TABLE 4.

Multivariable-adjusted hazard ratios^* for the association of body mass index^†, body mass index adjusted for waist circumference, and waist circumference adjusted for body mass index with lung cancer among current and former smokers, by level of smoking, in the Women's Health Initiative, 1998–2006

No. of cigarettes smoked per day and quintile of BMI‡ or WC‡	No. of cases		BMI				WC-adjusted BMI				BMI-adjusted WC
	Current smokers	Former smokers	Current smokers		Former smokers		Current smokers		Former smokers		Current smokers		Former smokers
			HR‡	95% CI‡	HR	95% CI	HR	95% CI	HR	95% CI	HR	95% CI	HR	95% CI
5–14	85	138
1			1.00	Reference	1.00	Reference	1.00	Reference	1.00	Reference	1.00	Reference	1.00	Reference
2			0.83	0.45, 1.53	1.45	0.82, 2.57	0.81	0.40, 1.63	1.45	0.74, 2.82	0.64	0.30, 1.35	0.68	0.33, 1.39
3			0.77	0.40, 1.50	0.93	0.49, 1.75	0.68	0.29, 1.62	0.86	0.38, 1.92	1.15	0.51, 2.56	1.23	0.59, 2.25
4			0.66	0.32, 1.37	0.72	0.36, 1.44	0.59	0.22, 1.63	0.63	0.24, 1.62	1.12	0.43, 2.96	0.93	0.39, 2.25
5			0.68	0.28, 1.62	1.70	0.91, 3.18	0.55	0.31, 1.44	1.31	0.47, 3.65	1.14	0.35, 3.73	1.31	0.48, 3.58
p for trend			0.25		0.31		0.28		0.79		0.67		0.47
15–24	178	248
1			1.00	Reference	1.00	Reference	1.00	Reference	1.00	Reference	1.00	Reference	1.00	Reference
2			1.34	0.89, 2.01	0.78	0.50, 1.21	1.46	0.92, 2.32	0.77	0.46, 1.27	0.74	0.46, 1.20	1.03	0.61, 1.74
3			0.72	0.44, 1.17	0.78	0.50, 1.21	0.74	0.39, 1.41	0.77	0.44, 1.35	0.70	0.39, 1.26	1.07	0.60, 1.92
4			0.69	0.41, 1.15	0.97	0.64, 1.48	0.62	0.29, 1.32	0.88	0.48, 1.63	0.98	0.50, 1.90	0.87	0.45, 1.69
5			0.65	0.35, 1.21	0.74	0.46, 1.18	0.51	0.20, 1.32	0.52	0.25, 1.07	1.14	0.48, 2.67	1.61	0.79, 3.27
p for trend			0.02		0.48		0.10		0.18		0.94		0.27
25–34	71	113
1			1.00	Reference	1.00	Reference	1.00	Reference	1.00	Reference	1.00	Reference	1.00	Reference
2			1.12	0.60, 2.08	0.69	0.33, 1.46	1.43	0.68, 2.99	0.56	0.25, 1.28	0.89	0.40, 1.95	1.16	0.47, 2.86
3			0.80	0.38, 1.70	0.85	0.43, 1.70	1.09	0.40, 2.98	0.61	0.26, 1.45	0.65	0.26, 1.64	1.78	0.70, 4.51
4			0.89	0.42, 1.88	1.24	0.64, 2.39	1.19	0.38, 3.73	0.86	0.33, 2.20	0.50	0.17, 1.48	1.64	0.58, 4.59
5			0.44	0.14, 1.32	1.08	0.54, 2.16	0.39	0.09, 1.80	0.76	0.26, 2.22	1.00	0.29, 3.48	1.60	0.51, 5.02
p for trend			0.13		0.34		0.45		0.99		0.57		0.41
≥35	50	162
1			1.00	Reference	1.00	Reference	1.00	Reference	1.00	Reference	1.00	Reference	1.00	Reference
2			0.58	0.23, 1.46	1.09	0.66, 1.78	0.42	0.14, 1.21	1.07	0.62, 1.86	1.33	0.45, 3.96	0.98	0.53, 1.80
3			0.70	0.28, 1.77	0.58	0.34, 1.01	0.22	0.06, 0.85	0.49	0.25, 0.96	0.89	0.22, 3.56	0.88	0.44, 1.77
4			1.10	0.47, 2.57	0.52	0.30, 0.92	0.19	0.05, 0.81	0.35	0.16, 0.75	4.69	1.20, 18.26	1.58	0.75, 3.31
5			0.60	0.22, 1.64	0.51	0.29, 0.90	0.09	0.02, 0.47	0.30	0.13, 0.71	8.85	1.75, 44.70	1.77	0.74, 4.21
p for trend			0.62		0.002		0.007		0.001		0.01		0.14

^*Adjusted for age (years—continuous), education (less than high school graduation, high school graduation, some college, college graduation, or postcollege), ethnicity (White, Black, or other), 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), study (Observational Study/Clinical Trial), and years of smoking (seven levels). In models for former smokers, age at quitting smoking (11 levels) was included.

^†Measured weight (kg) divided by the square of measured height (cm)².

^‡BMI, body mass index; WC, waist circumference; HR, hazard ratio; CI, confidence interval.