Table 4. Linear regression analyses for CHQ score in 478 patients with chronic cough.

For CHQ score		Univariate analyses		Multivariate analyses*
		Coefficient (95% CI)	P value	Coefficient (95% CI)	P value
Age		−0.06 (−0.08 to −0.03)	< 0.001	−0.06 (−0.08 to −0.04)	< 0.001
Male sex		−1.16 (−1.94 to −0.38)	0.004	−1.08 (−2.02 to −0.15)	0.022
Smoking status
	Never smoker	Reference		Reference
	Ex-smoker	−1.06 (−2.03 to −0.09)	0.033	−0.10 (−1.18 to 0.97)	0.850
	Current smoker	−0.79 (−2.18 to 0.59)	0.259	−0.34 (−1.83 to 1.14)	0.650
Cough duration
	2 to 6 months	Reference		Reference
	6 to 12 months	−0.45 (−1.57 to 0.66)	0.425	−0.40 (−1.48 to 0.68)	0.465
	1 to 5 years	0.67 (−0.29 to 1.63)	0.171	0.09 (−0.90 to 1.07)	0.865
	> 5 years	−0.56 (−1.53 to 0.41)	0.259	−1.02 (−2.03 to −0.01)	0.049
Unexplained chronic cough		2.28 (1.21 to 3.34)	< 0.001	2.64 (1.49 to 3.78)	< 0.001

CHQ, cough hypersensitivity questionnaire; CI, confidence interval.

^*Adjusted for age, sex, smoking status, cough duration, and unexplained chronic cough group.