Variables | Model 0 | Model I cOR (95 % CI) | Model II aOR (95 % CI) |
---|---|---|---|
Fixed effects | |||
 Age at first childbirth | |||
 < 20 years |  | 1.16***[1.13–1.19] | 1.10** (1.07–1.12) |
 ≥ 20 years |  | Reference | Reference |
 Random effects | |||
 Primary sampling unit variance (95 % CI) | 0.11 (0.09–0.15) | 0.11 (0.08–0.14) | 0.06 (0.05–0.08) |
 Intraclass correlation coefficient | 0.03 | 0.03 | 0.02 |
 Wald chi-square | Reference | 170.27*** | 1430.54*** |
 Model fitness | |||
  Log-likelihood | -189072.57 | -188907.15 | -137588.17 |
  Akaike’s Information Criterion | 378149.1 | 377820.3 | 275226.3 |
  Sample size | 311,603 | 311,603 | 311,603 |
  Number of clusters | 1610 | 1610 | 1610 |