Table 1. Demographic Characteristics and Comorbid Medical Disorders for Subjects with COPD and in the Comparison Cohort in LHID main Database and NHIS validation Database, 2004–2006.

	Main study				Validation study
Variable	Subjects with COPD		Comparison Subjects		Subjects with COPD		Comparison Subjects
	N = 10,413		N = 41,652		N = 471		N = 1896
	No.	%	No.	%	No.	%	No.	%
Gender
Male	6848	65.8	27392	65.8	288	61.1	1164	61.4
Female	3565	34.2	14260	34.2	183	38.9	732	38.9
Age (years-old)
51–60	1868	17.9	7472	17.9	116	24.6	464	24.5
61–70	2853	27.4	11412	27.4	141	29.9	564	29.7
> 70	5692	54.7	22768	54.7	214	45.4	868	45.8
Hypertension
Yes	6500	62.4	22789	54.7	208	44.2	782	41.2
No	3913	37.6	18863	45.3	263	55.8	1114	58.8
Hyperlipidemia
Yes	2689	25.8	10121	24.3	89	18.9	301	15.9
No	7724	74.2	31531	75.7	382	81.1	1595	84.1
Coronary heart disease
Yes	3840	36.9	10374	24.9	99	21.0	251	13.2
No	6573	63.1	31278	75.1	372	79.0	1645	86.8
Diabetes
Yes	2668	25.6	9990	24.0	83	17.6	298	15.7
No	7745	74.4	31662	76.0	388	82.4	1598	84.3
Smoking
Yes					163	34.6	584	30.8
No					308	65.4	1312	69.2
Drinking
Yes					132	28.0	526	27.7
No					339	72.0	1370	72.3
BMI (SD)					23.9 (3.8)		24.1 (3.6)

Abbreviation: COPD = chronic obstructive pulmonary disease