Table 1

Characteristics of Included and Excluded Participants Measured Before Prednisolone Test Treatment

Characteristics	Included N=233	Excluded N=167	P Value
History
Age, mean (SD), y	63 (9)	63 (9)	.7^a
Male, %	49	40	.1^b
Duration of cough, mean [median] (SD)^d	110 [42] (197)	89 [35] (171)	.30^c
Current smoker, %	27	24	.4^b
Pack years of smoking mean [median] (SD)	19 [10] (24)	12 [4] (20)	.01^c
Allergy for pollen or dust mite, %	14	13	.8^b
Current use inhaled steroids, %	13	10	.3^b
Spirometry^d
FEV₁, mean (SD), L	2.6 (0.8)	2.7 (0.7)^e	.7^a
FEV₁, predicted mean (SD), %	93 (20)	96 (19)^e	.3^a
FVC, predicted mean (SD), %	103 (19)	102 (19)^e	.4^a
FEV₁/FVC, mean (SD), %	73 (10)	76 (12)^e	.004^a