Handwashing and the Law of Diminishing Returns

IPs spend a lot of time monitoring and educating about handwashing. There are continuous debates about what the consequences should be for staff who are “caught” not washing their hands. One question that rarely is raised in Infection Control Committee meetings is whether there is an upper limit beyond which hand hygiene will no longer play a major role in HAI prevention. The answer can have profound effects on the amount of time and energy devoted to this one particular part of the IP role.

Two recent articles have questioned the relationship between increasing handwashing compliance and reduction of health care infections. Biggs, Shepherd and Kerr (2008) performed a mathematical analysis of the transmission of Staph by healthcare workers’ hands that became contaminated by patient contact. They concluded that a compliance levels (or imperfect hand hygiene) <50% were sufficient to stop outbreaks. They also concluded that the rate of increase in hand hygiene compliance was not associated with a similar decrease in infection transmission

Silvestri, Petros, Sarginson, et al (2005) conducted a literature review of 9 studies that looked at the relationship between hand hygiene compliance levels and actual infection rates. They concluded that [poor] handwashing can only account for 40% of transmission in intensive care units.

Why do these studies make sense in a time when hand washing is the first commandment of health care delivery? Both the literature and everyday observation provide some answers. First, glove use is becoming a universal practice. There are few studies that test how much hand contamination occurs with the use of gloves. Second, think of all of the environmental surfaces and healthcare equipment becomes contaminated and is used without cleaning. Stethoscopes, phones (both patient and clinician), bath basins, computer screens and on and on have been found to be contaminated. How effective are clean and gloved hands if contaminated equipment is used between patients without cleaning in between. I recently conducted a study in which we found that pens became contaminated within a single work shift. How many staff take pens into patients rooms, mark dressings and put the pen back into a pocket?

I think the time has come to take a harder look at housekeeping surfaces. I have found that most housekeepers want to do a good job but are hampered by a workload that allows only the most cursory of cleaning. It is about time that we stopped using precious resources on hand hygiene compliance and use them to provide more housekeepers with better equipment.

Beggs, C.B, Shepherd, S.J., and Kerr, K.G. (2008). Increasing the frequency of

handwashing by healthcare workers does not lead to commensurate reductions

in staphylococcal infections in a hospital ward. British Medical Journal of

Infectious Disease,8, 114. Available at: http:/www.biomedcentral.com/1471-

2334/8/114.

Silvestri, L., Petros, A.J., Sarginson, R.E., de la Cal, M.A.,Murray, A.E. and Saene, H.K.

(2005). Handwashing in the intensive care unit: a big measure with modest effects.

Journal of Hospital Infections, 59(3), 172 – 179.