Table 3.
Results from Lung Health Study data analyses: full cohort (FC) analyses and auxiliary variable sampling and random sampling results averaged across 250 replicates. RS=random sampling, AVS=auxiliary variable sampling, SOR=sequential offsetted regressions, and IPW=inverse probability weighting with (known–by–design) weights 1/π(Zi)). We show logistic regression parameter estimates and standard errors (in parentheses) for the FC, and we show their average parameter and standard error estimates across 250 replicates for the RS and AVS designs. Models also included 9 dummy variables to adjust for differences across the 10 centers. For all analyses, GEE with a working independence correlation model was used.
| Covariate | FC | random sampling | AVS:SOR | AVS:IPW |
|---|---|---|---|---|
| COPD–Free analysis | ||||
| Time–varying covariates | ||||
| Current Smoker | −0.33 (0.06) | −0.34 (0.13) | −0.29 (0.11) | −0.34 (0.13) |
| Current Smoker (lag) | −0.35 (0.05) | −0.36 (0.11) | −0.37 (0.10) | −0.35 (0.11) |
| Study Year | −0.14 (0.01) | −0.15 (0.02) | −0.15 (0.02) | −0.14 (0.03) |
| Dust | −0.16 (0.06) | −0.16 (0.15) | −0.18 (0.13) | −0.15 (0.15) |
| Time–fixed covariates | ||||
| Female (vs male) | 0.28 (0.08) | 0.27 (0.18) | 0.27 (0.15) | 0.29 (0.17) |
| Baseline Age (per 10–year change) | −0.68 (0.06) | −0.68 (0.14) | −0.71 (0.12) | −0.70 (0.14) |
| Pack years (per 20–pack year change) | −0.09 (0.05) | −0.09 (0.12) | −0.07 (0.10) | −0.09 (0.12) |
| Cigarettes/day (per 10–cigs/day change) | −0.07 (0.03) | −0.07 (0.07) | −0.07 (0.06) | −0.07 (0.07) |
| Education (per 4–year change) | 0.01 (0.05) | 0.02 (0.12) | 0.03 (0.10) | 0.01 (0.12) |
| Baseline BMI (per 5 – kg/m2 change) | 0.23 (0.04) | 0.24 (0.10) | 0.19 (0.09) | 0.24 (0.10) |
| Chronic bronchitis | −0.22 (0.18) | −0.24 (0.43) | −0.43 (0.36) | −0.24 (0.41) |
| Asthma | −0.67 (0.25) | −0.74 (0.60) | −0.62 (0.50) | −0.70 (0.55) |
|
| ||||
| Severe COPD analysis | ||||
| Time–varying covariates | ||||
| Current Smoker | 0.34 (0.07) | 0.36 (0.15) | 0.35 (0.11) | 0.34 (0.15) |
| Current Smoker (lag) | 0.36 (0.06) | 0.37 (0.13) | 0.37 (0.09) | 0.37 (0.14) |
| Study Year | 0.19 (0.01) | 0.19 (0.02) | 0.18 (0.03) | 0.20 (0.03) |
| Dust | 0.04 (0.07) | 0.04 (0.17) | −0.03 (0.13) | 0.05 (0.17) |
| Time–fixed covariates | ||||
| Female (vs male) | −0.24 (0.09) | −0.26 (0.21) | −0.22 (0.16) | −0.26 (0.21) |
| Baseline Age (per 10–year change) | 0.69 (0.07) | 0.72 (0.16) | 0.69 (0.12) | 0.71 (0.16) |
| Pack years (per 20–pack year change) | 0.11 (0.05) | 0.12 (0.11) | 0.12 (0.09) | 0.12 (0.11) |
| Cigarettes/day (per 10–cigs/day change) | 0.04 (0.03) | 0.04 (0.07) | 0.01 (0.06) | 0.03 (0.07) |
| Education (per 4–year change) | −0.11 (0.06) | −0.12 (0.13) | −0.07 (0.10) | −0.11 (0.13) |
| Baseline BMI (per 5 – kg/m2 change) | −0.33 (0.06) | −0.34 (0.13) | −0.35 (0.10) | −0.35 (0.14) |
| Chronic bronchitis | 0.08 (0.18) | 0.08 (0.44) | 0.10 (0.33) | 0.11 (0.42) |
| Asthma | 0.80 (0.22) | 0.77 (0.52) | 0.68 (0.41) | 0.82 (0.49) |