Hospitalization in double-occupancy rooms and the risk of hospital-acquired influenza: a prospective cohort study.

Hospitalization in double-occupancy rooms and the risk of hospital-acquired influenza were assessed prospectively. The incidence was 2.0 for 100 patient-days in double- vs. 0.7 in single-occupancy rooms (p 0.028). The adjusted hazard ratio of hospital-acquired influenza was 2.67 (95% confidence interval 1.05-6.76) in patients hospitalized in double- compared to single-occupancy rooms.