Table 2. Demographic characteristics of traits across clusters.
| Characteristics | Cluster 1 | Cluster 2 | Cluster 3 | Cluster 4 | P value | Bonferroni | ||
|---|---|---|---|---|---|---|---|---|
| Age | 8.8 ± 2.1 | 8.9 ± 2.2 | 13.2 ± 1.8 | 7.5 ± 2.0 | < 0.0001 | 3 vs. 2, 1, 4 | ||
| Male | 156 (72.2) | 56 (70.9) | 10 (21.3) | 64 (61.0) | < 0.0001 | 1, 2 vs. 4 | ||
| Asthma history | < 0.0001 | 1, 2, 4 vs. 3 | ||||||
| Age of asthma onset (yr) | ||||||||
| < 3 | 35 (16.2) | 18 (22.8) | 0 (0) | 22 (21.0) | ||||
| ≥ 3, < 6 | 69 (31.9) | 33 (41.8) | 6 (12.8) | 44 (41.9) | ||||
| ≥ 6, < 9 | 76 (35.2) | 22 (27.9) | 6 (12.8) | 23 (21.9) | ||||
| ≥ 9, < 12 | 33 (15.3) | 5 (6.3) | 14 (29.8) | 14 (13.3) | ||||
| ≥ 12 | 3 (1.4) | 1 (1.3) | 21 (44.7) | 2 (1.9) | ||||
| History of acute bronchiolitis | 83 (38.4) | 29 (36.7) | 4 (8.5) | 31 (29.5) | 0.001 | 1, 2, 4 vs. 3 | ||
| Atopic features | ||||||||
| Current AR diagnosis | 215 (99.5) | 68 (86.1) | 37 (78.7) | 38 (36.2) | < 0.0001 | 1, 2 vs. 3 | ||
| Current AD diagnosis | 5 (2.3) | 78 (98.7) | 11 (23.4) | 0 (0.0) | < 0.0001 | 2, 3 vs. 4 | ||
| Lifetime history of AD diagnosis | 57 (26.4) | 78 (98.7) | 21 (44.7) | 15 (14.3) | < 0.0001 | 1 vs. 2, 3, 4 | ||
| Positive skin test response, atopy (%) | 209 (96.8) | 66 (83.5) | 42 (89.4) | 33 (31.4) | < 0.0001 | 2, 3 vs. 4 | ||
| Total serum IgE levels, kU/L | 347.2 (115.6–1,043.2) | 415.7 (129.0–1,339.4) | 347.2 (64.7–1,863.1) | 149.9 (38.9–578.3) | < 0.0001 | 1 vs. 2, 3 | ||
| Anthropomorphic features | ||||||||
| Tanner stage | < 0.0001 | 2, 4 vs. 3 | ||||||
| I | 178 (82.4) | 68 (86.1) | 2 (4.3) | 95 (90.5) | ||||
| II | 30 (13.9) | 9 (11.4) | 11 (23.4) | 9 (8.6) | ||||
| III | 6 (2.8) | 2 (2.5) | 11 (23.4) | 1 (1.0) | ||||
| IV | 2 (0.9) | 0 (0.0) | 16 (34.04) | 0 (0.0) | ||||
| V | 0 (0.0) | 0 (0.0) | 7 (14.89) | 0 (0.0) | ||||
| BMI (kg/m2) | 18.7 ± 3.6 | 18.3 ± 3.6 | 20.7 ± 3.9 | 17.8 ± 3.0 | < 0.0001 | 3 vs. 1, 2, 4 | ||
All P values for the multiple comparisons were < 0.008 (the adjusted P value based on the Bonferroni correction). Data are presented as number (%) or mean ± standard deviation, unless otherwise indicated.
AR, allergic rhinitis; AD, atopic dermatitis; IgE, immunoglobulin E; BMI, body mass index.