Table 4. Risk of ILI by Vaccine Type and Health Behavior During Two Influenza Seasons (2006/2007, 2008/2009).

				Vaccine Type
				LAIV			TIV
	Total Study Population			All	ILI Diagnosis		All	ILI Diagnosis
	N	ILI	%	N	N	%	N	N	%	p	HR (95% CI)a
Overall	28,929	3936	13.61	22,734	3149	13.85	6195	787	12.70		0.98 (0.90–1.06)
Recent smoking history										0.099
Nonsmoker	20,974	2813	13.41	16,496	2228	13.51	4478	585	13.06		0.94 (0.85–1.03)
Smoking history	7955	1,123	14.12	6238	921	14.76	1717	202	11.76		1.09 (0.94–1.27)
Possible alcohol problems										0.209
No drinking problem	26,708	3669	13.74	21,079	2933	13.91	5629	736	13.08		0.96 (0.89–1.05)
Possible drinking problem	2221	267	12.02	1655	216	13.05	566	51	9.01		1.19 (0.86–1.63)
Exercise level										0.114
Moderate	20,345	2782	13.67	16,032	2209	13.78	4313	573	13.29		0.92 (0.84–1.01)
Minimal	3039	439	14.45	2334	348	14.91	705	91	12.91		1.08 (0.85–1.36)
High	1283	133	10.37	1007	108	10.72	276	25	9.06		1.12 (0.71–1.76)
Unknown	4262	582	13.66	3361	484	14.40	901	98	10.88		1.19 (0.96–1.48)

Abbreviations: CI, confidence interval; HR, hazard ratio; ILI, influenza-like illness; LAIV, live, attenuated influenza vaccine; TIV, trivalent inactivated influenza vaccine.

^aHazard ratio for each health behavior stratum is evaluated at the average level of other behaviors in the study population and adjusted for all other demographic covariates.