Table 1 Exclusion and censoring criteria
Medical condition | International classification of disease, 9th modification ICD-9 diagnosis code |
|---|---|
Emphysema | 492.x |
Chronic obstructive pulmonary disease including chronic bronchitis | 490.x–491.x |
Bronchiectasis | 494.x |
Chronic airway obstruction | 496.x |
Chronic respiratory conditions due to fumes and vapors | 506.4 |
Cystic fibrosis | 277.0 |
Prior history of asthma | 493.x |