Table 4.

Health care resource utilization stratified by a concomitant diagnosis of asthma, early versus late diagnosis

Variablea	Early diagnosis			Late diagnosis
	Concomitant asthma (N=648)	COPD only (N=3,222)	p-valueb	Concomitant asthma (N=3,868)	COPD only (N=4,959)	p-valueb
Mean age, years	66.27	69.21	<0.0001	68.51	70.22	<0.001
Number of hospital visits per year for any reason	0.35	0.42	0.0912	0.60	0.53	0.0225
Number of out hospital visits per yearc	1.11	1.41	0.0168	2.20	2.27	0.4461
Number of primary care contacts per year	7.44	7.82	0.4790	15.97	11.16	<0.0001
Patients with overnight stays,%	28.70	33.80	0.0118	41.11	38.66	0.0196
Patients with primary care contact,%	79.48	78.21	0.4758	82.01	74.61	<0.0001

Notes: ^aAll variables except age itself are calculated with age as a covariate. Data are for the 2 years prior to COPD diagnosis. ^bp-values indicate comparisons between patients with a concomitant diagnosis of asthma and those with COPD-only. ^cOut hospital visit: a visit where the patient does not stay overnight at the hospital.