Variability in the Hawthorne Effect With Regard to Hand Hygiene Performance in High- and Low-Performing Inpatient Care Units

Objective.To determine the impact of known observers on hand hygiene performance in inpatient care units with differing baseline levels of hand hygiene compliance.Design.Observational study.Setting.Three inpatient care units, selected on the basis of past hand hygiene performance, in a hospital where hand hygiene observation and feedback are routine.Participants.Three infection control practitioners (ICPs) and a student intern observed hospital staff.Methods.Beginning in late 2005, the 3 ICPs, who were well known to the hospital staff, performed frequent, regular observations of hand hygiene in all 3 inpatient care units of the hospital, as part of routine surveillance. During the study period (January-May 2007), a student intern who was unknown to the hospital staff also performed observations of hand hygiene in the 3 inpatient care units. The rates of hand hygiene compliance observed by the 3 ICPs were compared with those observed by the student intern.Results.The 3 ICPs observed 332 opportunities for hand hygiene during 15 observation periods, and the student intern observed 355 opportunities during 19 observation periods. The overall rate of hand hygiene compliance observed by the ICPs was 65% (ie, in 215 of the 332 opportunities, the performance of proper hand hygiene by hospital staff was observed), and the overall rate of hand hygiene compliance observed by the student intern was 58% (ie, in 207 of the 355 opportunities, the performance of proper hand hygiene by hospital staff was observed) (P = .1). Both the ICPs and the student intern were able to distinguish between inpatient care units with a high rate of hand hygiene compliance (hereafter referred to as high-performing units) and those with a low rate (hereafter referred to as low-performing units). However, in the 2 high-performing units, the ICPs observed significantly higher compliance rates than did the student intern, whereas in the low-performing unit, both the ICPs and the student intern measured similarly low rates of hand hygiene compliance.Conclusions.Recognized observers are associated with higher rates of hand hygiene compliance, even in a healthcare setting where such observations have become routine. This effect (ie, the Hawthorne effect) is more pronounced in high-performing units and insignificant in low-performing units. The use of unrecognized observers may be important for verifying high performance but is probably unnecessary for documenting poor performance. Moreover, the Hawthorne effect may be a useful tool for sustaining and improving hand hygiene compliance.