Simplifying the WHO 'how to hand rub' technique: three steps are as effective as six-results from an experimental randomized crossover trial

Objectives: The World Health Organization (WHO) issued guidelines on hand hygiene recommending a six-step 'how to hand rub' technique for applying alcohol-based hand rub. However, adherence to all six steps is poor. We assessed a simplified three-step technique and compared it to the conventional WHO six-step technique in terms of bacterial count reduction on healthcare workers' hands.

Methods: Thirty-two participants were randomly assigned to clean their hands following the six-step 'how to hand rub' technique (WHO reference group) or a simplified three-step technique (intervention group). Assignments were reversed after 1 day. The degree of bacterial killing was assessed following the European norm for testing hand hygiene products. Hands were contaminated with Escherichia coli, and the mean logarithmic reduction in bacterial counts was compared between both techniques.

Results: Bacterial density before hand hygiene performance did not differ between the WHO reference group (median 6.37 log₁₀ CFU, interquartile range (IQR) 6.19-6.54) and the intervention group (median 6.34 log₁₀ CFU, IQR 6.17-6.60, p 0.513). After hand hygiene, the logarithmic reduction factor was higher in the intervention group (median 4.45, IQR 4.04-5.15) compared to the WHO reference group (median 3.91, IQR 3.69-4.62, p 0.021).

Conclusions: The WHO six-step 'how to hand rub' technique can be simplified to a 3-step procedure based on the reduction of bacterial counts on healthcare workers' hands achieved under experimental conditions. The proposed technique is easier to perform and could improve adherence to the execution of hand hygiene action.