Table 1. Weighted characteristics of the study subjects (aged ≥ 40 years) in the KNHANES 2010–2016.

Characteristics		No chronic cough	Chronic cough	P value
Prevalence (%)		96.52 ± 0.17	3.48 ± 0.17	-
Age (yr)		55.89 ± 0.12	57.27 ± 0.55	0.012
Cough duration (yr)		-	7.76 ± 0.46	-
Men (%)		47.64 ± 0.36	60.80 ± 2.22	< 0.001
Smoking history (%)				< 0.001
	Never	56.26 ± 0.40	39.43 ± 2.26
	Former	23.66 ± 0.35	17.56 ± 1.67
	Current	20.08 ± 0.37	43.01 ± 2.40
BMI category (%)				0.350
	< 18.5 kg/m2	1.62 ± 0.11	1.97 ± 0.51
	18.5–24.9 kg/m2	60.71 ± 0.42	57.10 ± 2.09
	25.0–29.9 kg/m2	33.29 ± 0.41	36.40 ± 2.02
	≥ 30 kg/m2	4.38 ± 0.18	4.52 ± 0.94
Educational level (%)				0.005
	Elementary school	26.46 ± 0.50	32.78 ± 1.99
	Middle school	14.5 ± 0.32	16.13 ± 1.62
	High school	33.93 ± 0.47	29.97 ± 2.17
	University	25.11 ± 0.58	21.11 ± 1.90
Low household income (%)		50.08 ± 0.62	53.45 ± 2.30	0.152
Blue collar occupation (%)		31.48 ± 0.59	33.22 ± 2.29	0.448
Medical conditions (%)
	Asthma	1.41 ± 0.10	11.74 ± 1.39	< 0.001
	COPD*	0.19 ± 0.04	3.04 ± 0.71	< 0.001
	Allergic rhinitis†	8.49 ± 0.30	13.16 ± 1.76	0.009
	Diabetes mellitus	9.37 ± 0.24	11.94 ± 1.37	0.109
	Hypertension	25.66 ± 0.41	26.27 ± 1.96	0.769
	Dyslipidemia	12.22 ± 0.28	11.81 ± 1.58	0.771
	Angina/MI	2.26 ± 0.12	3.25 ± 0.78	0.132
	Stroke	3.48 ± 1.78	2.92 ± 0.97	0.590
	Arthritis	13.45 ± 0.31	18.6 ± 1.72	< 0.001
	Depression	2.46 ± 0.14	4.85 ± 0.91	0.003

Categorical variables are summarized as weighted percentages ± SEs and continuous variables as weighted means ± SEs.

KNHANES, Korean National Health and Nutrition Examination Survey; BMI, body mass index; COPD, chronic obstructive pulmonary disease; MI, myocardial infarction; SE, standard error.

^*A COPD patient was defined as one who required current treatment; other medical conditions in this table indicate a diagnostic history and current disease; ^†Allergic rhinitis was assessed only in the KNHANES 2013–2015 study.