Table S7. Effect of medium-term SHS exposure (yes vs. no) on outcomes in bivariate and multiple (adjusted) models based on FEV1/FVC < LLN.
| Outcome variables | Effect type† | Bivariate models | Multiple models‡ | |||
|---|---|---|---|---|---|---|
| Effect (95% CI) | P value | Effect (95% CI) | P value | |||
| Patient-centred outcomes | ||||||
| Chronic cough | OR | 2.20 (1.17–4.14) | 0.02* | 4.66 (1.39–15.58) | 0.01* | |
| Chronic sputum | OR | 1.71 (0.75–3.90) | 0.20 | 3.43 (0.84–13.98) | 0.08 | |
| Wheezing | OR | 1.93 (0.70–5.34) | 0.20 | 3.36 (0.83–13.64) | 0.09 | |
| Shortness of breath | OR | 1.78 (0.77–4.08) | 0.17 | 1.64 (0.50–5.41) | 0.41 | |
| Fair or poor general health | OR | 1.86 (0.83–4.20) | 0.13 | 0.85 (0.15–4.70) | 0.85 | |
| Worse health in the past year | OR | 1.17 (0.34–4.01) | 0.80 | 0.37 (0.12–1.13) | 0.08 | |
| Disease-centred outcomes | ||||||
| Outpatient visits ≥3 times per year | OR | 0.91 (0.36–2.30) | 0.83 | 0.46 (0.18–1.22) | 0.12 | |
| Hospitalization ≥1 time per year | OR | 1.85 (0.64–5.35) | 0.25 | 0.56 (0.12–2.56) | 0.45 | |
| Death during follow-up | HR | 1.25 (0.53–2.92) | 0.60 | 0.66 (0.27–1.65) | 0.37 | |
Data obtained from the National Health and Nutrition Examination Survey (2007–2012), National Center for Health Statistics. †, the reference category was the group without medium-term SHS exposure; ‡, multiple models were adjusted by age, gender, ethnicity, family income-to-poverty ratio grading, GOLD grading, smoking history, inhaled bronchodilators, and inhaled combination of bronchodilators and corticosteroids; *, statistical significance at the P<0.05 level. SHS, secondhand smoke; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; LLN, lower limit of normal; CI, confidential interval; OR, odds ratio; HR, Hazard Ratio; GOLD, Global Initiative for Chronic Obstructive Lung Disease.