This retrospective cohort study was conducted in two organ transplant wards of an academic acute care hospital over a period of 8 months. The objective was to investigate whether the presence of hand hygiene auditors was correlated with an increase in hand hygiene events. An electronic real-time location system (RTLS) was used to record time stamps of hand hygiene events performed by healthcare workers (HCWs). Each time the lever of dispensers was pushed an event was recorded. Auditors were equipped with electronic tags and their spatial proximity to dispensers was established when a tag was detected by electronic receivers. The data of auditors proximity to dispensers was systematically converted into the notion of being visible to HCWs and thus exposing them to observation. Auditors and HCWs were both blinded to the objective of the study. The frequencies of hand hygiene events per dispenser were measured by the RTLS and compared for dispensers within sight of auditors and three different control groups not exposed to auditors. Group 1: unexposed area, same time period of audit, control for temporal factors. Group 2: same area, 1-3 weeks prior to audit, control for variance in workload. Group 3: same area, 1-5 min prior to observation, control for reverse causation bias. For dispensers visible to auditors a significantly higher rate (3.75/dispenser/h) was found compared to all control groups (group 1: 1.48, group 2: 1.07 and group 3: 1.50/dispenser/h).
Quantification of the Hawthorne effect in hand hygiene compliance monitoring using an electronic monitoring system: a retrospective cohort study.
The Hawthorne effect significantly influences the HCWs hand hygiene behaviour during observations.