kjhp Korean Journal of Health Promotion Korean J Health Promot 2234-2141 2093-5676 The Korean Society of Health Promotion and Disease Prevention 10.15384/kjhp.2014.14.4.155 kjhp-14-155 Original Article Effects of Smoking Status on Chronic Obstructive Pulmonary Disease Prevalence in Males 40 years and Older: Findings from the Korean National Health and Nutrition Examination Survey JungIn Sook 1 JungIn-Kyung 2 Department of Nursing, Chodang University, Muangun, Korea Department of Beauty Art, Honam University, Gwangju, Korea Corresponding author：In-Kyung Jung, PhD Department of Beauty Art, Honam University, 27 Sangmuminju-ro 6beon-gil, Seo-gu, Gwangju 502-791, Korea Tel: +82-62-370-8291, Fax: +82-62-370-8341 E-mail: jungik@honam.ac.kr 01 2014 20 01 2014 14 4 155 161 24082014 13112014 Copyright © 2014 The Korean Society of Health Promotion and Disease Prevention 2014 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Background

This is a study of the prevalence of chronic obstructive pulmonary disease (COPD), which shows high mortality worldwide, and the effects of smoking on COPD by using data from the Korea National Health and Nutrition Examination Survey V.

 Methods

FEV1/FEV6<0.73 was used as a diagnostic criterion of COPD. Frequency analysis for prevalence, descriptive statistics for general characteristics and ventilation rate according to age-specifications, and complex sample logistic regression analysis for the effect of smoking on COPD prevalence were used. IBM SPSS Statistics 21 Standard, Complex Samples for Medical Science(Windows) was used for data analysis(α =0.05).

 Results

Prevalence of COPD was 11.6±0.5% of Koreans in their forties or over, and 17.5±0.8% in males, and 6.2±0.5% in females. There was significant increase of COPD prevalence with age increment. Before adjusting for age and smoking index(SI), the COPD possibilities of past and current-smokers compared with non-smoking males were (odds ratio [OR] 2.112 [95% confidence interval [CI] 1.551–2.875]) and (OR 1.834 [95% CI 1.319–2.551]) respectively. After adjustments with age and SI, the COPD possibility of current-smoking was 2.099 (1.382–3.188) times higher and for past-smoking was 1.463 (1.012–2.115) times higher than non-smoking. The P-value of each group was significant. The regression coefficients (B) of current-smoking and past-smoking were 0.741 and 0.380 respectively. The prevalence of COPD increased 1.102 (1.090–1.115) times for every 1 year of age increase, and 1.012 (1.007–1.018) times for every 1 SI increase (P<0.001).

 Conclusions

After adjusting for age and SI, the prevalence of COPD in smokers was higher than non-smokers. And current-smoking had a higher OR and higher B than past-smoking.

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Prevalence of chronic obstructive pulmonary disease in KNHANES V

Characteristics Age group (year) Unweighted frequency COPD(FEV1/FEV6<0.73)
 non-COPD(FEV1/FEV6≥0.73)
Estimate±SEa Unweighted frequency Estimate±SEa Unweighted frequency
Total 40 and over 9,281 11.6±0.5 1,057 88.4±0.5 8,224
Male 40–49 1,204 6.3±0.8 72 93.7±0.8 1,132
  50–59 1,197 13.0±1.3 145 87.0±1.3 1,052
  60–69 993 27.1±1.8 262 72.9±1.8 731
  70–79 572 47.0±2.8 245 53.0±2.8 327
  80 and over 34 64.4±8.2 34 35.6±8.2 24
  Total 4,024 17.5±0.8 758 82.5±0.8 3,266
Female 40–49 1,411 2.2±0.5 28 97.8±0.5 1,383
  50–59 1,717 3.8±0.5 66 96.2±0.5 1,651
  60–69 1,304 9.0±1.1 98 91.0±1.1 1,206
  70–79 748 13.3±1.8 88 86.7±1.8 660
  80 and over 77 22.7±5.9 19 77.3±5.9 58
  Total 5,257 6.2±0.5 299 93.8±0.5 4,958

Abbreviations: KNHANES, Korea National Health and Nutrition Examination Survey; COPD, chronic obstructive pulmonary disease FEV1, forced expiratory volume in 1 second; FEV6, forced expiratory volume in 6 seconds; SE, standard error.

Values are presented N or estimate ±SE (%) unless otherwise indicated.

Respiratory and smoking characteristics of studied groupa

Characteristics Total
 FEV1/FEV6≥0.73
 FEV1/FEV6<0.73
 t/F Pb
Estimates ±SE Unweighted frequency Estimate ±SE Unweighted frequency Estimate ±SE Unweighted frequency
Age, y 54.9±0.2 4,024 53.0±0.2 3,266 63.6±0.6 758 –17.607 <0.001
FVC, L 4.2±0.0 4,024 4.3±0.0 3,266 4.0±0.0 758 7.433 <0.001
FVCp, % 92.1±0.2 4,020 92.3±0.3 3,262 90.7±0.6 758 2.346 0.019
FEV1, L 3.2±0.0 4,024 3.3±0.0 3,266 2.5±0.0 758 26.336 <0.001
FEV1p, % 89.9±0.3 4,020 92.7±0.3 3,262 77.1±0.7 758 21.642 <0.001
FEV1/FVC 0.8±0.0 4,024 0.8±0.0 3,266 0.6±0.0 758 44.168 <0.001
FEV6, L 4.0±0.0 4,024 4.1±0.0 3,266 3.6±0.0 758 12.110 <0.001
FEV1/FEV6 0.8±0.0 4,024 0.8±0.0 3,266 0.7±0.0 758 46.826 <0.001
Smoking duration, y 22.7±0.3 3,918 20.9±0.3 3,182 31.4±0.8 736 –12.845 <0.001
Smoking amount, pack 0.8±0.1 3,924 0.8±0.0 3,188 0.8±0.0 736 –2.519 0.012
Smoking index, pack∗y 21.0±0.4 3,917 19.6±0.4 3,181 28.2±1.0 736 –8.204 <0.001
Smoking status, %             2.227 0.026
 Current-smoking 41.8±1.0 1,449 82.5±1.2 1,162 17.5±1.2 287    
 Past-smoking 44.1±1.0 1,890 80.4±1.1 1,515 19.6±1.1 375    
 Non-smoking 14.1±0.7 600 89.6±1.3 525 10.4±1.3 75    

Abbreviations: FVC, forced vital capacity; FVCp, predicted value of FVC; FEV1, forced expiratory volume in 1 second; FEV1p, predicted value of FEV1; FEV6, forced expiratory volume in 6 seconds; SE, standard error.

Values are presented N or estimate±SE (%) unless otherwise indicated.

Calculated by CSGLM (complex sample general linear model).

FEV1/FVC and FEV1/FEV6 by age in males in KNHANES V

Characteristics Unweighted frequency (N) Weighted (%) FEV1/FVCa FEV1/FEV6a
Estimate±SE Pb Estimate±SE Pb
Age group       <0.001   <0.001
 40–49 (A) 1,204 38.3±1.1 0.793±0.002 (A≠B≠C≠D≠E)c 0.810±0.002 (A≠B≠C≠D≠E)c
 50–59 (B) 1,197 31.4±1.0 0.758±0.003   0.786±0.002  
 60–69 (C) 993 17.4±0.7 0.716±0.003   0.758±0.003  
 70–79 (D) 572 11.5±0.6 0.678±0.005   0.727±0.004  
 80-highest (E) 58 1.5±0.3 0.634±0.015   0.688±0.011  
 Total 4,024 100.0        

Abbreviations: KNHANES, Korea National Health and Nutrition Examination Survey; FVC, forced vital capacity; FEV1, forced expiratory volume in 1 second; FEV6, forced expiratory volume in 6 seconds; SE, standard error.

Values are presented as estimate±SE in liters.

Calculated by CSGLM (complex sample general linear model).

Calculated by repeated CSGLM.

Independent risk factors for chronic obstructive pulmonary disease in males in KNHANES V

Clinical variable B SE OR (95% CI) Pa
Smoking status       <0.001
 Current-smoking 0.607 0.168 1.834 (1.319–2.551)  
 Past-smoking 0.748 0.157 2.112 (1.551–2.875)  
 Non-smoking     1.000 (reference)  
Age group       <0.001
 40–49     1.000 (reference)  
 50–59 0.805 0.191 2.236 (1.537–3.252)  
 60–69 1.718 0.167 5.574 (4.018–7.732)  
 70–79 2.588 0.189 13.300 (9.175–19.281)  
 80 and over 3.302 0.389 27.163 (12.649–58.330)  
Smoking duration, y 0.051 0.004 1.052 (1.044–1.061) <0.001
Smoking amount, pack/day 0.199 0.077 1.221 (1.050–1.419) 0.010
Smoking index, pack∗y 0.022 0.002 1.022 (1.017–1.026) <0.001

Abbreviations: KNHANES, Korea National Health and Nutrition Examination Survey; B, coefficient; SE, standard error; OR, odds ratio; CI, confidence interval.

Calculated by CSLRA (complex sample logistic regression analysis).

Effects of smoking on chronic obstructive pulmonary disease prevalence in males in KNHANES V

Clinical variable Estimate±SE(%) Unweighted N B±SE OR (95% CI) Pa
Total 100.0 3,939      
Smoking status
 Current-smoking 41.8±1.0 1,449 0.741±0.213 2.099 (1.382–3.188) 0.001
 Past-smoking 44.1±1.0 1,890 0.380±0.188 1.463 (1.012–2.115) 0.043
 Non-smoking 14.1±0.7 600   1.000 (reference)  
Age, per 1-year increase     0.097±0.006 1.102 (1.090–1.115) <0.001
SI, per 1-pack∗year increase     0.012±0.003 1.012 (1.007–1.018) <0.001

Abbreviations: KNHANES, Korea National Health and Nutrition Examination Survey; B, coefficient; SE, standard error; OR, odds ratio; CI confidence interval; SI, smoking index as pack∗year.

Calculated by CSLRA (complex sample logistic regression analysis).