Associations of living with a smoker and COPD outcomes in SPIROMICS
| Linear regression models | Absolute difference | 95% CI | p Value |
|---|---|---|---|
| 6 MWD, m | −7.68 | (−23.50 to 8.15) | 0.341 |
| FEV1% predicted | −2.13 | (−4.87 to 0.62) | 0.129 |
| SGRQ score | 3.10 | (0.99 to 5.21) | 0.004 |
| SF12 GH score | −1.53 | (−2.90 to −0.16) | 0.029 |
| CAT score | 1.43 | (0.52 to 2.35) | 0.002 |
| mMRC score | 0.07 | (−0.05 to 0.20) | 0.223 |
| Ease of Cough and Sputum score in past day | 0.76 | (0.34 to 1.19) | <0.0001 |
| % emphysema | 0.35 | (−0.92 to 1.55) | 0.573 |
| % gas-trapping | 0.06 | (−1.65 to 1.88) | 0.946 |
| Pi 10 (all airways) | 0.16 | (0.03 to 0.29) | 0.020 |
| Airway dimensions (fifth generation airways) | |||
| Wall area percentage | 0.431 | (0.023 to 0.840) | 0.039 |
| Wall area | −0.79767 | (−1.64367 to 0.04832) | 0.065 |
| Lumen area | −1.08644 | (−2.00936 to −0.16352) | 0.021 |
| Lumen diameter | −0.0799 | (−0.1697 to 0.0098) | 0.081 |
| Logistic regression models | OR | 95% CI | p Value |
| Nocturnal symptoms | 1.17 | (0.87 to 1.57) | 0.295 |
| Any wheezing | 1.16 | (0.86 to 1.54) | 0.325 |
| Chronic cough | 1.41 | (1.06 to 1.87) | 0.019 |
| Chronic productive cough | 1.71 | (1.28 to 2.30) | <0.0001 |
| Exacerbation risk in past year | 1.11 | (0.81 to 1.51) | 0.511 |
| Severe exacerbation risk in past year | 1.51 | (1.04 to 2.17) | 0.029 |
| Poisson models | RR | 95% CI | p Value |
| Exacerbations experienced over follow-up | 1.04 | (0.84 to 1.30) | 0.696 |
| Severe exacerbations experienced over follow-up | 1.11 | (0.82 to 1.52) | 0.497 |
Bold indicates statistically significant findings at P<0.05 level. Adjusted for age, gender, race, FEV1% predicted (except for analysis of FEV1% predicted), education level, current smoking status, oxygen use and pack-years smoked. Measures of airway dimensions additionally adjusted for total lung volume achieved at CT. Poisson models of exacerbations and severe exacerbations over follow-up additionally adjusted for follow-up time.
6 MWD, 6 min walk distance; CAT, COPD assessment test; mMRC, modified Medical Research Council questionnaire; RR, relative risk; SF12 GH, Medical outcomes short-form 12-item questionnaire general health score; SGRQ, St George's Respiratory Questionnaire; SPIROMICS, subpopulations and intermediate outcomes of COPD Study.