Table 2.
Association of symptoms and disease labels with numbers of older and younger siblings (mutually adjusted)
| Older siblings (per additional sibling) adjusted for younger siblings | Younger siblings (per additional sibling) adjusted for older siblings | Comparison of trends for older and younger siblings | |||
|---|---|---|---|---|---|
| OR (95% CL) | P value | OR (95% CL) | P value | P value | |
| Symptom (6 to 7-year-olds) | |||||
| Wheeze ever | 0.97 (0.95, 0.98) | < 0.0001 | 0.96 (0.94, 0.98) | 0.0003 | 0.82 |
| Wheeze in last 12 months | 1.01 (0.99, 1.03) | 0.38 | 0.96 (0.93, 0.98) | 0.0008 | 0.001 |
| Severe wheeze in last 12 months | 1.07 (1.04, 1.10) | < 0.0001 | 1.04 (1.01, 1.08) | 0.02 | 0.25 |
| Asthma ever | 0.99 (0.97, 1.01) | 0.27 | 0.98 (0.96, 1.01) | 0.23 | 0.81 |
| Rhinitis ever | 0.93 (0.91, 0.94) | < 0.0001 | 1.03 (1.01, 1.05) | 0.006 | < 0.0001 |
| Rhinoconjunctivitis in last 12 months | 0.98 (0.96, 1.00) | 0.03 | 1.03 (1.00, 1.06) | 0.04 | 0.003 |
| Severe rhinoconjunctivitis | 1.00 (0.93, 1.07) | 0.89 | 1.11 (1.02, 1.21) | 0.01 | 0.05 |
| Hay fever ever | 0.91 (0.89, 0.93) | < 0.0001 | 1.00 (0.97, 1.02) | 0.74 | < 0.0001 |
| Itchy rash ever | 0.98 (0.96, 1.00) | 0.02 | 1.06 (1.04, 1.09) | < 0.0001 | < 0.0001 |
| Itchy flexural rash in last 12 months | 0.98 (0.96, 1.00) | 0.09 | 1.06 (1.03, 1.09) | < 0.0001 | < 0.0001 |
| Severe itchy flexural rash | 1.14 (1.08, 1.20) | < 0.0001 | 1.20 (1.12, 1.28) | < 0.0001 | 0.22 |
| Eczema ever | 0.90 (0.88, 0.92) | < 0.0001 | 1.03 (1.01, 1.06) | 0.02 | < 0.0001 |
| Symptom (13 to 14-year-olds) | |||||
| Wheeze ever | 0.97 (0.96, 0.99) | 0.0005 | 0.99 (0.97, 1.01) | 0.27 | 0.12 |
| Wheeze in last 12 months | 0.99 (0.97, 1.01) | 0.26 | 1.10 (0.99, 1.03) | 0.43 | 0.19 |
| Severe wheeze in last 12 months | 1.04 (1.02, 1.07) | 0.0001 | 1.07 (1.04, 1.09) | < 0.0001 | 0.13 |
| Asthma ever | 0.97 (0.96, 0.99) | 0.0003 | 0.99 (0.97, 1.01) | 0.36 | 0.09 |
| Rhinitis ever | 1.00 (0.98, 1.01) | 0.65 | 1.01 (0.99, 1.02) | 0.50 | 0.41 |
| Rhinoconjunctivitis in last 12 months | 1.00 (0.99, 1.02) | 0.71 | 1.03 (1.01, 1.05) | 0.004 | 0.05 |
| Severe rhinoconjunctivitis | 1.03 (0.99, 1.08) | 0.15 | 1.07 (1.02, 1.13) | 0.004 | 0.24 |
| Hay fever ever | 0.94 (0.93, 0.96) | < 0.0001 | 0.97 (0.96, 0.99) | 0.006 | 0.02 |
| Itchy rash ever | 1.02 (1.01, 1.04) | 0.06 | 1.02 (1.00, 1.04) | 0.03 | 0.81 |
| Itchy flexural rash in last 12 months | 1.03 (1.01, 1.05) | 0.01 | 1.03 (1.01, 1.06) | 0.004 | 0.66 |
| Severe itchy flexural rash | 1.12 (1.07, 1.16) | < 0.0001 | 1.10 (1.05, 1.14) | < 0.0001 | 0.55 |
| Eczema ever | 0.96 (0.95, 0.98) | < 0.0001 | 0.98 (0.96, 1.00) | 0.06 | 0.28 |
All analyses are adjusted for sex, region, language and national GNI per capita.