Table 3.

Comparison of ARI cases with matched hospital controls: analysis of vaccination status, underlying illness and other potential risk factors

			ARI cases vs. matched hospital
Variable	Cases (151)		Controls (246)		MOR (95% CI)	p
	N	%	N	%
Pandemic influenza vaccination	150	7	246	7	1.0 (0.4-2.5)	0.94
Seasonal influenza vaccination 2009/10	150	31	237	22	1.7 (1.1-2.8)	0.03
Seasonal influenza vaccination 2008/09	144	22	239	24	0.8 (0.4-1.5)	0.51
Seasonal influenza vaccination 2007/08	142	19	239	22	0.6 (0.4-1.7)	0.63
Pneumococcal vaccine	131	15	211	5	4.3 (1.5-11.8)	0.005
Pandemic influenza vaccine offered by employer	148	10	245	20	0.4 (0.2-0.8)	0.01
Any chronic underlying illness	152	67	246	57	4.5 (1.9-10.4	0.001
Any chronic lung disease	151	26	246	6	12.9 (4.5-36.4)	<0.0001
COPD	150	16	246	10	1.9 (1.0-3.6)	0.05
Asthma	151	16	246	10	2.1 (1.0-4.3)	0.05
Chronic bronchitis	152	35	244	18	3.4 (1.9-6.1)	<0.0001
Cardiovascular disease	152	39	245	30	1.9 (1.1-3.2)	0.02
Immunosuppression	146	15	246	0.4	35.2 (4.7-262.5)	0.001
BMI ≥31	151	21	244	24	0.9 (0.5-1.4)	0.54
Frailty	151	9	246	6	1.8 (0.8-4.0)	0.18
≥ 3 physician visits in past year	151	55	242	53	1.0 (0.7-1.6)	0.88
≥ 1 hospitalization in past year	152	30	245	34	0.9 (0.5-1.4)	0.57
Current smoker	152	44	246	47	0.9 (0.6-1.3)	0.53
>20 packyears vs. non-smoker	152	32	246	31	1.3 (0.7-2.3)	0.41
Alcohol: ≥ 1 drink/week	150	55	234	63	0.7 (0.4-1.0)	0.07
Children in household	152	38	246	19	2.7 (1.6-4.3)	<0.0001
Public transport (> = 3x/week) vs. none	152	41	244	44	0.9 (0.6-1.4)	0.52
Owns car	152	53	243	60	0.8 (0.5-1.1)	0.18
Completion of at least Grade 10	149	66	239	77	0.6 (0.4-0.9)	0.02
Private health insurance	152	15	244	19	0.6 (0.3-1.1)	0.11