Table 3.
Regression analysis identifying factors associated with preterm mortality in Hubei Province, China (2001 – 2012)
| Covariates | Univariate analysis OR (95 % CI) |
Multivariable analysis* OR (95 % CI) |
|---|---|---|
| Year | 1.00 (1.00 -1.01) | ---- |
| Maternal age (<35 y vs. ≥ 35 y) | 1. 32 (1. 22–1.51) | ---- |
| Gestational week (<34 week vs. ≥ 34 week) | 2.76 ( 1.92 -2.99) | 1.01 (1.00-1.02) |
| Birth weight (<2.5 kg vs. ≥ 2.5 kg) | 1.07 ( 1.02 - 1.11) | 1.02 (1.00-1.03) |
| Pregnancy parity (1 vs. ≥ 2) | 1.08 (1.08 -1.11) | ---- |
| Birth parity (1 vs. ≥ 2) | 1.00 (1.00 - 1.01) | ---- |
| Assisted reproductive technology (yes vs. no) |
1.13 (1.09-1.15) | ---- |
| Income (<500 USD/month vs. ≥ 500 USD/month) | 1.31 (1.27 -1.39) | 1.12 (1.01-1.22) |
| Education (>9 years vs. ≤ 9 years) | 0.71 (0. 49–0. 89) | ---- |
| Residence (rural vs. urban) | 1.14 ( 1.10 - 1.29) | ---- |
| Newborn Emergency Transport Service (yes vs. no) | 2. 14 (2.00 - 3.02) | 0.81 (0.77-0.99) |
| Infant gender (female vs. male) | 0.67 ( 0.51 - 0.74) | ---- |
| Occupation (physical labor vs. office job) | 1.18 (1.10 -1.23) | ---- |
| Single birth | 0.97 (0.95 - 0.99) | ---- |
*Multivariate logistic model was fit with all characteristics considered as predictors of preterm mortality, and a backward-selection procedure was used to select significant variables included in the final model, with a P value < 0.05 indicating significance