Table 1. Socio-demographic and health characteristics of the survey respondents.

Characteristics		Number of respondents	% of respondents
Sex	Men	291	41.4
	Women	412	58.6
Age (years)	(Mean ± SD)	45.6±15.2	-
	20–29	126	17.9
	30–39	138	19.6
	40–49	147	20.9
	50–59	157	22.3
	≥60	135	19.2
Education level	Postgraduate	65	9.3
	College	416	59.2
	High school	178	25.3
	Middle school	28	4.0
	Primary school or below	16	2.3
Monthly family incomea (million KRW)	<1.00	42	6.0
	1.00–2.99	209	29.7
	3.00–4.99	242	34.4
	5.00–6.99	130	18.5
	≥ 7.00	74	10.5
	Unanswered	6	0.9
Self-assessed health status	Very good	59	8.4
	Good	325	46.2
	Fair	227	32.3
	Poor	82	11.7
	Very poor	10	1.4
Medication history in the past 3 months	None	245	34.9
	<1 month	244	34.7
	≥1 month	214	30.4
Experience of medicine switch due to lack of efficacy	Yes	367	52.2
	No	336	47.8
Experience of drug adverse events	Yes	245	34.9
	No	458	65.2
To the contribution of NHI in public health improvement	Strongly agree	190	27.0
	Agree	326	46.4
	Neutral	153	21.8
	Disagree	26	3.7
	Strongly disagree	8	1.1

N = 703 respondents

SD = standard deviation; KRW = Korean currency, won; NHI = National Health Insurance.

^aOne US dollar equals approximately 1,100 Korean won in 2010s. The mean monthly family income in 2010 was 3.58 million KRW according to the 2010 Korea National Health and Nutrition Examination Survey.