Evaluation of the effectiveness of hand hygiene guidelines or recommendations on the ultimate outcome, i.e. the HCAI rate, is certainly the most accurate way to measure the impact of improved hand hygiene, but it represents a very challenging activity. Indeed, guideline implementation should not be evaluated per se but in relation to the availability of clear instructions on how to translate it into practice and, ideally, the existence of related tools and impact of their implementation. As an illustration, in a sample of 40 hospitals in the USA, Larson and colleagues found that although most HCWs were aware of the hand hygiene guidelines with alcohol-based handrub available in all facilities, a multidisciplinary implementation programme was conducted in only 44.2% of the hospitals.728 The impact was quite disappointing: mean hand hygiene compliance rates were no higher than 56.6%, and the correlation of lower infection rates with higher compliance was demonstrated only for bloodstream infections. The authors concluded that a real change following guideline dissemination is not achievable unless fostered by factual multidisciplinary efforts and explicit administrative support.
Difficulties to deal with this challengig issue depend firstly on the diversity of methodologies used in available studies, and this is well reflected in the very different conclusions that can be drawn from systematic reviews on the topic.887,888
The lack of scientific information on the definitive impact of improved hand hygiene compliance on HCAI rates has been reported as a possible barrier to appropriate adherence with hand hygiene recommendations. However, there is convincing evidence that improved hand hygiene through multimodal implementation strategies can reduce infection rates. In addition, although not reporting infection rates, several studies showed a sustained decrease of the incidence of multidrug-resistant bacterial isolates and patient colonization following the implementation of hand hygiene improvement strategies.428,655,687,701 Failure to perform appropriate hand hygiene is considered the leading cause of HCAI and spread of multi-resistant organisms, and has been recognized as a significant contributor to outbreaks.
At least 20 hospital-based studies of the impact of hand hygiene on the risk of HCAI have been published between 1977 and June 2008 ().60,61,121,181,182,195,196,489,494,645,657,659,663,667,713–718,852 Despite study limitations, most reports showed a temporal relation between improved hand hygiene practices and reduced infection and cross-transmission rates.
Association between improved adherence with hand hygiene practice and health care-associated infection rates (1975– June 2008).
Maki195 found that HCAI rates were lower when antiseptic handwash was used by HCWs. Doebbeling and colleagues659 compared hand antisepsis using a chlorhexidine-containing detergent to a combination regimen that permitted either handwashing with plain soap or use of an alcohol-based handrub. HCAI rates were lower when the chlorhexidine-containing product was in use. However, because relatively little of the alcohol rub was used during periods when the combination regimen was in operation and because adherence to policies was higher when chlorhexidine was available, it was difficult to determine whether the lower infection rates were attributable to the hand hygiene regimen used or to the differences in HCW compliance with policies.
A study by Larson and colleagues713 found that the frequency of VRE infections, but not MRSA, decreased as adherence of HCWs to recommended handwashing measures improved. This strategy yielded sustained improvements in hand hygiene practices. The intervention lasted eight months, and a follow-up survey six months after the end of the intervention showed a sustained improvement in hand hygiene practices. More recently, several studies demonstrated a clear impact of improved hand hygiene on MRSA rates.489,494,718 In a district hospital in the United Kingdom, the incidence of hospital-acquired MRSA cases significantly decreased after a successful hand hygiene promotion programme.489 Similarly, in Australia, a hospitalwide, multifaceted programme to change hand hygiene culture and practices led to a 57% reduction of MRSA bacteraemia episodes as well as a significant reduction of the overall number of clinical isolates of MRSA and ESBL-producing E. coli and Klebsiella spp.494 The programme was subsequently expanded to another six health-care institutions and then to the entire state of Victoria. After 24 months and 12 months of follow-up, respectively, MRSA bacteraemia and the number of MRSA clinical isolates significantly decreased both in the 6 pilot hospital and statewide (see ).719 In another study, the intervention consisted of the hospitalwide introduction of an alcohol-based gel and MRSA surveillance feedback through charts.718 Significant reductions of MRSA bacteraemia and MRSA central line-associated bacteraemia were observed hospitalwide and in the ICU, respectively, with a follow-up of 36 months. In this study, however, it is difficult to define the actual role of hand hygiene to reduce MRSA bacteraemia, because charts were a strong component of the intervention and, at the same time general infection control measures were intensified and the use of antibiotic-coated central venous catheters was initiated in the ICU.
In 2000, a landmark study by Pittet and colleagues60 demonstrated that implementing a multidisciplinary programme to promote increased use of an alcohol-based handrub led to increased compliance of HCWs with recommended hand hygiene practices and a reduced prevalence of HCAI. Individual bottles of handrub solution were distributed in large numbers to all wards, and custom-made holders were mounted on all beds to facilitate access to hand antisepsis. HCWs were also encouraged to carry a bottle in their pocket. The promotional strategy was multimodal and involved a multidisciplinary team of HCWs, the use of wall posters, the promotion of bedside handrubs throughout the institution, and regular performance feedback to all HCWs (see http://www.hopisafe.ch for further details on methodology). HCAI rates, attack rates of MRSA cross-transmission, and consumption of handrub were measured in parallel. Adherence to recommended hand hygiene practices improved progressively from 48% in 1994 to 66% in 1997 (P <0.001). While recourse to handwashing with soap and water remained stable, the frequency of handrubbing markedly increased over the study period (P <0.001), and the consumption of alcohol-based handrub solution increased from 3.5 litres to 15.4 litres per 1000 patient-days between 1993 and 1998 (P <0.001). Importantly, increased recourse to handrubbing was associated with a significant improvement in compliance in critical care,334 suggesting that time constraint bypassing was critical. The increased frequency of hand antisepsis was unchanged after adjustment for known risk factors of poor adherence. During the same period, both overall HCAI and MRSA transmission rates decreased (both P <0.05). The observed reduction in MRSA transmission may well have been affected by both improved hand hygiene adherence and the simultaneous implementation of active surveillance cultures for detecting and isolating patients colonized with MRSA.889 Follow-up evaluation 8 years after the beginning of the programme revealed continuous improvement with hand hygiene practices, increased recourse to alcohol-based handrub, and stable HCAI rates; it also highlights the cost– effectiveness of the strategy.61 The experience from Geneva’s University Hospitals constitutes the first report of a hand hygiene campaign demonstrating a sustained improvement over several years; some recent further studies reported a positive impact of hand hygiene promotion with a prolonged follow-up (up to 3 years).494,714,717,718
More recently, a number of studies assessed the effectiveness of hand hygiene improvement to prevent HCAI in neonatal care. Following the implementation of hand hygiene multimodal strategies, Lam and colleagues648 and Won and colleagues714 demonstrated a significant decrease of overall HCAI rates in neonatal ICUs, whereas Pessoa-Silva and colleagues657 observed only a decrease in very low-birth-weight neonates (). A significant reduction of HCAI was also observed in adult ICU patients in a hospital in Argentina.716 Other investigations showed an impact of improved hand hygiene on specific types of HCAI such as rotavirus715 and surgical site infections in neurosurgery717 (). Furthermore, a recent review of the literature related to the effectiveness of handwashing against SARS transmission concluded that nine of 10 epidemiological studies showed a protective effect of hand hygiene, but this result was only significant in three in a multivariate analysis.890
In several other studies in which hand hygiene compliance was not monitored, multidisciplinary programmes that involved the introduction of an alcohol-based handrub were associated with a decrease in HCAI and cross-transmission rates.429,489,645,735 The beneficial effects of hand hygiene promotion on the risk of cross-transmission have also been reported in surveys conducted in schools or day-care centres,454,891–896 as well as in community settings.248,249,449,754,815,830,897–900
While none of the studies conducted in the health-care setting represented randomized controlled trials, they provide substantial evidence that increased hand hygiene compliance is associated with reduced HCAI rates. Indeed, only very few studies concluded that hand hygiene promotion had no impact on HCAI. A very early study from Simmons and colleagues showed that interventions aimed at improving handwashing practices in ICUs failed to improve them substantially and therefore to reduce HCAI.667 A very recently published two-year, prospective, controlled cross-over trial by Rupp and colleagues has attracted much attention, including from the lay press. The authors observed that a significant and sustained improvement in hand hygiene adherence following the introduction of an alcohol-based handrub did not lead to a substantial change in device-associated infection rates and infections due to multidrug-resistant pathogens.707 Nevertheless, it is crucial to note that although the study was, in general, well-designed and conducted, it presents key limitations that have led to harsh criticism following its publication,901–903 including lack of screening for cross-transmission, lack of statistical power, and use of an alcohol-based handrub that fails to meet the EN 1500 standards for antimicrobial efficacy.
Methodological and ethical concerns make it difficult to set up randomized controlled trials with appropriate sample sizes that could establish the relative importance of hand hygiene in the prevention of HCAI. The studies so far conducted, although semi-experimental and of good quality in most cases, could not determine a definitive causal relationship owing to the lack of statistical significance, the presence of confounding factors, or the absence of randomization. Given that multimodal strategies are the most preferred methods to obtain hand hygiene improvement,60,713,719,728 additional research on the relative effectiveness of the different components of these strategies would be very helpful to successful achievement of a sustainable impact.809,904
The unique large, randomized controlled trial to test the impact of hand hygiene promotion clearly demonstrated reduction of upper respiratory pulmonary infection, diarrhoea, and impetigo among children in a Pakistani community, with positive effect on child health.249,449 Although it remains important to generate additional scientific and causal evidence for the impact of enhanced adherence with hand hygiene on infection rates in health-care settings, these results strongly suggest that improved hand hygiene practices reduce the risk of transmission of pathogenic microorganisms.
