Table 1.
Association of symptoms and disease labels with total number of siblings, odds ratios by category and test for trend
| No siblings OR (95% CL) | One sibling (vs. none) OR (95% CL) | Two siblings (vs. none) OR (95% CL) | Three or more siblings (vs. none) OR (95% CL) | Trend P value | |
|---|---|---|---|---|---|
| Symptom (6 to 7-year-olds) | |||||
| Wheeze ever | 1.00 (reference) | 0.99 (0.95, 1.03) | 0.93 (0.89, 0.98) | 0.89 (0.84, 0.94) | < 0.0001 |
| Wheeze in last 12 months | 1.00 (reference) | 0.99 (0.94, 1.04) | 0.96 (0.91, 1.02) | 0.99 (0.92, 1.05) | 0.35 |
| Severe wheeze in last 12 months | 1.00 (reference) | 0.99 (0.92, 1.07) | 1.05 (0.97, 1.14) | 1.19 (1.09, 1.30) | < 0.0001 |
| Asthma ever | 1.00 (reference) | 1.02 (0.97, 1.08) | 0.95 (0.89, 1.01) | 0.98 (0.92, 1.05) | 0.11 |
| Rhinitis ever | 1.00 (reference) | 0.96 (0.92, 1.00) | 0.87 (0.83, 0.91) | 0.86 (0.82, 0.90) | < 0.0001 |
| Rhinoconjunctivitis in last 12 months | 1.00 (reference) | 1.00 (0.95, 1.06) | 0.95 (0.90, 1.01) | 0.96 (0.90, 1.04) | 0.09 |
| Severe rhinoconjunctivitis | 1.00 (reference) | 1.03 (0.86, 1.23) | 1.01 (0.83, 1.23) | 1.15 (0.92, 1.43) | 0.32 |
| Hay fever ever | 1.00 (reference) | 0.97 (0.91, 1.02) | 0.85 (0.79, 0.90) | 0.81 (0.75, 0.87) | < 0.0001 |
| Itchy rash ever | 1.00 (reference) | 1.04 (1.00, 1.09) | 1.00 (0.95, 1.05) | 1.02 (0.96, 1.08) | 0.82 |
| Itchy flexural rash in last 12 months | 1.00 (reference) | 1.09 (1.03, 1.15) | 1.01 (0.95, 1.08) | 1.04 (0.97, 1.12) | 0.91 |
| Severe itchy flexural rash | 1.00 (reference) | 1.04 (0.89, 1.22) | 1.14 (0.96, 1.35) | 1.63 (1.36, 1.95) | < 0.0001 |
| Eczema ever | 1.00 (reference) | 1.03 (0.98, 1.08) | 0.92 (0.87, 0.97) | 0.81 (0.75, 0.86) | < 0.0001 |
| Symptom (13 to 14-year-olds) | |||||
| Wheeze ever | 1.00 (reference) | 0.94 (0.89, 0.99) | 0.92 (0.87, 0.98) | 0.90 (0.85, 0.96) | 0.002 |
| Wheeze in last 12 months | 1.00 (reference) | 0.96 (0.90, 1.03) | 0.98 (0.92, 1.05) | 0.97 (0.91, 1.04) | 0.82 |
| Severe wheeze in last 12 months | 1.00 (reference) | 0.96 (0.88, 1.03) | 1.05 (0.97, 1.14) | 1.14 (1.05, 1.24) | < 0.0001 |
| Asthma ever | 1.00 (reference) | 0.96 (0.91, 1.02) | 0.94 (0.89, 1.00) | 0.91 (0.85, 0.96) | 0.006 |
| Rhinitis ever | 1.00 (reference) | 0.96 (0.91, 1.00) | 0.94 (0.89, 0.99) | 0.97 (0.92, 1.02) | 0.58 |
| Rhinoconjunctivitis in last 12 months | 1.00 (reference) | 0.97 (0.91, 1.03) | 0.96 (0.90, 1.02) | 1.03 (0.96, 1.09) | 0.12 |
| Severe rhinoconjunctivitis | 1.00 (reference) | 0.93 (0.78, 1.11) | 0.89 (0.75, 1.07) | 1.09 (0.91, 1.30) | 0.07 |
| Hay fever ever | 1.00 (reference) | 0.92 (0.86, 0.97) | 0.86 (0.81, 0.91) | 0.82 (0.77, 0.88) | < 0.0001 |
| Itchy rash ever | 1.00 (reference) | 0.93 (0.88, 0.99) | 0.94 (0.89, 1.00) | 1.03 (0.97, 1.10) | 0.009 |
| Itchy flexural rash in last 12 months | 1.00 (reference) | 0.91 (0.85, 0.98) | 0.96 (0.88, 1.03) | 1.05 (0.97, 1.13) | 0.001 |
| Severe itchy flexural rash | 1.00 (reference) | 0.96 (0.81, 1.15) | 1.09 (0.91, 1.30) | 1.33 (1.11, 1.58) | < 0.0001 |
| Eczema ever | 1.00 (reference) | 0.95 (0.89, 1.01) | 0.90 (0.84, 0.96) | 0.88 (0.82, 0.94) | < 0.0001 |
All analyses are adjusted for gender, region, language and national GNI per capita.