Who goes in and out of patient rooms? An observational study of room entries and exits in the acute care setting.

•A large observation study of 14,876 patient room entries and exits in 16 hospitals was done performed•Entries and exits are attributed to health care personnel (HCP) and non-HCP.•HCP accounted for 83.6% of all patient roomentries and exits (95% CI confidence interval, 81.3%–87.6%).•HCP have the greatest impact on entries and exits in pediatric and adult units.•The data are useful to hospitals trying automated hand hygiene monitoring systems.