00 (Ref.) | 0.0 (Ref.) |
| Immigrants (n = 148 050) | 7352 (49.7) | 0.76 (0.74 to 0.78) | 0.76 (0.74 to 0.79) | −15.2 (−16.6 to −13.8) |
Note: CI = confidence interval, Ref. = reference category, RR = relative risk.
↵* Data are limited to births to females who resided in an urban neighbourhood of the lowest income quintile and who had a singleton, in-hospital live birth at 20–42 weeks’ gestation in Ontario, Canada, from 2002 to 2019. Immigrant group excludes refugee immigrants.
↵† Using modified Poisson regression with a robust error variance. Generalized estimating equations with an exchangeable correlation structure accounted for correlated errors of potentially more than 1 birth clustered within the same mother.
↵‡ Adjusted for maternal age (15–19 yr, 20–29 yr, 30–39 yr, 40–50 yr), parity (0, 1, 2, ≥ 3) and any structural congenital anomaly (yes or no).