Association between maternal age at menarche (categorical and continuous) and atopic outcomes
| Maternal age at menarche (years) | Doctor diagnosed asthma (20.4%) | Ever reported eczema (58.6%) | Ever reported hay fever (12.1%) | Atopy (SPT weal ⩾2 mm) (20.6%) |
|---|---|---|---|---|
| SPT, skin prick test. | ||||
| <12 | 309/1356 (22.8%) | 604/1051 (57.5%) | 146/1167 (12.5%) | 224/1098 (20.4%) |
| 12 | 284/1518 (18.7%) | 712/1194 (59.6%) | 167/1334 (12.5%) | 239/1223 (19.5%) |
| 13 | 429/2068 (20.7%) | 979/1640 (59.7%) | 206/1812 (11.4%) | 377/1726 (21.8%) |
| 14 | 230/1225 (18.8%) | 584/979 (59.7%) | 134/1071 (12.5%) | 187/999 (18.7%) |
| 15 | 116/591 (19.6%) | 264/451 (58.5%) | 70/509 (13.8%) | 94/487 (19.3%) |
| 16+ | 86/338 (25.4%) | 146/262 (55.7%) | 32/295 (10.8%) | 54/259 (20.8%) |
| χ2 (p value) | 15.00 (0.010) | 2.92 (0.713) | 3.15 (0.677) | 4.87 (0.432) |
| p for trend | 0.729 | 0.985 | 0.903 | 0.733 |
| Mean (SD) difference (years) | 0.042 (0.048) | 0.004 (0.041) | 0.018 (0.058) | 0.020 (0.063) |
| t (p value) | 0.86 (0.389) | 0.10 (0.918) | 0.30 (0.762) | 0.37 (0.709) |