Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Characteristics of the study population
| Variable | Cases (n = 582) | Controls (n = 582) |
| Age (years) | 61.3 ± 9.4 | 60.2 ± 9.6 |
| Sex | ||
| Male | 467 (80.2)a | 467 (80.2) |
| Female | 115 (19.8) | 115 (19.8) |
| Smoking statusb | ||
| Current | 387 (66.5) | 297 (51.0) |
| Former | 85 (14.6) | 147 (25.3) |
| Never | 110 (18.9) | 138 (23.7) |
| Pack-yearsc | 40.0 ± 17.7 | 34.1 ± 17.8 |
a Numbers in parenthesis, percentage.
b P < 0.001.
c In current and former smokers, P < 0.001
