Prevalence of asthmatic symptoms and atopic sensitization in Chinese schoolchildren by study area
| Hong Kong | Beijing | Guangzhou | |
| Written questionnaire n | 3110 | 4227 | 3565 |
| Symptoms in last 12 months | |||
| Wheeze | 5.8 (5.0–6.7) | 3.8 (3.3–4.4) | 3.4 (2.8–4.1) |
| Exercise-induced wheeze | 7.7 (6.8–8.6) | 4.5 (3.9–5.2) | 3.1 (2.5–3.7) |
| Speech-limiting wheezing | 1.8 (1.3–2.3) | 0.5 (0.3–0.7) | 0.4 (0.3–0.7) |
| Current asthma | 3.3 (2.7–4.1) | 2.3 (1.9–2.8) | 2.1 (1.7–2.6) |
| Skin-prick test n | 1341 | 1044 | 1094 |
| Atopy (≥1 positive skin test) | 41.2 (38.6–43.8) | 23.9 (21.4–26.6) | 30.8 (28.1–33.7) |
| Dermatophagoides pteronyssinus | 34.1 (31.5–36.7) | 7.5 (5.9–9.3) | 20.0 (17.7–22.5) |
| Dermatophagoides farinae | 25.9 (23.6–28.3) | 5.7 (4.3–7.2) | 17.9 (15.7–20.3) |
| Cat | 3.7 (2.8–4.9) | 5.6 (4.3–7.1) | 4.3 (3.2–5.7) |
| Cockroach | 11.5 (9.8–13.3) | 13.3 (11.3–15.6) | 17.3 (15.1–19.7) |
| Mixed grass pollen | 0.7 (0.4–1.4) | 1.2 (0.7–2.1) | 1.1 (0.6–1.9) |
| Alternaria tenuis | 0.4 (0.1–0.9) | 1.5 (0.9–2.5) | 0.9 (0.4–1.7) |
| Mixed moulds | 0.4 (0.2–1.0) | 3.2 (2.2–4.4) | 1.2 (0.6–2.0) |
| Mixed tree pollen | 0.1 (0.0–0.4) | 1.0 (0.5–1.8) | 0.5 (0.2–1.2) |
| Subjects n | |||
| Bronchial challenge test | 238 | 193 | 177 |
| Current wheeze | 112 | 91 | 82 |
| No current wheeze | 126 | 102 | 95 |
Data are presented as n % (95% CI) unless otherwise
CI: confidence interval