Table 2.

Association between influenza and pulmonary embolism.

	Odds ratios (OR) and 95% confidence intervals (95% CI)
	Crude OR (95% CI)	Adjusted OR (95% CI)
Influenza A	0.22 (0.03–1.67)	0.22 (0.03–1.72)
Influenza-like illness	1.28 (0.75–2.18)	1.16 (0.67–2.01)

Odds ratios (OR) on the association between influenza A infection and influenza-like illness score and pulmonary embolism with corresponding 95% confidence intervals (95% CI). Crude OR are adjusted for age, COPD (= chronic obstructive pulmonary disease) and asthma. We did not calculate the odds ratio for influenza B, because there were only few infected patients (0 in the case group, 3 in the control group).