Table 1. Characteristics of Korean adults (55–74 years) according to self-reported smoking status (n = 5,480).

Characteristics	Non-NLST (unweighted n = 4,559)	NLST-former (unweighted n = 489)	NLST-current (unweighted n = 432)	P value
Sex, male	36.1 (0.7)	98.0 (0.9)	97.3 (1.1)	< .001*
Age (mean, years)	63.2 (0.1)	63.7 (0.3)	61.6 (0.3)	< .001†
BMI (mean, years)	24.3 (0.1)	24.3 (0.2)	23.3 (0.2)	< .001†
Obesity (BMI ≥25 kg/m2)	38.7 (1.0)	39.8 (2.7)	25.7 (2.3)	.001*
Spouse, yes	80.7 (0.7)	90.8 (1.8)	90.8 (1.7)	< .001*
Household income				.846*
Lowest quartile	28.9 (1.0)	28.2 (2.4)	31.4 (2.6)
2nd and 3rd quartile	51.2 (1.1)	50.3 (2.7)	49.4 (2.7)
Highest quartile	19.9 (0.9)	21.4 (2.4)	19.2 (2.4)
Education				< .001*
Less than elementary school	52.6 (1.1)	42.3 (2.9)	39.0 (3.0)
Middle or high school	37.9 (1.0)	47.0 (2.8)	54.1 (3.0)
College and above	9.5 (0.7)	10.7 (1.6)	6.9 (1.5)
Insurance				.005*
National health insurance	97.5 (0.3)	94.6 (1.3)	96.5 (1.0)
Medical aid	2.5 (0.3)	5.4 (1.3)	3.5 (1.0)
Private Insurance, yes	59.3 (1.0)	56.9 (2.8)	55.0 (3.2)	.316*
Heavy alcohol drinker	15.2 (0.8)	36.3 (2.9)	49.3 (2.8)	< .001*
Routine exercise	46.8 (1.0)	49.9 (2.8)	44.4 (3.2)	.390*
HTN	41.0 (1.0)	45.0 (2.7)	29.5 (2.6)	< .001*
DM	14.0 (0.6)	19.0 (2.2)	23.1 (2.5)	< .001*
Hyperlipidemia	19.1 (0.8)	16.9 (2.2)	15.3 (2.3)	.217*
Perceived health status				.266*
Good to very good	28.6 (0.9)	28.6 (2.5)	24.4 (2.5)
Normal	45.2 (1.0)	49.1 (2.8)	49.2 (2.8)
Poor to very poor	26.2 (0.8)	22.3 (2.4)	26.4 (2.6)

Values are weighted means (standard errors of means) or weighted percentages (standard errors of percentages).

*Pearson’s chi-squared test.

^†Student’s t-test

Abbreviations: BMI, body mass index; HTN, hypertension; DM, diabetes mellitus