Reference: N Engl J Med. 2023 Nov 9;389(19):1766
Practice Point: Universal decolonization of nursing home residents with chlorhexidine and nasal iodoform is associated with a reduction in hospitalization due to infection.
EBM Pearl: Clustered participants are likely to have similar exposures, treatments, and thereby, outcomes. For some trials such as those involving nursing home residents, randomizing in clusters rather than individuals reduces confounding.
Infections that occur in nursing homes are a major cause of both hospitalizations and death, and there is strong evidence that nursing homes serve as a repository for multidrug resistant organisms (MDROs). One way to combat the rise of MDROs involves decolonization with topical antiseptics. Until recently, evidence for decolonization was mostly for known MDRO carriers or high risk situations such as certain preop or ICU patients. However, a recent trial published in the NEJM found that universal decolonization of nursing home residents in Southern California led to significantly fewer infections and hospitalizations.
Investigators randomized 28 nursing homes with 28,956 residents to either universal decolonization with chlorhexidine and nasal iodoform or routine care for 18 months. Prior to the interventions, 18 months of baseline data was collected for both groups and those facilities assigned to decolonization underwent an additional 4-month phase-in period for staff training. Decolonization was performed using chlorhexidine (2% chlorhexidine cloth for bed bathing or 4% wash for showering) upon admission and during all routine bathing, in addition to nurse-administered nasal iodoform (10% povidone-iodine) twice daily for the first 5 days after admission, then every other week thereafter. The primary and secondary outcomes were hospitalization due to infection or for any reason, respectively.
An intention-to-treat analysis demonstrated a significant reduction in hospitalizations in the decolonization group. Compared to routine care, the NNT to prevent one infection-related hospitalization was 9.7, and the NNT to prevent one hospitalization for any reason was 8.9.
Given these results, universal decolonization for nursing home residents seems like a worthwhile pursuit. We commend the authors for using a cluster-randomized design. This design is optimal when the target of the intervention is a group or a system as opposed to an individual. This helps to avoid confounding given participants in a cluster (residents of the same nursing home) are likely to be treated similarly and have similar exposures (like an influenza outbreak) and therefore are likely to have similar outcomes.
While we don’t necessarily doubt the efficacy of universal decolonization, we do wonder about its effectiveness- what the magnitude of effect would be under real-world circumstances. Most nursing homes are not exactly loaded down with extra nursing support, and this intervention requires additional resources. To that point, 3 of 14 nursing homes in the decolonization group dropped out due to lack of resources to carry out the intervention. Similarly, adherence to nasal iodophor was only 60%, which is likely at least partially explained by the requirement for nurse administration (rather than nursing assistants). While the switch to a chlorhexidine wash may be feasible, nasal decolonization as carried out in this trial may pose more of a practical challenge. Nevertheless, this study makes a fairly strong case for the efficacy of universal decolonization of nursing home residents. We just still need to figure out how to implement an effective intervention with the resources available.
For more information, see the topic Methicillin-resistant Staphylococcus aureus (MRSA) in DynaMed.
DynaMed EBM Focus Editorial Team
This EBM Focus was written by Nicole Jensen, MD, Family Physician at WholeHealth Medical. Edited by Alan Ehrlich, MD, Executive Editor at DynaMed and Associate Professor in Family Medicine at the University of Massachusetts Medical School; Katharine DeGeorge, MD, MS, Senior Deputy Editor at DynaMed and Associate Professor of Family Medicine at the University of Virginia; Dan Randall, MD, Deputy Editor at DynaMed; Vincent Lemaitre, PhD, Medical Editor at DynaMed; Elham Razmpoosh, PhD, Postdoctoral fellow at McMaster University; Hannah Ekeh, MA, Senior Associate Editor at DynaMed; and Jennifer Wallace, BA, Associate Editor at DynaMed.