Table 2.
Demographic and baseline smoking characteristics in relation to baseline prevalent PD as defined by at least 1 data source
| Characteristic | Baseline PD |
P value | |||
|---|---|---|---|---|---|
| PD (n = 60) |
no PD (n = 5,828) |
||||
| n | % | n | % | ||
| Age at baseline | 0.002 | ||||
| 65–74 years | 27 | 45.0 | 3,867 | 66.4 | |
| 75–85 years | 29 | 48.3 | 1,740 | 29.9 | |
| >85 years | 4 | 6.7 | 221 | 3.8 | |
| Male sex | 37 | 61.7 | 2,458 | 42.2 | 0.002 |
| Education | 0.26 | ||||
| <HS | 14 | 23.3 | 1,718 | 29.6 | |
| HS | 14 | 23.3 | 1,606 | 27.6 | |
| >HS | 32 | 53.3 | 2,487 | 42.8 | |
| African American | 3 | 5.0 | 921 | 15.8 | 0.02 |
| Smoking status | 0.12 | ||||
| Never | 34 | 56.7 | 2,704 | 46.4 | |
| Former | 21 | 35.0 | 2,423 | 41.6 | |
| Current | 5 | 8.3 | 695 | 11.9 | |
| Total pack-years | 0.21 | ||||
| Never smoker | 34 | 56.7 | 2,704 | 48.0 | |
| 1st quartile (0–13) | 9 | 15.0 | 856 | 15.2 | |
| 2nd quartile (14–27) | 3 | 5.0 | 660 | 11.7 | |
| 3rd quartile (28–49) | 8 | 13.3 | 515 | 9.1 | |
| 4th quartile (>50) | 6 | 10.0 | 898 | 15.9 | |
| Years since quitting | 0.08 | ||||
| Never smoker | 34 | 56.7 | 2,704 | 47.0 | |
| ≥30 | 7 | 11.7 | 626 | 10.9 | |
| 20–29 | 4 | 6.7 | 579 | 10.1 | |
| 10–19 | 8 | 13.3 | 595 | 10.4 | |
| <10 | 3 | 3.3 | 549 | 9.6 | |
| Current smoker | 5 | 8.3 | 695 | 12.1 | |
HS = High school. Numbers may not add up to column total due to missing values; p values assessed by Pearson's χ2 test for dichotomous categories, Fisher's exact test for categorical variables with small numbers, score test for linear trend for ordinal variables; pack-years: quartiles of total pack-years determined among non-PD smokers.