Table 2.
Results of latent class analysis
| Cluster | Cluster 1 | Cluster 2 | Cluster 3 | Cluster 4 |
|---|---|---|---|---|
| Number, n (%) | 51 (21.7%) | 40 (17.0%) | 29 (12.3%) | 115 (49.1%) |
| Sex, Male | 28/51 (54.9%) | 30/40 (75.0%) | 14/29 (48.3%) | 77/115 (67.0%) |
| Body mass index | ||||
| Normal | 43/51 (84.3%) | 31/39 (79.5%) | 29/29 (100.0%) | 88/111 (79.3%) |
| Overweight | 8/51 (15.7%) | 1/39 (2.6%) | 0/29 (0.0%) | 16/111 (14.4%) |
| Obesity | 0/51 (0.0%) | 7/39 (17.9%) | 0/29 (0.0%) | 7/111 (6.3%) |
| Family history of allergic diseases, yes | 28/50 (56.0%) | 14/38 (36.8%) | 16/26 (61.5%) | 39/113 (34.5%) |
| Monthly income, < 3000 USD | 32/49 (65.3%) | 21/40 (52.5%) | 26/28 (92.9%) | 73/113 (64.6%) |
| Maternal educational level | ||||
| Less than high school | 30/46 (65.2%) | 15/36 (41.7%) | 21/29 (72.4%) | 67/111 (60.4%) |
| Exposure to ETS, yes | 12/50 (24.0%) | 20/38 (52.6%) | 17/28 (60.7%) | 57/111 (51.4%) |
| Atopy, yes | 46/51 (90.2%) | 18/40 (45.0%) | 27/29 (93.1%) | 13/114 (11.4%) |
| Onset age of first wheezing | ||||
| < 1 year | 10/44 (22.7%) | 5/35 (14.3%) | 0/28 (0.0%) | 18/103 (17.5%) |
| 1–3 years | 9/44 (20.5%) | 9/35 (25.7%) | 6/28 (21.4%) | 46/103 (44.7%) |
| 3–6 years | 11/44 (25.0%) | 14/35 (40.0%) | 17/28 (60.7%) | 29/103 (28.2%) |
| ≥ 6 years | 14/44 (31.8%) | 7/35 (20.0%) | 5/28 (17.9%) | 10/103 (9.7%) |
| Number of absence days from school due to wheezinga | ||||
| 0 | 51/51 (100.0%) | 24/40 (60.0%) | 18/29 (62.1%) | 115/115 (100.0%) |
| 1–3 days | 0/51 (0.0%) | 15/40 (37.5%) | 5/29 (17.2%) | 0/115 (0.0%) |
| 4–6 days | 0/51 (0.0%) | 0/40 (0.0%) | 4/29 (13.8%) | 0/115 (0.0%) |
| ≥ 7 days | 0/51 (0.0%) | 1/40 (2.5%) | 2/29 (6.9%) | 0/115 (0.0%) |
| Number of nocturnal awakening days due to wheezinga | ||||
| 0 | 51/51 (100.0%) | 13/40 (32.5%) | 9/29 (31.0%) | 115/115 (100.0%) |
| < 1 /week | 0/51 (0.0%) | 24/40 (60.0%) | 15/29 (51.7%) | 0/115 (0.0%) |
| ≥ 1 /week | 0/51 (0.0%) | 3/40 (7.5%) | 5/29 (17.2%) | 0/115 (0.0%) |
| Number of asthma attacka | ||||
| 0 | 42/51 (82.4%) | 0/40 (0.0%) | 0/29 (0.0%) | 108/115 (93.9%) |
| 1–3 | 9/51 (17.6%) | 26/40 (65.0%) | 11/29 (37.9%) | 7/115 (6.1%) |
| 4–12 | 0/51 (0.0%) | 8/40 (20.0%) | 7/29 (24.1%) | 0/115 (0.0%) |
| ≥ 13 | 0/51 (0.0%) | 6/40 (15.0%) | 11/29 (37.9%) | 0/115 (0.0%) |
| Asthma treatmenta, yes | 19/51 (37.3%) | 32/40 (80.0%) | 27/29 (93.1%) | 21/115 (18.3%) |
| Total serum IgE ≥100 IU/mL | 50/51 (98.0%) | 24/40 (60.0%) | 28/28 (100.0%) | 30/111 (27.0%) |
| Blood eosinophil ≥4% | 28/51 (54.9%) | 24/40 (60.0%) | 23/29 (79.3%) | 29/112 (25.9%) |
| BHR <8 mg/ml | 22/49 (44.9%) | 12/38 (31.6%) | 21/26 (80.8%) | 25/108 (23.1%) |
| FEV1 < 80% predicted | 7/47 (14.9%) | 0/39 (0.0%) | 4/29 (13.8%) | 1/113 (0.9%) |
| FEV1/FVC <80% predicted | 1/49 (2.0%) | 0/40 (0.0%) | 11/29 (37.9%) | 8/114 (7.0%) |
| FEF25–75% <65% predicted | 5/29 (17.2%) | 0/30 (0.0%) | 8/19 (42.1%) | 4/90 (4.4%) |
ain the previous 12 months
Definition of abbreviations: BHR methacholine PC20 < 8mg/ml, 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, USD US dollars