Variables | Model I | Model II | Model III | Model IV |
---|---|---|---|---|
OR (95% CI) | AOR (95% CI) | AOR (95% CI) | AOR (95% CI) | |
Maternal socio-economic variables | ||||
 Education | ||||
  None |  | 1.00 |  | 1.00 |
  Primary |  | 2.17(1.93–2.44)* |  | 2.18(1.94–2.45)* |
  Secondary |  | 3.28(2.83–3.79)* |  | 3.37(2.92–3.91)* |
  Higher |  | 7.22(4.85–10.75)* |  | 7.29(4.89–10.86)* |
 Occupation | ||||
  Not working |  | 1.00 |  | 1.00 |
  Professional/services |  | 1.52(1.20–1.93)* |  | 1.50(1.18–1.90)* |
  Sales |  | 1.29(1.16–1.44)* |  | 1.25(1.12–1.40)* |
  Agriculture/manual |  | 1.28(1.14–1.45)* |  | 1.24(1.10–1.41)* |
 Household wealth index | ||||
  Poorest |  | 1.00 |  | 1.00 |
  Poorer |  | 1.82(1.62–2.05)* |  | 1.83(1.63–2.06)* |
  Middle |  | 3.25(2.85–3.72)* |  | 3.26(2.85–3.72)* |
  Richer |  | 5.72(4.84–6.76)* |  | 5.74(4.85–6.78)* |
  Richest |  | 7.66(6.01–9.75)* |  | 7.68(6.04–9.78)* |
 Type of residence | ||||
  Urban |  | 1.00 |  | 1.00 |
  Rural |  | 0.58(0.52–0.66)* |  | 0.59(0.52–0.67)* |
 Geo-political region | ||||
  Northcentral |  | 0.83(0.68–1.02) |  | 0.84(0.69–1.03) |
  North east |  | 0.65(0.54–0.80)* |  | 0.66(0.54–0.81)* |
  Northwest |  | 0.57(0.47–0.69)* |  | 0.57(0.47–0.69)* |
  Southeast |  | 1.00(0.77–1.31) |  | 0.99(0.76–1.30) |
  South-south |  | 0.39(0.32–0.48)* |  | 0.39(0.32–0.48)* |
  Southwest |  | 1.00 |  | 1.00 |
Bio-demographic variables | ||||
 Maternal age at child’s birth | ||||
  <  20 years |  |  | 1.00 | 1.00 |
  20–34 years |  |  | 2.93(2.40–3.57)* | 1.13(0.90–1.43) |
  > = 35 years |  |  | 3.86(3.11–4.79)* | 1.31(1.02–1.68)* |
 Marital status | ||||
  Not currently married |  |  | 1.00 | 1.00 |
  Currently married |  |  | 0.69(0.57–0.85)* | 0.95(0.75–1.20) |
 Child’s birth order | ||||
  2 |  |  | 1.00 | 1.00 |
  3 |  |  | 0.80(0.70–0.90)* | 0.98(0.84–1.15) |
  4+ |  |  | 0.54(0.49–0.60)* | 1.03(0.90–1.18) |
 Child’s birth interval | ||||
  < 24 months |  |  | 1.00 | 1.00 |
  24–36 months |  |  | 0.91(0.82–1.00) | 1.02(0.91–1.15) |
  > 36 months |  |  | 1.05(0.95–1.17) | 1.14(1.01–1.29)* |
 Survival status of preceding birth | ||||
  Dead | 0.64(0.57–0.71)* | 0.98 (0.87–1.12) | 0.67(0.61–0.75)* | 1.00(0.88–1.14) |
  Alive | 1.00 | 1.00 | 1.00 | 1.00 |
 Model parameters | ||||
  Log likelihood | − 11,422.43 | − 8404.44 | −11,243.46 | − 8389.31 |
  p value (Wald statistic) | < 0.001 | < 0.001 | < 0.001 | < 0.001 |