Healthcare workers’ hand hygiene rates were found to be three times higher when auditors were visible to healthcare workers than when there were no auditors present, according to a study in a major Canadian acute-care hospital.
The study examined the Hawthorne effect, also known as observation bias – the tendency of people to change their behavior when they are aware of an observer – using an electronic monitoring hand hygiene system in real-time, eliminating many of the biases inherent to human observation. Ultrasound “tags” on soap dispensers transmitted a signal to a nearby receiver each time the levers were pushed, and a time-stamped hand hygiene wash was recorded in a central data base.
Two inpatient units in University Health Network were electronically monitored, with 60 healthcare workers volunteering to be part of a study of the electronic monitoring system. Auditors did not announce their presence during audits but wore white lab coats. Hand hygiene dispenses were electronically measured while the auditors were visible, and were compared to the same locations prior to the arrival of the auditors at one, two and three weeks before the audit, as well as to a different area of the unit not visible to the auditor. Auditors typically did not go into patient rooms, so separate handwashing rates were determined for dispensers inside patient rooms and those in hallways. Twelve audits were included between November 2012 and March 2013.
The study found that there was an approximately three-fold increase in the rate of hallway handwashes per hour among healthcare staff when an auditor was visible (3.75 per hour), compared to a location where the auditor was not visible (1.48 per hour) and to the previous weeks (1.07 per hour). Handwashing rates with the auditor present were compared to separate groups at different time periods and locations to ensure that the differences found were not due to hand hygiene patterns that could be attributable to time of day or location. In each instance, the handwashing rates were significantly higher when the auditors were present, with the increase occurring after the auditors’ arrival, suggesting that the arrival of the auditor triggered the increase in hand hygiene.
“The magnitude of what we found calls into question the accuracy of directly observed hand hygiene rates and the usefulness of measuring and reporting them,” says Gardam, an associate professor of medicine at the University of Toronto. “That said, human auditing of hand hygiene has been helpful to draw attention to this important preventative measure—we just can’t stop focusing on it because our posted rates are not nearly as high as we think they are.”