Determination of clinical and demographic predictors of laboratory-confirmed influenza with subtype analysis

BMC Infectious Diseases

Table 3 Multivariate regression of laboratory-confirmed influenza versus demographic and clinical variables for subjects 6–49 years

Variable	β estimate	OR (95% CI)	p value
Intercept term	−5.85		<.001
Age (years)	−0.00	1.00 (0.98–1.02)	.713
Sex	0.13		.606
Female		1.14 (0.70–1.84)
Male^a		1.0
Acute onset	1.18		<.001
≤3 days		3.26 (2.09–5.10)
>3 days^a		1.0
Fever	1.35		<.001
>38.0°C		3.84 (2.23–6.61)
≤38.0°C^a		1.0
Cough	3.87		<.001
Yes		47.99 (6.29–366.13)
No^a		1.0
Body aches	0.95		.001
Yes		2.59 (1.47–4.54)
No^a		1.0
Vaccinated	−1.10		.001
Yes		0.33 (0.18–0.62)
No^a		1.0

NOTE. CI, confidence interval; OR, odds ratio. Multivariate stepwise logistic regression was performed in the combined age group (n = 521). The reduced model is presented here (n = 523). Age and sex were retained in the final model despite not being statistically associated with the outcome. ^aReference category in regression model.