Assessing the Hawthorne effect on hand hygiene compliance in an intensive care unit.

Background: The influence of the Hawthorne effect on hand hygiene compliance in an intensive care unit was assessed using covert and overt direct observation.

Methods: The observational study was conducted from February to November 2018 in a 24-bed adult intensive care unit in a 243-bed tertiary care hospital, in four periods (P): P-1, February 5-March 3, 29 h (covert) and P-2, March 15-April 16, 33 h (overt), prior to an educational campaign on hand hygiene; and P-3, August 27-September 28, 33 h (covert) and P-4, October 3-November 6, 35 h (overt), after the campaign. Three 20-min observation sessions were performed daily, randomly distributed in the morning, afternoon and evening shifts, including holidays and weekends.