Table 2.
Associations of Participant Characteristics with Having at Least One of Airflow Limitation, Chronic Cough/Phlegm, and Currently Treated Respiratory Diseases (Logistic Regression Analysis)
| (A) Participant Characteristics Other Than Comorbidities | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Variables | Total (N = 22,293) | Ever-Smokers (n = 10,981) | Never-Smokers (n = 11,212) | |||||||||
| Crude OR (95% CI) | p value | Adjusted OR (95% CI) | p value | Crude OR (95% CI) | p value | Adjusted OR (95% CI) | p value | Crude OR (95% CI) | p value | Adjusted OR (95% CI) | p value | |
| Age (per 10 years) | 1.79 (1.69–1.88) | <0.001 | 1.89 (1.77–2.01) | <0.001 | 1.93 (1.80–2.07) | <0.001 | 2.04 (1.86–2.23) | <0.001 | 1.72 (1.58–1.87) | <0.001 | 1.81 (1.65–1.99) | <0.001 |
| Sex (male) | 2.00 (1.77–2.26) | <0.001 | 1.42 (1.21–1.66) | <0.001 | 1.66 (1.32–2.10) | <0.001 | 1.06 (0.80–1.41) | 0.677 | 1.46 (1.22–1.74) | <0.001 | 1.41 (1.15–1.72) | <0.001 |
| Pack-years (per 10 pack-years) | — | — | — | — | 1.25 (1.20–1.29) | <0.001 | 1.09 (1.04–1.13) | <0.001 | — | — | — | — |
| BMI (per 1 kg/m2) | 1.00 (0.99–1.02) | 0.651 | 0.96 (0.94–0.98) | <0.001 | 0.98 (0.96–1.00) | 0.038 | 0.96 (0.94–0.99) | 0.003 | 1.01 (0.98–1.03) | 0.624 | 0.97 (0.94–1.01) | 0.102 |
| CRP (per 0.5 mg/dL) | 1.13 (1.07–1.20) | <0.001 | 1.08 (1.01–1.16) | 0.029 | 1.16 (1.07–1.27) | <0.001 | 1.11 (1.00–1.23) | 0.041 | 1.11 (1.02–1.20) | 0.015 | 1.05 (0.95–1.17) | 0.310 |
| CAT score (per 5 points) | 1.59 (1.52–1.67) | <0.001 | 1.69 (1.60–1.78) | <0.001 | 1.48 (1.40–1.57) | <0.001 | 1.67 (1.56–1.79) | <0.001 | 1.68 (1.55–1.81) | <0.001 | 1.72 (1.58–1.87) | <0.001 |
| Notes: Objective variable was having at least one of airflow limitation (FEV1/FVC < 70%), chronic cough and phlegm, and under treatment for respiratory disease. Among the 22,293 subjects, 100 had no smoking data. Adjusted odds ratios for age, sex, pack-years, BMI, CRP and CAT score were calculated by using these 6 explanatory variables (in never-smokers, 5 explanatory variables other than pack-years). Abbreviations: BMI, body mass index; CAT, chronic obstructive pulmonary disease assessment test; CI, confidence interval; CRP, C-reactive protein; OR, odds ratio. | ||||||||||||
| (B) Comorbidities | ||||||||||||
| Variables | Total (N = 22,293) | Ever-Smokers (n = 10,981) | Never-Smokers (n = 11,212) | |||||||||
| Crude OR (95% CI) | p value | Adjusted OR (95% CI) | p value | Crude OR (95% CI) | p value | Adjusted OR (95% CI) | p value | Crude OR (95% CI) | p value | Adjusted OR (95% CI) | p value | |
| Myocardial infarction | 1.99 (1.02–3.86) | 0.043 | 0.88 (0.43–1.80) | 0.725 | 2.04 (0.99–4.18) | 0.053 | 1.04 (0.48–2.26) | 0.922 | <0.01 (<0.01->999) | 0.949 | <0.01 (<0.01->999) | 0.945 |
| Angina pectoris | 1.93 (1.24–3.00) | 0.003 | 1.14 (0.72–1.79) | 0.573 | 1.61 (0.93–2.78) | 0.089 | 1.07 (0.60–1.89) | 0.826 | 2.10 (0.96–4.59) | 0.064 | 1.11 (0.50–2.46) | 0.797 |
| Cerebrovascular disease | 1.39 (0.79–2.47) | 0.257 | 0.85 (0.47–1.53) | 0.583 | 1.11 (0.53–2.31) | 0.778 | 0.77 (0.36–1.63) | 0.493 | 1.52 (0.55–4.22) | 0.419 | 0.86 (0.31–2.41) | 0.776 |
| Osteoporosis | 1.65 (1.09–2.51) | 0.018 | 1.23 (0.79–1.91) | 0.364 | 2.31 (0.87–6.11) | 0.092 | 0.90 (0.30–2.66) | 0.844 | 2.25 (1.40–3.59) | <0.001 | 1.40 (0.86–2.28) | 0.176 |
| Fracture | 1.96 (0.83–4.61) | 0.125 | 1.59 (0.65–3.90) | 0.313 | 2.90 (0.95–8.84) | 0.060 | 2.08 (0.62–6.92) | 0.234 | 1.51 (0.36–6.38) | 0.572 | 1.17 (0.28–4.97) | 0.833 |
| Depression | 0.87 (0.51–1.50) | 0.622 | 1.20 (0.69–2.07) | 0.525 | 0.57 (0.25–1.29) | 0.175 | 0.84 (0.36–1.93) | 0.677 | 1.50 (0.73–3.08) | 0.275 | 1.76 (0.85–3.65) | 0.130 |
| Anxiety disorder | 1.52 (0.93–2.49) | 0.092 | 1.87 (1.13–3.10) | 0.015 | 0.82 (0.36–1.89) | 0.642 | 0.96 (0.41–2.26) | 0.927 | 2.87 (1.56–5.28) | <0.001 | 2.13 (1.68–5.82) | <0.001 |
| Sleep disorder | 1.80 (1.33–2.43) | <0.001 | 1.49 (1.08–2.06) | 0.015 | 1.87 (1.24–2.81) | 0.003 | 1.35 (0.86–2.13) | 0.187 | 1.96 (1.25–3.10) | 0.004 | 1.70 (1.07–2.70) | 0.025 |
| Diabetes mellitus | 1.04 (0.83–1.32) | 0.724 | 0.64 (0.50–0.82) | <0.001 | 0.76 (0.56–1.02) | 0.065 | 0.50 (0.36–0.69) | <0.001 | 1.56 (1.06–2.30) | 0.025 | 1.06 (0.71–1.57) | 0.782 |
| Lung cancer | 4.28 (2.34–7.82) | <0.001 | 2.46 (1.31–4.60) | 0.005 | 4.53 (1.96–10.45) | <0.001 | 2.55 (1.06–6.10) | 0.036 | 4.61 (1.89–11.20) | <0.001 | 2.56 (1.03–6.34) | 0.043 |
Notes: Objective variable was having at least one of airflow limitation (FEV1/FVC < 70%), chronic cough and phlegm, and under treatment for respiratory disease. Among the 22,293 subjects, 100 had no smoking data. Adjusted odds ratios for each comorbidity was calculated by using 5 explanatory variables including each comorbidity, age, sex, pack-years and BMI (in never-smokers, 4 explanatory variables other than pack-years). In never smokers, all the participants with comorbid myocardial infarction did not have airflow limitation, chronic cough/phlegm or currently treated respiratory diseases.