Table 4.
Odds Ratios of Caesarean Section (95% Confidence Intervals) Given by Other Covariates in Jiangsu and Inner Mongolia and in Their Comparison
| Odds Ratio for Jiangsu | Odds Ratio for Inner Mongolia | Odds Ratio in comparison | |
|---|---|---|---|
| Maternal ethnicity | |||
| Han | Reference | Reference | Reference |
| Minority | 0.650 (0.477, 0.866)** | 1.251 (1.190, 1.315)*** | 1.272 (1.211,1.335)*** |
| Maternal age (year) | |||
| <20 | Reference | Reference | Reference |
| 20–24 | 2.868 (0.860, 17.833) | 1.294 (0.950, 1.794) | 1.357 (1.005, 1.864)* |
| 25–29 | 2.847 (0.863, 17.624) | 1.585 (1.170, 2.187)** | 1.582 (1.177, 2.165)** |
| 30–34 | 3.427 (1.036, 21.232)* | 2.250 (1.658, 3.108)*** | 2.220 (1.649, 3.041)*** |
| ≥35 | 5.273 (1.585, 32.747)* | 3.136 (2.301, 4.348)*** | 3.162 (2.341, 4.346)*** |
| Insurance coverage | |||
| Not insured | Reference | Reference | Reference |
| UHIS | 0.706 (0.628, 0.793)*** | 2.140 (1.882, 2.434)*** | 0.942 (0.865, 1.026) |
| NCMS |  |
1.203 (1.147, 1.263)*** | 1.124 (1.073, 1.178)*** |
| Infant weight (g) | |||
| <2500 | Reference | Reference | Reference |
| 2500–4000 | 0.425 (0.355, 0.512)*** | 0.926 (0.842, 1.018) | 0.742 (0.682, 0.808)*** |
| >4000 | 0.645 (0.499, 0.834)*** | 1.203 (1.147, 1.263)*** | 1.223 (1.104, 1.354)*** |
| Infant gender | |||
| Male | Reference | Reference | Reference |
| Female | 1.015 (0.909, 1.134) | 1.081 (1.036, 1.129)*** | 1.078 (1.036, 1.122)*** |
| Reproductive history | |||
| First-time mother | Reference | Reference | Reference |
| Others | 4.788 (4.164, 5.511)*** | 1.011 (0.974, 1.069) | 1.255 (1.192, 1.322)*** |
Notes: *5% significance; **1% significance; ***0.1% significance; 
no returned odds ratio due to the absence of data in this category.
Abbreviations: UHIS, Urban Health Insurance Schemes; NCMS, New Rural Cooperative Medical Scheme.