Improving hand hygiene compliance is a major goal of all healthcare epidemiology programs.Reference Boyce and Pittet 1 However, despite the importance of monitoring compliance and improving practices, currently available measurement methods are limited. Gold standard methods of hand hygiene measurement can be subject to the Hawthorne effect and are time-consuming (direct observation)Reference Srigley, Furness, Baker and Gardam 2 and/or prohibitively expensive (electronic or video monitoring systems).Reference Srigley, Lightfoot, Fernie, Gardam and Muller 3
A third strategy for monitoring hand hygiene compliance is the measurement of product usage. This strategy is attractive because it can be broadly applied across all areas of a medical facility, does not require additional staff, is not subject to the Hawthorne effect, and is less expensive than other methods of measurement.Reference Boyce 4 Prior studies, however, have provided mixed results regarding the effectiveness of this method for monitoring compliance, particularly in intensive care units (ICUs).Reference Marra, Moura, Paes, dos Santos and Edmond 5 , Reference McGuckin, Waterman and Govednik 6 Thus, we sought to assess the utility of product usage data for monitoring hand hygiene rates in our institution and to determine whether product usage has stronger correlation with direct observation outside of the ICU, where monitoring can be more challenging and time-consuming.
METHODS
Study Design
Hand hygiene compliance was measured by direct observation with trained observers in the ICUs and in the medical and surgical wards at a large, academic, tertiary-care center from October 2011 through June 2014. These ICUs were diverse: medical ICUs (including 1 with a focus on immunocompromised patients), surgical ICUs, and a coronary care unit.
Trained observers included trained hand hygiene observers and nursing, research, and infectious diseases trainees. Direct observations were recorded for room entry and exit for at least 30 minutes to obtain a mean hand hygiene compliance rate for a given unit or ward and were performed at least 3–4 times per quarter in all ICUs and 3–4 times per year in all medical and surgical wards.
Hand Hygiene Compliance Measurement Strategies and Definitions
Product usage data were also collected and evaluated by collecting empty liquid soap and alcohol-based hand sanitizer containers and counting them on a weekly basis. Hand hygiene events per container were calculated as the volume of product used divided by the standard aliquot per hand hygiene event (1 cm3 per event for alcohol-based hand sanitizer and 1.7 cm3 per event for liquid soap). The rate of product usage (RPU) was calculated as the number of hand hygiene events per patient per day for each unit and quarter; the expected number of hand hygiene events was adjusted for ward type. The product usage percentage (PUP) was calculated as the RPU divided by a standardized rate from a prior internal study of observed room entry and exits by healthcare workers, presented as a percentage and adapted from previously published methods.Reference McGuckin, Waterman and Govednik 6
Statistical Analysis
Each of the 3 parameters were collected by fiscal quarter and stratified by unit type: direct observation (DO), RPU, and PUP. Linear regression was used to evaluate the correlation between different compliance metrics. Results were stratified by unit type.
RESULTS
During the 15 fiscal quarter study periods, data on all 3 hand hygiene parameters were available for 105 unit-quarter periods, including 7 ICUs (69 quarters) and 8 medical or surgical wards (36 quarters) (Figure 1). During the unit-quarter periods studied, the median patient occupancy was 660 patient days per quarter in the ICUs (range, 514–1,167) and 2,412.5 patient days per quarter in the medical and surgical wards (range, 1,783–2,965).
FIGURE 1 Hand hygiene parameters over time, stratified by unit type (medical and surgical wards versus intensive care units). NOTE. Rate of product usage is in units of hand hygiene events per patient day.
Correlation Between Direct Observation and Product Usage Measures
Hand hygiene compliance was relatively stable in the ICU settings and decreased slightly in the medical and surgical wards during the study period. Among included ICUs and medical and surgical wards, compliance with hand hygiene opportunities measured by direct observation ranged from 38.3% to 95.5% (median, 82.5%). Compliance measured by the RPU ranged from 31.7 to 437.0 hand hygiene events per patient day (median, 196.8), and the PUP ranged from 26.0% to 100% (median, 84.2%). All measures of hand hygiene compliance were generally higher in the ICUs compared to medical/surgical wards (Figure 1).
There was a correlation of moderate value between hand hygiene compliance measured by direct observation and RPU and PUP across the whole facility (RPU: r2=0.539, P<.001; PUP: r2=0.532, P<.001). After stratifying by unit type, a moderate correlation between direct observation and RPU and PUP was found for the medical and surgical wards (RPU: r2=0.430, P<.001; PUP: r2=0.504, P<.001), but there was a poor correlation in the ICUs (RPU: r2=0.029, P=.16; PUP: r2=0.007, P=.50) (Figure 2).
FIGURE 2 Correlation between hand hygiene compliance measured by direct observation and product usage parameters. The trend lines represent a linear regression for each of the 4 data sets to aid visualization. NOTE. DO, direct observation; RPU, rate of product usage; PUP, product usage percentage; ICUs, intensive care units.
DISCUSSION
Our findings suggest that measuring product usage may be a useful tool for monitoring trends in hand hygiene compliance, particularly in non-ICU settings. In healthcare settings with many wards, measurement of product usage may be a time- and cost-efficient adjunct to already established methods for monitoring hand hygiene compliance. Our study adds to current knowledge by including a large number and variety of ward settings, including evaluating product usage metrics on both high- and low-performing units.
The weak correlation found between measures of product usage and direct observation in the ICU aligns with prior investigations.Reference Marra, Moura, Paes, dos Santos and Edmond 5 This finding suggests that, due to the inherently crude nature of the metric, product usage may not be useful for identifying small fluctuations in compliance, as may occur in high-performing units, but that in other clinical settings, product usage provides crude—but useful—information about compliance trends.
All studies of hand hygiene compliance monitoring methods are limited by the “gold standard” metric, typically direct observation.Reference Boyce 4 Recent studies called this “gold standard” designation into question,Reference Morgan, Pineles and Shardell 7 , Reference Filho, Marra and Magnus 8 as direct observation may be influenced by the well-described Hawthorne effect. Passive measures, including product usage, are not subject to these behavioral fluctuations in clinical practice.Reference Srigley, Furness, Baker and Gardam 2 , Reference Hagel, Reischke and Kesselmeier 9 Other limitations of direct observation include (1) that it may not work well in settings where there are fewer healthcare-worker–patient interactions and (2) that interactions may occur behind closed doors and curtains, limiting the ability of observers to collect high-quality data. Product usage metrics are not subject to these challenges and, thus, may provide useful information about what is occurring during these unobserved interactions. Electronic methods of monitoring hand hygiene compliance are also not subject to the Hawthorne effect or unobserved interactions, but they are considerably more expensive than product usage measures and may not be feasible in many healthcare settings.Reference Srigley, Lightfoot, Fernie, Gardam and Muller 3 , Reference McGuckin, Waterman and Govednik 6
Our study had several limitations. First, complete data were not available for all units for all quarters. However, because all units were sampled at least once yearly during the study period, this likely did not significantly impact our findings. Second, our study was completed in a single academic center, and results may vary in different clinical settings. Third, the units that were included in the study, including the ICUs, were diverse. Product usage metrics were adjusted for expected number of events on these units, however, likely did not fully account for the heterogeneity inherent in these interactions. This may have biased results against product usage metrics in some cases. Finally, direct observation was used as the “gold standard,” although this method is known to be imperfect.
In conclusion, the measurement of product utilization rates is a practical and inexpensive method for estimating hand hygiene compliance, particularly in non-ICU settings that are difficult to monitor using direct observation. In the ICU, the utility of this method is limited, and other metrics should be considered.
ACKNOWLEDGMENTS
We thank Roger Araujo-Castillo, MD, MCID, for his assistance with data collection and analysis.
Financial support: W.B.-E. is supported by a Veterans Integrated Service Network (VISN)-1 Career Development Award.
Potential conflicts of interest: All authors report no potential conflict of interest.
