Table 4. Multivariate analysis of the determinants of capsaicin cough hypersensitivity.

Variables	C5≤62.5 µmol (No., %)	C5>62.5 µmol (No., %)	Multivariable regression model
			OR	95%CI	P
Sex
Male	11 (21.2)	41 (49.4%)	-	Reference	-
Female	41 (78.8%)	42 (50.6%)	3.25	1.35-7.83	<0.01
HRCT total score
≤6	16 (30.8%)	50 (60.2%)	-	Reference	-
7-12	28 (53.8%)	26 (31.3%)	2.57	1.07-6.17	0.04
≥13	8 (15.4%)	7 (8.4%)	2.32	0.66-8.17	0.19
BSI
0-4	11 (21.2%)	41 (49.4%)	-	Reference	-
5-8	24 (46.2%)	25 (30.1%)	4.05	1.48-11.06	<0.01
≥9	17 (32.7%)	17 (20.5%)	4.38	1.48-12.93	<0.01

Categorical data were expressed as number (percentage) and compared with chi-square test.

Data in boldface indicated statistical significance.

In multivariate analysis, settings of the covariates were as follows: Sex: 0 for female, 1 for males; duration of cough: 0 for less than 5 years, 1 for 5 to 10 years, 2 for greater than 10 years; HRCT score: 0 for 6 or less, 1 for greater than 7 and less than 13, 2 for 13 or greater; bronchiectasis severity index: 0 for 4 or less, 1 for 5 to 8, 2 for 9 or greater; 24-hour sputum volume: 0 for 10 ml or less, 1 for greater than 10 and less than 30 ml, 2 for 30 ml or greater; cough symptom score: 0 for 5 or less, 1 for greater than 5; sputum bacteriology: 0 for commensals, 1 for Pseudomonas aeruginosa, 2 for other PPMs.