Prevalence, Trend, and Risk Factors for Early Chronic Obstructive Pulmonary Disease: An Analysis of the Nationwide Population-Based Survey from 2010 to 2019 in South Korea

Figures & data

Table 1. Characteristics of study participants aged 40–49 years by survey year.

	Total (n = 8766)	2010 (n = 879)	2011 (n = 892)	2012 (n = 865)	2013 (n = 837)	2014 (n = 876)	2015 (n = 758)	2016 (n = 760)	2017 (n = 938)	2018 (n = 974)	2019 (n = 947)
Population size	82,326,178	8,176,938	8,225,753	8,140,883	8,057,616	8,165,449	8,255,888	8,501,859	8,356,390	8,373,778	8,071,618
Male	50.6 (0.5)	51.1 (1.9)	50.6 (1.7)	50.1 (1.7)	49.5 (1.7)	50.5 (1.7)	50.6 (1.8)	50.6 (1.7)	50.9 (1.8)	51.1 (1.7)	51.1 (1.4)
Age	44.7 (0.1)	44.5 (0.1)	44.6 (0.2)	44.5 (0.1)	44.5 (0.1)	44.6 (0.1)	44.6 (0.1)	44.6 (0.1)	44.6 (0.1)	44.7 (0.1)	44.7 (0.1)
Residence
Urban	85.3 (1.0)	76.2 (4.5)	81.4 (3.9)	84.5 (3.2)	84.8 (3.2)	84.2 (3.2)	86.6 (2.7)	87.7 (2.5)	91.3 (2.1)	88.2 (3.0)	88.2 (2.8)
Rural	14.7 (1.0)	23.8 (4.5)	18.6 (3.9)	15.5 (3.2)	15.2 (3.2)	15.8 (3.2)	13.4 (2.7)	12.3 (2.5)	8.7 (2.1)	11.8 (3.0)	11.8 (2.8)
Education
High school or lower	47.8 (0.8)	60.9 (2.6)	58.7 (2.6)	56.6 (2.8)	52.1 (2.4)	48.1 (2.9)	50.4 (2.8)	43.5 (2.5)	39.1 (2.6)	37.9 (2.4)	31.4 (2.0)
College or more	52.2 (0.8)	39.1 (2.6)	41.3 (2.6)	43.4 (2.8)	47.8 (2.3)	51.9 (2.9)	49.6 (2.8)	56.5 (2.5)	60.9 (2.6)	62.1 (2.4)	68.6 (2.0)
Household income
Lowest	6.9 (0.4)	9.9 (1.5)	7.5 (1.2)	7.5 (1.5)	7.8 (1.3)	4.7 (0.9)	7.4 (1.2)	7.2 (1.1)	5.8 (1.0)	5.8 (0.9)	5.5 (1.0)
Lower middle	24.2 (0.7)	29.7 (2.7)	32.7 (2.2)	26.5 (2.4)	26.5 (2.1)	22.6 (2.3)	20.5 (2.1)	20.1 (1.9)	21.8 (2.1)	21.4 (2.0)	20.8 (2.0)
Higher middle	32.0 (0.7)	29.5 (2.2)	27.6 (1.9)	32.0 (2.4)	26.4 (2.1)	36.4 (2.1)	32.0 (2.3)	33.3 (2.5)	31.4 (2.1)	37.2 (2.0)	33.5 (2.2)
Highest	36.9 (0.8)	30.8 (2.5)	32.3 (2.4)	33.9 (2.6)	39.3 (2.9)	36.2 (2.8)	40.1 (2.6)	39.4 (3.0)	41.0 (2.7)	35.6 (2.5)	40.2 (2.9)
Smoking
Never	54.6 (0.6)	53.0 (1.8)	53.5 (1.9)	54.8 (1.9)	59.3 (2.0)	54.1 (2.0)	56.1 (1.9)	55.5 (1.7)	53.9 (2.0)	53.2 (2.0)	52.4 (1.9)
Former	19.5 (0.5)	15.8 (1.5)	19.6 (1.5)	19.1 (1.7)	16.1 (1.5)	15.6 (1.7)	19.3 (1.5)	20.0 (1.6)	21.5 (1.7)	21.2 (1.7)	26.8 (1.8)
Current	25.9 (0.6)	31.2 (2.0)	29.6 (1.9)	26.1 (1.9)	24.6 (1.7)	30.3 (1.9)	24.7 (1.8)	24.5 (1.7)	24.6 (1.8)	25.6 (1.9)	20.8 (1.6)
Pack-year
<10	73.2 (0.6)	66.8 (1.8)	66.5 (1.9)	68.6 (2.0)	NA	NA	71.3 (1.8)	71.3 (1.7)	73.3 (1.7)	71.0 (1.8)	74.7 (1.6)
≥10	26.8 (0.6)	33.2 (1.8)	33.5 (1.9)	31.4 (2.0)	NA	NA	28.7 (1.8)	28.7 (1.7)	26.7 (1.7)	29.0 (1.8)	25.3 (1.6)
High-risk drinking
<1/week	69.3 (0.6)	67.4 (2.0)	70.3 (1.9)	68.5 (2.3)	70.6 (2.0)	66.6 (2.1)	70.6 (1.9)	69.7 (2.0)	70.3 (1.9)	67.4 (1.9)	71.4 (2.0)
≥1/week	30.7 (0.6)	32.6 (2.0)	29.7 (1.9)	31.5 (2.3)	29.4 (2.0)	33.4 (2.1)	29.4 (1.9)	30.3 (2.0)	29.7 (1.9)	32.6 (1.9)	28.6 (2.0)
Body mass index (kg/m^2)
<23	38.3 (0.6)	37.6 (1.9)	34.1 (1.9)	36.1 (2.2)	43.4 (1.9)	42.2 (2.1)	37.9 (2.0)	36.4 (1.6)	36.9 (1.9)	39.6 (1.8)	39.2 (1.9)
23–24.9	24.7 (0.5)	23.8 (1.8)	27.3 (2.0)	21.7 (1.8)	25.0 (1.6)	25.4 (1.8)	25.9 (1.8)	23.2 (1.6)	26.8 (1.8)	23.4 (1.6)	24.5 (1.6)
≥25	37.0 (0.6)	36.8 (1.9)	38.6 (1.9)	42.2 (1.9)	31.7 (1.7)	32.3 (1.8)	36.2 (2.0)	40.4 (1.9)	36.2 (2.2)	37.0 (1.8)	36.3 (2.0)

Data are presented as percentages with standard error, otherwise stated.

NA, not available.

Figure 1. Prevalence of early COPD in individuals aged 40–49 years according to sex by year. COPD, chronic obstructive pulmonary disease.

Figure 2. Prevalence of early COPD in individuals aged 40–49 years according to sex and smoking status by year. COPD, chronic obstructive pulmonary disease.

Figure 3. Prevalence of early COPD in individuals aged 40–49 years according to sex and smoking pack-years by year. COPD, chronic obstructive pulmonary disease.

Table 2. Estimated percentage prevalence (SE) of early chronic obstructive pulmonary disease in aged 40–49 years according to features.

	Total (n = 8766)	p	2010 (n = 879)	2011 (n = 892)	2012 (n = 865)	2013 (n = 837)	2014 (n = 876)	2015 (n = 758)	2016 (n = 760)	2017 (n = 938)	2018 (n = 974)	2019 (n = 947)
Total	4.5 (0.3)		3.4 (0.7)	5.6 (1.0)	4.5 (0.9)	4.1 (0.7)	6.0 (1.1)	4.6 (0.9)	4.9 (0.8)	3.9 (0.7)	3.7 (0.7)	3.9 (0.7)
Sex		<0.001
Male	6.5 (0.5)		4.8 (1.2)	7.8 (1.6)	7.1 (1.6)	7.1 (1.3)	8.9 (2.0)	7.9 (1.6)	6.8 (1.3)	5.4 (1.2)	5.1 (1.2)	4.5 (1.2)
Female	2.3 (0.2)		2.0 (0.9)	3.4 (1.0)	1.8 (0.7)	1.1 (0.4)	3.1 (0.9)	1.2 (0.6)	2.8 (0.8)	2.3 (0.6)	2.1 (0.7)	3.1 (1.0)
Residence		0.669
Urban	4.4 (0.3)		3.1 (0.8)	5.8 (1.1)	3.3 (0.8)	4.3 (0.8)	6.1 (1.2)	4.7 (0.9)	5.2 (0.9)	3.8 (0.7)	3.6 (0.8)	4.1 (0.8)
Rural	4.7 (0.7)		4.6 (1.6)	4.8 (2.0)	10.8 (30.4)	3.0 (1.4)	5.5 (2.0)	3.8 (2.2)	2.7 (1.0)	4.4 (2.4)	4.3 (1.9)	1.7 (0.9)
Education		0.003
High school or lower	5.2 (0.4)		3.9 (1.0)	5.6 (1.3)	5.0 (1.3)	4.3 (1.0)	6.0 (1.5)	6.0 (1.5)	5.3 (1.2)	3.9 (1.3)	5.4 (1.4)	7.3 (1.6)
College or more	3.7 (0.3)		2.5 (0.9)	4.8 (1.1)	4.2 (1.1)	3.7 (1.0)	5.5 (1.5)	3.5 (1.0)	4.2 (1.0)	4.1 (0.9)	2.8 (0.9)	2.1 (0.7)
Household income		0.206
Lowest	5.9 (1.2)		7.5 (3.5)	9.4 (4.8)	1.0 (1.0)	6.7 (3.4)	17.7 (7.8)	5.7 (4.1)	3.5 (2.5)	1.3 (1.3)	3.9 (2.4)	2.8 (2.1)
Lower middle	4.6 (0.6)		5.1 (1.7)	4.7 (1.6)	4.4 (2.0)	4.3 (1.5)	3.8 (1.8)	4.7 (2.1)	6.4 (1.9)	4.7 (1.7)	3.2 (1.5)	4.8 (1.6)
Higher middle	4.7 (0.5)		2.5 (1.0)	6.2 (1.9)	5.2 (1.7)	4.3 (1.3)	6.0 (1.8)	5.7 (1.8)	5.1 (1.5)	2.7 (1.1)	4.3 (1.2)	4.5 (1.3)
Highest	3.8 (0.4)		1.4 (0.6)	4.3 (1.2)	4.7 (1.4)	3.4 (1.1)	5.3 (1.5)	3.4 (1.2)	4.2 (1.0)	4.7 (1.2)	3.3 (1.4)	3.0 (1.1)
Smoking		<0.001
Never	2.5 (0.3)		2.1 (0.8)	2.9 (0.9)	2.3 (0.8)	1.2 (0.4)	3.5 (1.0)	1.8 (0.8)	2.8 (0.7)	2.8 (0.7)	2.4 (0.7)	3.4 (1.0)
Former	5.0 (0.6)		3.3 (1.9)	7.3 (2.0)	7.3 (3.0)	6.3 (2.3)	4.7 (2.5)	5.8 (2.3)	6.4 (1.9)	3.9 (1.7)	4.0 (1.8)	2.5 (1.2)
Current	7.7 (0.7)		5.6 (1.6)	8.5 (2.4)	7.4 (2.1)	8.8 (2.1)	9.5 (2.7)	9.8 (2.6)	8.3 (2.2)	6.2 (1.8)	6.1 (2.1)	6.9 (2.0)
Pack-year		<0.001
<10	2.6 (0.2)		2.1 (0.7)	3.0 (0.8)	2.4 (0.7)	NA	NA	1.9 (0.7)	2.9 (0.6)	3.0 (0.7)	2.5 (0.6)	2.9 (0.7)
≥10	8.2 (0.7)		6.0 (1.6)	9.8 (2.2)	9.3 (2.3)	NA	NA	11.3 (2.5)	9.6 (2.1)	6.2 (1.8)	6.7 (2.1)	6.6 (2.1)
High-risk drinking		<0.001
<1/week	3.4 (0.3)		2.6 (0.9)	5.2 (1.2)	3.3 (1.0)	2.6 (0.8)	3.8 (1.0)	2.6 (0.9)	3.0 (0.9)	4.2 (0.9)	3.6 (0.9)	3.4 (0.8)
≥1/week	7.1 (0.7)		5.2 (1.7)	6.3 (1.8)	8.0 (2.5)	9.6 (2.2)	8.8 (2.6)	10.6 (2.7)	9.6 (2.1)	4.0 (1.3)	4.0 (1.3)	5.7 (2.2)
Body mass index (kg/m^2)	0.603
<23	4.7 (0.4)		4.6 (1.4)	5.7 (1.5)	5.7 (1.7)	4.9 (1.2)	4.8 (1.3)	3.0 (1.4)	6.6 (1.5)	5.4 (1.3)	3.1 (1.1)	3.3 (1.0)
23–24.9	4.0 (0.5)		4.5 (1.8)	4.5 (1.6)	3.9 (1.4)	3.8 (1.3)	7.2 (2.4)	2.5 (1.3)	3.2 (1.4)	1.3 (0.6)	5.2 (1.8)	4.3 (1.7)
≥25	4.5 (0.4)		1.6 (0.6)	6.4 (1.6)	3.7 (1.3)	3.4 (1.1)	6.7 (1.8)	7.7 (1.9)	4.3 (1.1)	4.2 (1.2)	3.3 (1.1)	4.2 (1.2)

Data are presented as percentages with SE.

COPD, chronic obstructive pulmonary disease; SE, standard error; NA, not available.

Table 3. Estimated odds ratio of factors associated with early chronic obstructive pulmonary disease.

	Univariable		Multivariable + Smoking		Multivariable + Pack-year
	OR (95% CI)	p	OR (95% CI)	p	OR (95% CI)	p
Sex		<0.001		<0.001		0.018
Female	1		1		1
Male	2.99 (2.29–3.89)		1.98 (1.33–2.95)		1.65 (1.09–2.49)
Residence		0.669		0.618		0.74
Urban	1		1		1
Rural	1.07 (0.78–1.47)		0.92 (0.64–1.32)		0.94 (0.65–1.36)
Education		0.003		<0.001		0.002
College or more	1		1		1
High school or lower	1.44 (1.13–1.83)		1.69 (1.28–2.38)		1.58 (1.18–2.12)
Household income		0.051		0.946		0.814
highest	1		1		1
higher middle	1.24 (0.92–1.67)		1.32 (0.82–1.57)		1.24 (0.88–1.73)
lower middle	1.22 (0.89–1.69)		1.06 (0.74–1.52)		1.07 (0.73–1.58)
lowest	1.59 (0.99–2.55)		0.98 (0.57–1.69)		1.02 (0.58–1.81)
Smoking		<0.001		0.002
Never	1		1
Former	2.07 (1.48–2.89)		1.50 (0.97–2.33)
Current	3.24 (2.44–4.30)		1.90 (1.28–2.83)
Pack-year		<0.001				<0.001
<10	1				1
≥10	3.36 (2.58–4.37)				2.63 (1.81–3.84)
High-risk drinking		<0.001		0.013		0.185
<1/week	1		1		1
≥1/week	2.15 (1.65–2.80)		1.40 (1.06–1.86)		1.24 (0.91–1.69)
Body mass index (kg/m^2)		0.797		0.144		0.157
≥25	1		1		1
23–24.9	0.88 (0.64–1.21)		0.94 (0.67–1.32)		1.29 (0.92–1.81)
<23	1.04 (0.79–1.36)		1.28 (0.94–1.76)		0.94 (0.65–1.37)

COPD, chronic obstructive pulmonary disease, CI, confidence interval.

Bold values denote statistical significance at the p < 0.05 level.

Table 4. Estimated percentage prevalence (SE) of early chronic obstructive pulmonary disease among 40–49 years according to sex, smoking status, and smoking amount by year.

	Total	p	2010	2011	2012	2013	2014	2015	2016	2017	2018	2019
Male
Smoking		<0.001
Never	3.8 (0.8)		4.9 (3.4)	1.7 (1.1)	4.9 (3.2)	0.9 (0.9)	5.5 (3.6)	5.7 (3.3)	3.0 (1.7)	4.3 (2.0)	2.7 (1.9)	4.5 (2.4)
Former	5.3 (0.7)		3.6 (2.0)	6.7 (2.0)	7.9 (3.2)	6.8 (2.4)	4.9 (2.9)	6.6 (2.6)	6.2 (2.0)	4.3 (1.9)	4.2 (2.0)	3.0 (1.4)
Current	8.2 (0.8)		5.2 (1.5)	9.1 (2.7)	7.9 (2.3)	9.9 (2.3)	10.2 (3.0)	9.9 (2.8)	9.3 (2.5)	7.0 (2.0)	7.1 (2.4)	6.7 (2.2)
Pack-year		<0.001
<10	3.2 (0.5)		3.6 (1.8)	2.2 (1.0)	3.7 (1.7)	NA	NA	3.3 (1.7)	2.9 (1.2)	4.4 (1.5)	2.9 (1.2)	2.4 (1.1)
≥10	8.3 (0.8)		5.3 (1.5)	9.7 (2.3)	9.5 (2.4)	NA	NA	11.5 (2.6)	10.1 (2.2)	6.4 (1.8)	7.1 (2.2)	6.9 (2.2)
Female
Smoking		0.504
Never	2.2 (0.3)		1.5 (0.8)	3.1 (1.1)	1.9 (0.7)	1.2 (0.5)	3.1 (0.9)	0.9 (0.5)	2.7 (0.8)	2.5 (0.7)	2.3 (0.8)	3.1 (1.1)
Former	2.9 (1.2)		NA	12.6 (8.1)	NA	NA	4.1 (4.1)	NA	7.6 (7.4)	2.2 (2.2)	2.3 (2.3)	NA
Current	3.3 (1.3)		8.9 (7.7)	2.1 (2.1)	2.9 (2.9)	NA	2.8 (2.7)	8.0 (7.6)	1.5 (1.5)	NA	NA	8.1 (4.7)
Pack-year		0.338
<10	2.3 (0.2)		1.5 (0.7)	3.3 (1.0)	1.9 (0.7)	NA	NA	1.2 (0.6)	2.9 (0.8)	2.3 (0.7)	2.2 (0.7)	3.2 (1.0)
≥10	4.6 (3.4)		41.6 (27.9)	10.7 (10.4)	NA	NA	NA	NA	NA	NA	NA	NA

Data are presented as percentages with SE.

COPD, chronic obstructive pulmonary disease; SE, standard error; NA, not available.

Figure 4. An example of joinpoint regression analysis for the estimation of the trend of prevalence of early COPD in males aged 40–49 years. COPD, chronic obstructive pulmonary disease.

Table 5. Joinpoint regression analysis for trend estimation of early chronic obstructive pulmonary disease.

	Total		Male		Female
	Coefficient	p	Coefficient	p	Coefficient	p
All participants
Joinpoint location (year)	2014		2014		2013
Slope 1	0.065	0.439	0.104	0.134	–0.157	0.639
Slope 2	–0.073	0.234	–0.136	0.028	0.071	0.422
Pack-year <10
Joinpoint location (year)	2013		2013		2013
Slope 1	–0.183	0.607	–0.367	0.53	–0.372	0.455
Slope 2	0.109	0.419	0.192	0.417	0.193	0.3
Pack-year ≥10
Joinpoint location (year)	2015		2015		–
Slope 1	0.078	0.613	0.096	0.583	–1.396	0.035
Slope 2	–0.168	0.162	–0.166	0.192	–	–
Current smokers
Joinpoint location (year)	2014		2014		2012
Slope 1	0.112	0.131	0.146	0.054	–0.605	0.681
Slope 2	–0.096	0.097	–0.111	0.068	0.185	0.433
Former smokers
Joinpoint location (year)	2016		2012		–
Slope 1	–0.006	0.928	0.336	0.265	–0.231	0.047
Slope 2	–0.282	0.245	–0.122	0.016	–	–
Never smokers
Joinpoint location (year)	2013		2015		2013
Slope 1	–0.074	0.717	0.077	0.714	–0.058	0.872
Slope 2	0.072	0.236	–0.072	0.831	0.063	0.507

COPD, chronic obstructive pulmonary disease.

Bold values denote statistical significance at the p < 0.05 level.