Table 4.
Risk Factor Association with the Wheeze Clusters at 18-years
| Cluster 1 (n=38) % (count) |
Cluster 2 (n=75) % (count) |
Cluster 3 (n=30) % (count) |
Cluster 4 (n=60) % (count) |
Cluster 5 (n=76) % (count) |
Cluster 6 (n=30) % (count) |
p-value | |
|---|---|---|---|---|---|---|---|
| Male Gender | 63.2 (24) | 53.3 (40) | 26.7 (8) | 30.0 (18) | 32.9 (25) | 73.3 (22) | <0.0001 |
| Family history of asthma |
57.9 (22) | 66.7 (50) | 80.0 (24) | 51.7 (31) | 64.5 (49) | 60.0 (18) | 0.15 |
| Low birth weight | 2.7 (1) | 10.7 (8) | 0 | 3.4 (2) | 1.4 (1) | 3.5 (1) | 0.06 |
| Exclusively breastfed | 31.0 (9) | 19.7 (12) | 25.0 (7) | 32.6 (15) | 30.7 (19) | 32.0 (8) | 0.66 |
| Chest infection in Infancy |
14.8 (4) | 29.8 (17) | 18.5 (5) | 16.3 (7) | 19.4 (13) | 20.8 (5) | 0.54 |
| Personal smoking | 51.4 (19) | 55.1 (38) | 69.0 (20) | 74.6 (44) | 49.3 (37) | 51.7 (15) | 0.04 |
| Maternal smoking in pregnancy |
36.8 (14) | 42.7 (32) | 33.3 (10) | 33.3 (20) | 38.2 (29) | 26.7 (8) | 0.71 |
| Mean Cord IgE | −0.62 | −0.77 | −0.69 | −0.82 | −0.76 | −0.78 | 0.55 |
| Mean Paracetamol Use |
2.32 | 1.92 | 2.11 | 2.79 | 2.45 | 2.81 | 0.61 |
| Mean BMI | 24.80 | 24.86 | 24.88 | 23.26 | 23.49 | 23.13 | 0.62 |
Family History of asthma = Family (parent or sibling) history of asthma.
Low Birth weight = Low Birth Weight (<2.5kg).
Exclusively Breastfed = Exclusively breastfed for > 3 months.
Chest infection in infancy = History of recurrent chest infections at 1 or 2-years.
Personal Smoking = Personal (past or current) history of cigarette smoking.
Maternal Smoking = Maternal smoking history during pregnancy.
Cord IgE = Cord blood IgE at birth.
Paracetamol Use = Paracetamol use at 18-years.
BMI = Body Mass Index (Weight [Kg]/ Height2 [M]) at 18-years.
the p-values are for the tests comparing the distribution patterns of a categorical variable in each cluster or comparing medians (continuous variables) across the 6 clusters. For categorical variables, chi-square tests were implemented and for continuous variables Kruskal-Wallis tests were used due to the violation of the normality assumption in the residuals.