TABLE 3.

International Classification of Diseases ninth revision (ICD-9) code 490 (bronchitis, not specified as acute or chronic) analysis

Prevalence	COPD prevalence: ICD-9 491, 492, 496; %		COPD prevalence: ICD-9 491, 492, 496; 490; %
	Male	Female	Male	Female
All ages	4.70	4.00	9.50	10.50
Age 65 years and older	10.80	7.90	16.30	15.10
Age 45–64 years	1.90	1.60	6.30	7.80
	Subgroup: ICD-9 491, 492, 496 only; %		Subgroup: ICD-9 490 only; %
COPD medication use	45		11
Lung function testing	55		23

ICD-9 codes 491: chronic bronchitis; 492: emphysema; and 496: unspecified chronic obstructive pulmonary disease (COPD)