Supplementary Table 4:
ICD-9 Codes Used to Define Chronic Obstructive Pulmonary Disease Cohort
| ICD-9-CM Diagnosis Codes | Description |
|---|---|
| 491.21 | Obstructive chronic bronchitis with (acute) exacerbation |
| 491.22 | Obstructive chronic bronchitis with acute bronchitis |
| 491.8 | Other chronic bronchitis |
| 491.9 | Unspecified chronic bronchitis |
| 492.8 | Other emphysema |
| 493.20 | Chronic obstructive asthma, unspecified |
| 493.21 | Chronic obstructive asthma with status asthmaticus |
| 493.22 | Chronic obstructive asthma with (acute) exacerbation |
| 496 | Chronic airway obstruction, not elsewhere classified |
| Principal discharge diagnosis codes included in cohort if combined with a secondary diagnosis of COPD with exacerbation (491.21, 491.22, 493.21, or 493.22) | |
| 518.81 | Acute respiratory failure |
| 518.82 | Other pulmonary insufficiency, not elsewhere classified |
| 518.84 | Acute and chronic respiratory failure |
| 799.1 | Respiratory arrest |