Commentary

Nosocomial infection is a major cause of morbidity in hospitals. Approximately 10% of patients develop hospital acquired infection, and infected patients incur about 3 times the costs of uninfected patients.^1–,² Handwashing is promoted as the single most effective means of preventing infections, but maintaining adherence to handwashing regimens has proved problematic.³ Hand rubs may be an alternative to handwashing, and the studies by Girou et al and Parienti et al add to the growing evidence about the effectiveness of handrubbing with alcohol based solutions compared with standard hygiene methods.

Girou et al conducted a trial involving permanent and temporary staff, as well as nursing assistants and nursing students. Participants were observed, a factor that may have improved compliance with hand hygiene. Despite this, 65% of handwashing procedures lasted <30 seconds, which is insufficient time to obtain optimum decontamination. The inadequacy of time devoted to handwashing is likely to have contributed to the difference in contamination rates. The time spent handrubbing after patient procedures was obviously sufficient for decontamination, reinforcing the practical implications of the result. The duration of reduced contamination and the effect of this reduction on patient outcomes were not evaluated. Bacterial contamination of hands during routine patient care is a useful surrogate outcome, but ideally a trial should focus on meaningful outcomes, such as nosocomial infection.

The study by Parienti et al did focus on a meaningful patient outcome (ie, SSIs), but examined the use of an alcohol based hand rub as a surgical scrub in a different context. Teaching and non-teaching hospitals were involved, and various surgical procedures were included. The main concern in interpreting this study’s findings is that the study centres (cluster) were randomised, not the patients. Although randomising by cluster is legitimate, clusters may be quite different, and this can affect outcomes. For instance, teaching and non-teaching hospitals differ in the complexity of patients and the experience of members of the surgical team (many of whom may still be in training). These differences may cause differential rates of SSI among clusters, which typically inflate the numbers required in a cluster trial compared with a trial that randomises by individual patient. It is a common error, as in this study, to randomise by cluster, but to analyse by individual, and such an error leads to inaccurately smaller p values or narrower confidence intervals. Cluster randomised trials should report baseline differences and treatment effects by cluster, allowing readers to interpret just how different clusters are. While the study by Parienti et al is an intriguing trial, whether hand rubs and handwashing are truly equivalent remains unclear.

Parienti et al also examined compliance with time devoted to the 2 hand hygiene protocols in a subset of procedures. Adherence was poor in both groups, but similar to the findings of Girou et al, compliance was worse in the handwashing group (44% v 28%). The argument for no difference between protocols would be strengthened if SSI rates were similar when adherence to protocols was high.

Overall, the findings of these 2 studies tend to support the conclusion that alcohol based preparations are at least equivalent to, if not more effective than, traditional hand hygiene methods. Practitioners in all settings could use these studies as a basis for considering the introduction of alcohol based hand rubs. However, before applying these findings, factors such as cost and clinician acceptance should be considered. Anecdotal reports of dermatitis and eczema being relieved when healthcare workers switched to alcohol based rubs conflict with entrenched views that hand rubs are likely to increase such occupational hazards. If hand rubs are introduced, practitioners need to consider how they can best promote compliance with the new protocol and evaluate changes in nosocomial infection rates.