Table 3.

Univariate (^mOR) conditional regression analysis

	mOR	95 % CI	P
Vaccinations in 6 weeks before index date
Seasonal influenza vaccination 2010–2011	3.9	1.6–9.9	0.004
Other vaccinations	3.5	0.2–55.8	0.38
Infections in 6 weeks before index date
Influenza-like illness (ILI)	8.7	4.2–18.3	<0.001
Upper respiratory tract infection (URI)	4.1	2.2–7.7	<0.001
Gastrointestinal infection (GI)	12.3	4.7–32.2	<0.001
Chronic comorbidity
Malignancy	1.2	0.6–2.4	0.65
Immunocompromised	6.1	1.6–23.3	0.008
Autoimmune disorders	2.7	1.1–7.0	0.035
Epstein-Barr virus	2.2	0.7–6.4	0.15
Other conditions in 6 months before index date
Surgery	1.0	0.4–2.5	0.98
Influenza-like illness (ILI)	4.1	2.3–7.1	<0.001
Upper respiratory tract infection (URI)	2.7	1.6–4.7	<0.001
Gastrointestinal infection (GI)	5.9	2.9–11.8	<0.001
Vaccination
Seasonal influenza vaccination 2010–2011	1.6	0.9–2.7	0.12
Seasonal influenza vaccination >6 weeks	0.9	0.4–1.6	0.64
Other vaccinations	1.0	0.2–5.6	0.98