From best to good: can we "right-size" approaches to reducing healthcare-associated infections?

From the Section of Infectious Disease and International Health, Dartmouth-Hitchcock Medical Center, Lebanon, and the Center for Leadership and Improvement, the Dartmouth Institute for Health Policy and Clinical Practice, Dartmouth Medical School, Hanover, New Hampshire. Received May 1, 2010; accepted May 3, 2010; electronically published July 1, 2010. Infect Control Hosp Epidemiol 2010; 31(8):784-785 2010 by The Society for Healthcare Epidemiology of America. All rights reserved. 0899-823X/2010/3108-0002$15.00. DOI: 10.1086/654002 Determining which infection control interventions should be implemented in a given situation is a constant challenge for those who work in healthcare epidemiology. The literature overflows with papers detailing successful outcomes associated with numerous interventions applied in a range of settings to a variety of patient populations. Taken as a whole, this literature suggests that there are many potential contributors to lowering infection rates. It seems intuitively obvious that not every intervention that has ever been shown to work must be implemented in every healthcare setting. However, too often, in an effort to identify “best practices,” guideline writers imply that there is indeed one “right size” that will fit all healthcare facilities. Although there probably are a handful of best practices (eg, hand hygiene before patient care or the use of prophylactic antibiotics just prior to certain surgical procedures), there are many more interventions that could be considered “good practices,” useful in some settings, unnecessary in others. A better fit might be achieved if healthcare epidemiologists were to select from among these to customize their infection prevention programs. Which good practices to choose likely depends on local context. In this issue of the journal, Fraser et al describe their experience controlling healthcare-associated infections (HAIs) due to Staphylococcus aureus in an intensive care unit at the Cleveland Clinic (Cleveland, Ohio). Their paper illustrates some of the useful information that can be derived from category II–III evidence, as well as some of the pitfalls that can limit the value of this type of evidence. The investigators targeted patients colonized with S. aureus for interventions designed to reduce or eliminate their bacterial burden. After establishing a baseline rate of colonization and infection among this patient population, their intention was to provide colonized patients with daily chlorhexidine baths and intranasal mupirocin. When they measured colonization and infection rates at the end of the intervention period, they were able to demonstrate lower rates of acquisition of S. aureus colonization and of ventilator-associated pneumonia (but not bloodstream infection) due to S. aureus. The authors concluded that the lower infection rates were likely the result of the interventions that they implemented. But were they? Although the investigators are appropriately careful not to generalize their findings to other settings, I would propose that they still go a little too far in linking their outcomes to their (intended) interventions. It is actually a strength of their study that allows me to say this: the authors provide us with information about how successfully they implemented the planned interventions. It turns out that mupirocin was dispensed to only 46% of the intended recipients, making it difficult to draw conclusions about its effect. Adherence to the chlorhexidine protocol was not measured, but because its use, like the use of mupirocin, was linked to a positive screening test result, one cannot assume that implementation of this intervention was 100% either. If the planned interventions were not fully implemented, why did already low infection rates drop even further during the intervention period? It could be that the selected interventions are effective and that full implementation would have resulted in even more striking results. Alternatively, the lower infection rates could have come about through unmeasured improvements related to the Hawthorne effect associated with the study itself. On the basis of the available information, we really cannot be sure. It seems obvious that unless an intended intervention is implemented, one cannot draw a valid conclusion that it is effective, much less that it is necessary. Yet there are many studies in the infection control literature in which just such conclusions are drawn, leading in some cases to misinterpretations regarding the necessity of certain interventions (such as the use of contact precautions) in preventing HAI.