Table 4. Prevalence of putative COPD by diagnostic category of asthma.

Diagnosis criteria for asthmaa	Possible asthma [n (%)]	Putative COPD [n (%)]	Prevalence of putative COPD in study population (%)
			Crude	Age- and sex-standardized
None of four criteria affirmative	54 (62.8)	32 (37.2)	4.3	4.0
Any one of four criteria affirmative	36 (41.9)	50 (58.1)	6.7	6.2
Any two of four criteria affirmative	16 (18.6)	70 (81.4)	9.4	8.7
Any three of four criteria affirmative	4 (4.7)	82 (95.3)	11.0	10.4
Four of four criteria affirmative	0 (0.0)	86 (100.0)	11.5	10.9
Physician-diagnosed asthma	8 (9.3)	78 (90.7)	10.5	10.0

^a Criteria for asthma diagnosis: self-reported history of asthma; history of wheezing in the past 12 months; frequent or occasional wheezes; physician-diagnosed asthma