Table 2.
Multilevel growth curve models of body mass index and associations with the number of years since childbirth, green space quantity and quality, adjusted for confounding
| Model 1 | Model 2 | Model 3 | Model 4 | |
| Fixed part | Coefficient (SE) | |||
| Intercept | 25.976 (0.190) | 26.588 (0.308) | 26.004 (0.196) | 26.610 (0.318) |
| Years since childbirth (mean centred) | 0.444 (0.039) | 0.442 (0.039) | 0.448 (0.039) | 0.442 (0.039) |
| Years since childbirth2 | 0.012 (0.004) | 0.012 (0.004) | 0.008 (0.004) | 0.012 (0.004) |
| Years since childbirth3 | −0.006 (0.002) | −0.006 (0.002) | −0.007 (0.002) | −0.006 (0.002) |
| Mother’s age (mean centred) | −0.020 (0.018) | −0.019 (0.018) | −0.020 (0.018) | −0.019 (0.018) |
| Indigenous status (ref: no) | ||||
| Yes | 2.726 (0.694) | 2.775 (0.694) | 2.726 (0.694) | 2.782 (0.693) |
| Highest qualification (ref: postgraduate) | ||||
| Undergraduate | 0.198 (0.119) | 0.197 (0.119) | 0.197 (0.119) | 0.197 (0.119) |
| Year 11–13 | 0.062 (0.159) | 0.061 (0.159) | 0.064 (0.159) | 0.060 (0.159) |
| ≤Year 10 | 0.068 (0.197) | 0.064 (0.197) | 0.068 (0.197) | 0.066 (0.197) |
| Other | −0.460 (2.055) | −0.414 (2.055) | −0.449 (2.055) | −0.432 (2.056) |
| Economic status (ref: employed) | ||||
| Economically inactive | 0.166 (0.052) | 0.166 (0.052) | 0.165 (0.052) | 0.165 (0.052) |
| Unemployed | −0.065 (0.120) | −0.065 (0.120) | −0.065 (0.120) | −0.067 (0.120) |
| Area disadvantage (ref: affluent) | ||||
| Average | 0.023 (0.066) | 0.020 (0.066) | 0.021 (0.066) | 0.020 (0.066) |
| Disadvantaged | −0.023 (0.084) | −0.030 (0.084) | −0.025 (0.084) | −0.031 (0.084) |
| Remoteness (ref: major cities) | ||||
| Inner regional | 0.278 (0.274) | 0.127 (0.280) | 0.275 (0.274) | 0.129 (0.280) |
| Outer regional or remote | 1.041 (0.323) | 0.888 (0.328) | 1.038 (0.323) | 0.890 (0.328) |
| New birth (ref: no) | ||||
| Yes | 0.158 (0.068) | 0.158 (0.068) | 0.161 (0.068) | 0.159 (0.068) |
| Sibling(s) present (ref: no) | ||||
| Yes | −0.193 (0.092) | −0.194 (0.092) | −0.190 (0.092) | −0.197 (0.092) |
| Green space quantity (ref: <5%) | ||||
| 6%–10% | −0.425 (0.368) | |||
| 11%–20% | −0.688 (0.317) | |||
| 21%–40% | −0.857 (0.330) | |||
| ≥41% | −0.797 (0.406) | |||
| Good quality parks (ref: do not agree) | ||||
| Agree | 0.126 (0.103) | |||
| Strongly agree | −0.028 (0.055) | |||
| Green space quantity × good quality parks (ref: <5%) | ||||
| ≤5% × agree | −0.026 (0.103) | |||
| 6%–10% × disagree | −0.561 (0.392) | |||
| 6%–10% × agree | −0.417 (0.377) | |||
| 11%–20% × disagree | −0.696 (0.338) | |||
| 11%–20% × agree | −0.709 (0.327) | |||
| 21%–40% × disagree | −0.910 (0.353) | |||
| 21%–40% × agree | −0.870 (0.339) | |||
| ≥41% × disagree | −0.588 (0.431) | |||
| ≥41% × agree | −0.873 (0.414) | |||
| Random part | Variance (SE) | |||
| Level 3: area (SA2) | 2.010 (0.392) | 1.892 (0.384) | 2.006 (0.393) | 1.898 (0.384) |
| Level 2: mother | 26.969 (0.688) | 26.988 (0.688) | 26.964 (0.688) | 26.975 (0.688) |
| Level 1: time | 3.952 (0.045) | 3.952 (0.045) | 3.951 (0.045) | 3.951 (0.045) |
| −2*log likelihood | 94 605.73 | 94 597.52 | 94 602.97 | 94 592.90 |
SA2, Statistical Area 2.