On multivariate logistic regression, the only factor associated with a higher risk for pandemic infl uenza among all participants was younger age (OR 0.96, 95% CI 0.94-0.99) after adjustment for participant status (clinical vs. nonclinical), age, gender, hospital, seasonal infl uenza vaccination, confi rmed pandemic infl uenza, reported respiratory illness, community contact with infl uenza, oseltamivir prophylaxis, number of children in the household <18 years of age, and hours worked per week. On univariate analysis, the only factors that were signifi cantly associated with protection against infection in the clinical group were use of any mask (OR 0.16, 95% CI 0.03-0.97) and use of gloves (OR 0.09, 95% CI 0.02-0.5) for patients in droplet precautions. Adjusted odds ratios are shown in Table 3 .