Table 2.
Multivariate Logistic Regression Models of Smoking Relapse Defined Prospectively in PLuSSa
| Variables | PR | Non-PR | OR | 95% CI | P Value |
|---|---|---|---|---|---|
| n | 267 | 1142 | |||
| Age (y, mean (SD)) | 57.9 (6.2) | 60.6 (6.9) | 0.64b | 0.50, 0.83 | 0.0005 |
| Cigs/day | 0.83 | 0.71, 0.98 | 0.026 | ||
| 1-19 Cigs/day | 79 (29.6) | 291 (25.5) | |||
| 20-29 Cigs/day | 120 (44.9) | 458 (40.1) | |||
| 30-39 Cigs/day | 46 (17.2) | 223 (19.5) | |||
| 40 or more Cigs/day | 22 (8.2) | 170 (14.9) | |||
| Time since quit (y, median (Q1, Q3)) | 1 (0, 4) | 5 (2, 8) | |||
| Spline 1 | <0.0001 | ||||
| Spline 2 | 0.039 | ||||
| Spline 3 | 0.24 | ||||
| Number of symptomsc | 1.21 | 1.01, 1.44 | 0.036 | ||
| None | 76 (28.5) | 408 (35.7) | |||
| 1 | 62 (23.2) | 248 (21.7) | |||
| 2 or more | 129 (48.3) | 486 (42.6) | |||
| Baseline COPD (yes, %) | 76 (28.5) | 394 (34.5) | 0.78 | 0.55, 1.10 | 0.16 |
Abbreviations: CI, confidence interval; COPD, chronic obstructive pulmonary disease; OR, odds ratio; PLuSS, the Pittsburgh Lung Screening Study; PR, prospective relapse; SD, standard deviation.
a
Area under ROC curve=0.785.
b
Odds ratio for every 10 years.
c
Baseline symptoms, including phlegm, wheezing, shortness of breath, and ankle swelling.