Table 4.

Multiple regression models for lung cancer incidence, WIHS and MACS combined.

	All years (1984-2011)			HAART era (1995-2011)
	IRR	95% CI	p-value for interaction with cohort*	IRR	95% CI	p-value for interaction with cohort*
MACS vs. WIHS	0.59	0.27-1.29		0.54	0.23-1.25
Calendar period
1984 - 2000	1
1995 - 2000				1
2001-2011	0.80	0.42-1.53	0.52	0.82	0.41-1.64	0.61
Age
<40	1			1
40-49	3.27	1.09-9.82	0.76	3.95	0.89-17.59	NE**
50-59	7.04	2.25-22.07	0.90	8.51	1.85-39.07	NE**
60 and older	11.52	3.23-41.09	0.78	15.98	3.15-80.98	NE**
Black vs. non-Black Race	1.86	0.98-3.54	0.65	1.83	0.93-3.60	0.61
IDU (ever vs. never)	0.98	0.53-1.80	0.59	1.02	0.54-1.95	0.48
Education (≤ high school vs. > high school)	2.29	1.20-4.39	0.25	1.95	0.96-3.98	0.44
BMI (per 10 unit increase)	0.70	0.40-1.20	0.86	0.67	0.38-1.19	0.56
Pack-years of smoking
<10	1			1
10-30	4.75	1.62-13.96	0.14	4.69	1.59-13.85	0.16
>30	11.09	3.72-33.11	0.35	8.73	2.85-26.73	0.15
HIV and AIDS
HIV-uninfected	1			1
HIV+, AIDS-free	1.79	0.80-4.03	0.75	1.71	0.64-4.57	0.74
HIV+, Prior AIDS (not pneumonia)	0.93	0.39-2.22	0.08	0.82	0.32-2.07	0.14
HIV+, Prior AIDS pneumonia	3.56	1.67-7.61	0.22	3.51	1.61-7.67	0.08
Nadir CD4 (< 200 vs. >=200) ***	1.37	0.71-2.63	0.13	1.46	0.73-2.92	0.03
HAART (experienced vs. naïve) ***	0.72	0.34-1.52	0.80	0.74	0.32-1.67	0.60

BMI = body mass index; CI = confidence interval; HIV+ = HIV-infected; HIV- = HIV-uninfected; IDU = injection drug use; IRR = incidence rate ratio; NE = not evaluable.

^*The p-value for an interaction between the given covariate and cohort tests whether the effect of the covariate differs between MACS and WIHS.

^**Not evaluable because no lung cancers were diagnosed in MACS participants younger than 40 years old during the HAART era.

^***The nadir CD4 and HAART experience effects correspond only to HIV-infected participants.