TABLE 2.
Age- and multivariable-adjusted hazard ratios for the association of demographic and lifestyle characteristics with lung cancer in the Women's Health Initiative, 1998–2006
| Characteristic | No. of cases | Person-years of follow-up | Age-adjusted | Multivariable-adjusted* | ||
| HR† | 95% CI† | HR | 95% CI | |||
| Education | ||||||
| Less than high school graduation | 90 | 131,924 | 1.00 | Reference | 1.00 | Reference |
| High school graduation | 268 | 439,624 | 0.93 | 0.73, 1.17 | 0.93 | 0.72, 1.21 |
| Some college | 549 | 897,501 | 0.89 | 0.71, 1.11 | 0.87 | 0.68, 1.11 |
| College graduation | 143 | 251,118 | 0.82 | 0.63, 1.07 | 0.92 | 0.69, 1.23 |
| Postcollege education | 292 | 440,569 | 0.65 | 0.51, 0.83 | 0.76 | 0.58, 0.99 |
| Smoking status | ||||||
| Never smoker | 197 | 317,923 | 1.00 | Reference | 1.00 | Reference |
| Former smoker | 736 | 1,171,423 | 4.53 | 3.89, 5.28 | 4.34 | 3.69, 5.11 |
| Current smoker | 404 | 660,882 | 18.25 | 15.43, 21.57 | 17.10 | 14.26, 20.50 |
| Pack-years of smoking | ||||||
| None | 197 | 317,923 | 1.00 | Reference | 1.00 | Reference |
| >0–<20 | 231 | 360,418 | 2.23 | 1.85, 2.70 | 2.08 | 1.69, 2.55 |
| 20–<40 | 317 | 529,577 | 8.07 | 6.75, 9.64 | 7.96 | 6.59, 9.62 |
| 40–<60 | 292 | 475,458 | 17.29 | 14.43, 20.71 | 16.35 | 13.47, 19.86 |
| ≥60 | 278 | 428,263 | 22.95 | 19.12, 27.55 | 22.71 | 18.68, 27.60 |
| Alcohol consumption | ||||||
| Nondrinker | 69 | 117,265 | 1.00 | Reference | 1.00 | Reference |
| Former drinker | 292 | 449,656 | 2.61 | 2.01, 3.40 | 1.08 | 0.82, 1.41 |
| Current drinker | ||||||
| <1 drink/month | 146 | 223,141 | 2.03 | 1.52, 2.70 | 0.91 | 0.68, 1.22 |
| <1 drink/week | 272 | 464,296 | 2.22 | 1.71, 2.90 | 1.11 | 0.85, 1.46 |
| 1–<7 drinks/week | 336 | 539,768 | 2.21 | 1.71, 2.87 | 1.02 | 0.78, 1.34 |
| ≥7 drinks/week | 227 | 364,462 | 3.20 | 2.44, 4.19 | 1.00 | 0.76, 1.33 |
| Fruit intake (servings/day) | ||||||
| <0.82 | 362 | 603,590 | 1.00 | Reference | 1.00 | Reference |
| 0.82–<1.32 | 295 | 461,345 | 0.75 | 0.64, 0.88 | 1.05 | 0.89, 1.24 |
| 1.32–<2.02 | 244 | 409,381 | 0.59 | 0.50, 0.69 | 0.89 | 0.74, 1.06 |
| 2.02–<3.00 | 197 | 314,840 | 0.52 | 0.43, 0.62 | 0.87 | 0.71, 1.07 |
| ≥3.00 | 206 | 311,420 | 0.46 | 0.38, 0.54 | 0.85 | 0.68, 1.05 |
| p for trend | <0.0001 | 0.04 | ||||
| Physical activity (metabolic equivalents/week) | ||||||
| <1.38 | 310 | 478,363 | 1.00 | Reference | 1.00 | Reference |
| 1.38–<5.52 | 261 | 425,184 | 0.83 | 0.70, 0.98 | 0.99 | 0.83, 1.17 |
| 5.52–<11.69 | 261 | 405,951 | 0.80 | 0.68, 0.95 | 1.02 | 0.86, 1.22 |
| 11.69–<21.02 | 208 | 335,581 | 0.64 | 0.54, 0.76 | 0.89 | 0.74, 1.07 |
| ≥21.02 | 231 | 359,244 | 0.72 | 0.61, 0.86 | 1.06 | 0.88, 1.28 |
| p for trend | <0.0001 | 0.22 | ||||
| Body mass index‡ | ||||||
| <23.1 | 314 | 498,884 | 1.00 | Reference | 1.00 | Reference |
| 23.1–<25.6 | 311 | 516,999 | 0.98 | 0.84, 1.15 | 1.04 | 0.88, 1.23 |
| 25.6–<28.3 | 236 | 370,208 | 0.74 | 0.63, 0.88 | 0.77 | 0.64, 9.93 |
| 28.3–<32.2 | 265 | 411,730 | 0.85 | 0.72, 1.00 | 0.81 | 0.68, 0.98 |
| ≥32.2 | 227 | 377,170 | 0.79 | 0.67, 0.94 | 0.79 | 0.65, 0.96 |
| p for trend | 0.001 | 0.001 | ||||
Adjusted for age (years—continuous), smoking status (never, former, or current smoker), pack-years of smoking (none, >0–<20, 20–<40, 40–<60, or ≥60), education (less than high school graduation, high school graduation, some college, college graduation, or postcollege), ethnicity (White, Black, or other), use of hormone replacement therapy (never/ever), intakes of total fat (g/day), fruits (servings/day), vegetables (servings/day), alcohol (drinks/week), and total calories (kcal/day) (all continuous), physical activity (metabolic equivalents per week—continuous), and study (Observational Study/Clinical Trial).
HR, hazard ratio; CI, confidence interval.
Measured weight (kg) divided by the square of measured height (cm)2.