Table 1.
Characteristics of study population
| Variables | Participants in 4 clusters | Excluded in LCA | P value |
|---|---|---|---|
| Number | 235/2491 (9.4%) | 2256/2491 (90.6%) | |
| Male | 149/235 (63.4%) | 1148/2256 (50.9%) | <0.001 |
| Age (years), mean ± SD | 7.5 ± 0.9 | 7.7 ± 1.1 | <0.001 |
| BMI (kg/m2), mean ± SD | 16.95 ± 2.4 | 16.87 ± 2.6 | 0.677 |
| Parental allergic diseases, yes | 97/227 (42.7%) | 582/2114 (27.5%) | <0.001 |
| Maternal educational levels, ≤ High school | 133/222 (59.9%) | 1261/1967 (64.1%) | 0.218 |
| Parental monthly income, < 3000 USD | 152/230 (66.1%) | 1501/2132 (70.4%) | 0.175 |
| ETS exposure, yes | 106/227 (46.7%) | 910/2004 (45.4%) | 0.712 |
| Atopy on skin prick tests | 104/234 (44.4%) | 583/2254 (25.9%) | <0.001 |
| Total serum IgE (IU/ml), mean [range] | 454 [3.80–4630] | 250.80 [1.40–6934] | <0.001 |
| Blood eosinophils (%), mean [range] | 4.67 [0.50–39.10] | 3.57 [0–22.60] | <0.001 |
| AR diagnosis, ever | 107/234 (45.7%) | 462/2081 (22.2%) | <0.001 |
| AD diagnosis, ever | 99/233 (42.5%) | 642/2075 (30.9%) | <0.001 |
| FEV1 % predicted | 102.4 ± 13.77 | 106.1 ± 12.96 | <0.001 |
| FEV1/FVC | 88.86 ± 6.06 | 90.86 ± 5.54 | <0.001 |
| FEF25–75% % predicted | 91.92 ± 21.88 | 99.91 ± 22.64 | <0.001 |
| BHR (PC20 < 8 mg/ml) | 80/221 (36.2%) | 408/2204 (18.5%) | <0.001 |
Data are presented as number (%) or mean ± standard deviation
Definition of abbreviations: AD atopic dermatitis, AR allergic rhinitis, BHR methacholine PC20 < 8mg/ml, BMI, body mass index, ETS environmental tobacco smoke, FEF 25–75% Forced expiratory flow at 25–75% of forced vital capacity, FEV 1 Forced expiratory volume in 1 s, FVC Forced vital capacity, LCA latent class analsis, SD standard deviation, USD US dollars