A longitudinal study of adult-onset asthma incidence among HMO members

Table 1 Exclusion criteria used to identify at-risk population*

	Description	ICD-9 (CPT) Codes ^†
1	Heart Failure	428–428.9
2	Bronchitis, chronic bronchitis, and emphysema	490–492.8
3	Pulmonary hypertension, embolism and other pulmonary heart disease	415–416.9
4	Chronic obstructive pulmonary disease	496
5	ER visit or hospital admission for primary asthma diagnosis	493–493.91
6	Occupational asthma diagnosis	504–507, 495.8, 507.8
7	Asthma diagnosis AND outpatient nebulization treatment	493–493.91 AND (94640)
8	Ordered second line asthma medications^‡
9	Any asthma diagnosis AND ordered oral steroids	493–493.91
10	Asthma diagnosis AND ordered 4 or more MDIs^¶	493–493.91

* Exclusion criteria were applied to records for the 12 months preceding the index month. ^†International Classification of Diseases 9^th Edition and Current Procedural Terminology codes; ^‡ Second line medications included cromolyn, necrodomyl, aerosolized steroids, theophylline, oral or nebulized Beta-agonists, and leukotriene inhibitors; ^¶MDI= Beta-agonist metered dose inhaler.

ISSN: 1476-069X