Table 3. Effect of medium-term SHS exposure (yes vs. no) on outcomes in bivariate and multiple (adjusted) models.
| Outcome variables | Effect type† | Bivariate models | Multiple models‡ | |||
|---|---|---|---|---|---|---|
| Effect (95% CI) | P value | Effect (95% CI) | P value | |||
| Patient-centred outcomes | ||||||
| Chronic cough | OR | 2.55 (1.17–5.57) | 0.02* | 3.57 (1.22–10.40) | 0.02* | |
| Chronic sputum | OR | 1.56 (0.69–3.52) | 0.28 | 1.78 (0.54–5.85) | 0.34 | |
| Wheezing | OR | 1.99 (1.07–3.73) | 0.03* | 1.78 (0.72–4.40) | 0.20 | |
| Shortness of breath | OR | 1.94 (0.94–3.98) | 0.07 | 1.56 (0.63–3.85) | 0.33 | |
| Fair or poor general health | OR | 2.24 (1.19–4.21) | 0.01* | 1.53 (0.61–3.85) | 0.36 | |
| Worse health in the past year | OR | 1.35 (0.60–3.08) | 0.46 | 0.77 (0.28–2.06) | 0.59 | |
| Disease-centred outcomes | ||||||
| Outpatient visits ≥3 times per year | OR | 1.01 (0.54–1.88) | 0.98 | 0.63 (0.31–1.29) | 0.20 | |
| Hospitalization ≥1 time per year | OR | 1.15 (0.40–3.35) | 0.79 | 0.39 (0.09–1.72) | 0.21 | |
| Death during follow-up | HR | 1.21 (0.62–2.36) | 0.56 | 0.72 (0.34–1.54) | 0.39 | |
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. CI, confidential interval; GOLD, Global Initiative for Chronic Obstructive Lung Disease; HR, hazard ratio; OR, odds ratio; SHS, secondhand smoke.