Adjusted odds ratios (95% CI)* for a high hygiene score according to perinatal, maternal, social, and environmental factors adjusted within and between groups
| Within group | Between groups | |||
|---|---|---|---|---|
| Group | Adjusted OR (95% CI) | p | Adjusted OR (95% CI) | p |
| *Adjusted OR (95% CI) are calculated comparing the top quintile of hygiene score versus the bottom 4 quintiles. | ||||
| Perinatal factors | ||||
| Maternal parity | ||||
| 0 | 1 | 0.0004 | NS | |
| 1 | 1.11 (0.9 to 1.2) | |||
| 2+ | 1.3 (1.15 to 1.5) | |||
| Duration of breast feeding | ||||
| Never | 1 | 0.0002 | NS | |
| <1 month | 0.9 (0.7 to 1.02) | |||
| 1–3 months | 0.9 (0.7 to 1.03) | |||
| 3–6 months | 0.8 (0.7 to 0.9) | |||
| >6 months | 0.7 (0.6 to 0.8) | |||
| Maternal factors | ||||
| Maternal smoking during pregnancy | ||||
| None | 1 | <0.0001 | 1 | <0.0001 |
| 1–9 per day | 1.25 (1.03 to 1.51) | 1.34 (1.09 to 1.66) | ||
| 10–19 per day | 1.63 (1.37 to 1.94) | 1.77 (1.44 to 2.18) | ||
| 20+ per day | 1.97 (1.51 to 2.57) | 2.18 (1.6 to 2.98) | ||
| Maternal highest educational qualification | ||||
| CSE | 1.61 (1.32 to 1.97) | <0.0001 | 1.3 (1.01 to 1.6) | 0.0003 |
| Vocational | 1.23 (0.9 to 1.53) | 1.02 (0.8 to 1.3) | ||
| O level | 1.24 (1.04 to 1.5) | 1.02 (0.8 to 1.2) | ||
| A level | 1.54 (1.28 to 1.83) | 1.3 (1.1 to 1.6) | ||
| Degree | 1 | 1 | ||
| Childcare by childminder/nursery (>10 hours per week) | ||||
| No | 1 | <0.0001 | 1 | <0.0001 |
| Yes | 0.67 (0.58 to 0.78) | 0.72 (0.62 to 0.85) | ||
| Maternal eczema | ||||
| No | 1 | 0.0007 | 1 | 0.004 |
| Yes | 0.81 (0.71 to 0.91) | 0.83 (0.73 to 0.94) | ||
| Social factors | ||||
| Housing tenure | ||||
| Local authority housing | 1.68 (1.44 to 1.97) | <0.0001 | 1.36 (1.14 to 1.62) | 0.003 |
| Private rented | 1.10 (0.91 to 1.32) | 1.01 (0.83 to 1.23) | ||
| Mortgaged/owned | 1 | 1 | ||
| Damp housing (8 months) | ||||
| No | 1 | 0.0004 | 1 | 0.001 |
| Yes | 0.82 (0.74 to 0.92) | 0.8 (0.7 to 0.9) | ||
| Environmental factors | ||||
| Weekly contact with pets | ||||
| Non-furry pets (v none) | 1.2 (1.01 to 1.4) | 0.03 | 1.2 (1.02 to 1.4) | 0.03 |
| Chemical exposure score: | ||||
| At 8 months | 1.07 (1.06 to 1.08) | <0.0001 | 1.07 (1.06 to 1.08) | <0.0001 |
| Month of questionnaire return (for hygiene score @ 15 months) | ||||
| October–March (winter) | 0.64 (0.58 to 0.71) | 0.63 (0.6 to 0.7) | <0.0001 | |
| April–September (summer) | 1 | <0.0001 | 1 | |