From: Early life swimming pool exposure and asthma onset in children – a case-control study
Age at asthma symptom onset | Number | Percent | |
---|---|---|---|
Pre-school onset | < 1 years of age | 15 | 4.5% |
1 year | 60 | 17.8% | |
2 years | 21 | 6.2% | |
3 years | 17 | 5.0% | |
4 years | 16 | 4.7% | |
5 years | 13 | 3.9% | |
6 years | 26 | 7.7% | |
School-age onset | 7–15 years | 169 | 50.1% |
All cases | 337 | 100.0% |