from Srigley et al. 2014
published in BMJ Qual Saf. 23(12):974-80
DOI 10.1136/bmjqs-2014-003080

Quantification of the Hawthorne effect in hand hygiene compliance monitoring using an electronic monitoring system: a retrospective cohort study

The Hawthorne effect very much influences the staff’s hand hygiene behaviour during observations

The retrospective cohort study was conducted in two organ transplant wards of an academic acute care hospital over a period of 8 months. The electronic monitoring system was installed in both units and comprised mobile tags worn by 60 employees. A network of wireless receivers installed in patient rooms, corridors and above all soap and hand disinfectant dispensers recorded movements, locations and the proximity of the tags to each other. Additionally, the system recorded how often the individual dosing dispensers were activated. During the last 3.5 months of the study, hand hygiene compliance was also assessed by direct observation in both wards (except in the patient rooms). The auditors also wore tags to document the location and time of observation. For data analysis, the frequency of activation per hour of dispensers within the auditor’s eyesight (exposed) was compared to the frequency of use of dispensers in corridors not visible to the auditor (unexposed). The comparison was done with three unexposed groups, each with different locations and times of data collection. The median frequency of activation of exposed dispensers in corridors was 3.75 per hour. Unexposed dispensers in corridors reached values of 1.48 (group 1), 1.07 (group 2) and 1.50 (group 3). The results show that the exposed dispensers were used significantly more often than those of the three comparison group. In patient rooms (no direct observation of hand hygiene behaviour), this effect was not observed.