Liquid versus gel handrub formulation: a prospective intervention study

Health care workers' (HCWs') hands play a key role in the patient-to-patient transmission of microbial pathogens, and hand hygiene is the primary measure to prevent cross-infection in hospitals [1]. Improvement in hand hygiene practices reduces health care-associated infection [2] and the burden of disease in the community [3, 4]. However, the impact of hand hygiene in reducing infections relies on multiple factors, including the type of hand-cleansing agent used [1, 2]. Hand antisepsis with alcohol-based handrubs has many advantages over handwashing with soap and water: it requires less time, acts faster, and is more efficacious, more convenient, and better tolerated by HCWs' skin [2].

Studies have shown that handrubbing contributes to enhanced compliance [5‐7]. However, the use of a product also depends on dermal tolerance and user acceptability with consideration of parameters such as fragrance, drying speed, and skin feeling following application [8, 9]. It has been suggested that among alcohol-based handrubs, gels could be associated with better skin care properties and dermal tolerance than liquid formulations, thus leading to more acceptable products and to potentially better compliance [10‐13]. To our knowledge, there is no published study suggesting that adherence is higher when using gels rather than liquid formulations. We aimed to assess whether the introduction of a gel formulation would result in increased compliance with hand hygiene. A secondary objective was to compare the user acceptability and skin tolerance of the two formulations.

From March to July 2004, 379 observation sessions were performed (mean duration, 14.3 ± 8.9 minutes). Characteristics of the observation sessions and opportunities for hand hygiene across the two periods are shown in Table 1. The imbalance in the number of opportunities observed in the morning and afternoon across the study periods was not planned and occurred by chance. There were very few changes in ICU staff during the two periods; during phase II, two nurses and one nursing assistant left the ICU and one nurse was recruited. The proportion of nurses and nursing assistants who believed that they had been observed for hand hygiene compliance was 70% (56/80) and 69% (57/82) during phases I and II, respectively (p = 0.95). As calculated by the 7-point self-assessment scale to measure a modification of HCWs' hand-cleansing practice patterns, the mean scores were 3.1 ± 2 and 3.1 ± 1.8 during phases I and II, respectively (p = 0.75). Overall, the mean numbers of opportunities per hour were 15.7 ± 9.2 for nurses, 9.6 ± 4.3 for physicians, 10.9 ± 5.8 for nursing assistants, and 13.9 ± 8 for other HCWs.

Compliance varied with type of care: before respiratory tract care, 35.6%; before intravenous or arterial catheter care, 30.3%; before direct patient contact, 34.9%; before digestive tract care, 16.7%; before wound care, 70.4%; before handling clean material, 78%; and before urinary tract care, 25% (p < 0.001). A significant difference in compliance was observed across HCW categories: 39.1% among nurses, 27.1% among physicians, 31.1% among nursing assistants, and 13.9% among other HCWs (p = 0.027). However, it did not vary according to the intensity of patient care as assessed by the mean number of opportunities per hour (fewer than 10, 10 to 14, more than or equal to 15): 36.4%, 38.4%, and 35.1%, respectively (p = 0.14). Compliance was 33.3% (118/354) when the patient was isolated versus 37.8% (304/803) when he/she was not (p = 0.23). Compliance improved significantly when the alcohol-based formulation was available in the HCW's pocket: 35.3% (380/1,074) versus 50.6% (42/83) (p = 0.035). On average, compliance was higher in the morning than in the afternoon: 41.2% (266/646) versus 30.5% (156/511) (p = 0.001).

Table 2 compares compliance with hand hygiene between the two study phases. Overall, compliance increased from 32.1% during phase I to 41.2% during phase II (p = 0.035) (Table 2). In multivariate analysis, use of a gel formulation was associated with improved compliance, although the association did not reach statistical significance (Table 3). Importantly, pocket carriage of the alcohol-based handrub was associated with increased compliance. Of note, workload (as estimated by the number of opportunities for hand hygiene per hour) was not a predictor of compliance in multivariate analysis and did not confound the association between study phase and compliance and was therefore removed from the final model.

Eighty HCWs (66 nurses and 14 nursing assistants) participated in the skin tolerance evaluation during phase I, and 82 (68 nurses and 14 nursing assistants) during phase II (Table 4). Mean user acceptability scores for the liquid and gel formulations were 39.1 ± 7.3 and 40 ± 7.6, respectively (p = 0.44). Based on self-assessment, observer assessment, and the measurement of epidermal water content, the gel performed significantly better than the liquid formulation (Table 4). At the end of phase II, 47 HCWs (57%) rated the gel as better than the liquid formulation, 13 (16%) as equivalent to the liquid formulation, whereas 22 (27%) considered the gel formulation to be inferior.

Evaluation of the effect of a gel versus a liquid formulation on hand hygiene adherence and skin health is a key issue [8, 9]. Personal comfort and the likelihood that better tolerance will lead to better product acceptance and improved compliance support the importance of a healthy skin barrier [8, 9]. Because the liquid and gel formulations tested differed only by the addition of a gelling agent, observed differences in our study cannot be associated with the active ingredient.

Prospective observation of hand hygiene by a single observer is the most accurate means to assess compliance, and a comprehensive evaluation of skin condition was also performed. Overall compliance with hand hygiene recommendations was rather low but within the range observed in other studies [9], particularly those that were conducted in critical care and that focused on indications before patient care or contact [9, 14, 15, 18]. As previously reported, compliance varied according to HCW category and was lower among physicians than nurses [7, 14, 18]. Introduction of the gel formulation was associated with improved compliance among nurses but not among physicians, nursing assistants, and other HCWs. Importantly, immediate access to alcohol-based handrubs was the stronger predictor of compliance. Availability of a handrub at the point of care, whether liquid or gel, increased compliance independently of the type of formulation, time of day, professional category, and other confounders.

Reported reasons for poor HCW compliance with hand hygiene include skin irritation [8, 19, 20]. This issue is of particular relevance in critical care, where the need for hand hygiene is high [14, 18]. Our results show that the acceptability of the gel formulation was very high and that HCWs' skin condition improved during the study phase when the gel formulation was in use. No case of significant skin damage was observed for either product. Sustainability is a critical issue of hand hygiene promotion strategies, and user acceptability and skin tolerance of handrubs are key enabling factors [7, 9, 21].

Self- and observer-assessment variables as sensitive and reliable indicators of product acceptability were similar to those in earlier studies [16, 21]. All studies on skin tolerance, whether performed with volunteers or HCWs, showed that alcohol-based formulations, either liquid or gel, were much better tolerated than handwashing with antimicrobial or non-antimicrobial soap. Our study suggests that the gel formulation tested is better tolerated than the corresponding liquid formulation. Studies of the effects of alcohol-based products on HCWs' skin have been performed on volunteers with normal skin in a non-clinical setting [21‐24]. They were, therefore, less representative of field conditions that are characterized by the multifactorial interplay between skin integrity, skin flora, and individual attitudes [25‐28].

Our study was not designed to evaluate the microbiological effectiveness of the gel formulation. Although the limited efficacy of some alcohol-based hand gels has been reported [22, 29], the gel formulation used in this study, in contrast to earlier test products [29], meets the European Norm (EN)1500 standard for alcohol-based handrubs within 30 seconds.

There are several limitations to this study. First, because the HCWs and the observer were not blinded, assessments could have been biased. However, the Corneometer^® and the TEWL allowed objective measurement. Furthermore, except for TEWL data that did not show a difference between the two phases, all methods used to assess HCWs' skin hand condition yielded concordant results. Similarly, Winnefeld and colleagues [25] reported that TEWL was less sensitive than self-assessment at detecting a difference in skin tolerance. Second, HCWs may have changed their behavior because they were being observed. Observation bias is likely to increase compliance estimates. However, in each study phase, a similar proportion of HCWs felt that they had been observed, thus arguing against a major impact of observation on overall results [30]. Also, we cannot rule out that the improvement in compliance was due to the availability of a new formulation with a Hawthorne effect. Only repeated observations at a later time point could demonstrate a sustained improvement, but unfortunately, the observations in this study could not be extended longer than twonths following the change of formulation. Importantly, both the use of the gel formulation and the facilitated access to a handrub independently predicted improved compliance. Furthermore, considering the excellent tolerance of both formulations and user preferences, both formulations are currently proposed to ICU staff. Third, seasonal variation may have contributed to the better skin condition observed during phase II (between May and July), when the gel formulation was used, although only very low temperatures have been shown to have a significant impact on skin condition [31]. Fourth, generalizability of study results requires additional testing among other HCW populations, in other health care settings, and with other handrubs. Finally, the study was not powered to assess differences in infection rates.

This is the first study to compare the use of an alcohol-based liquid versus a gel formulation on hand hygiene compliance in daily patient care. The gel was associated with better skin condition, superior acceptance, and a trend toward improved compliance as compared to the liquid formulation. Immediate access to the handrub was the strongest predictor of compliance. Whether our study findings are generalizable to other gel formulations and whether the observed improvement in hand hygiene would result in a decrease in health care-associated infection remain to be determined.