Chlorhexidine versus routine bathing to prevent multidrug-resistant organisms and all-cause bloodstream infections in general medical and surgical units (ABATE Infection trial): a cluster-randomised trial

Abstract

Background: Universal skin and nasal decolonisation reduces multidrug-resistant pathogens and bloodstream infections in intensive care units. The effect of universal decolonisation on pathogens and infections in non-critical-care units is unknown. The aim of the ABATE Infection trial was to evaluate the use of chlorhexidine bathing in non-critical-care units, with an intervention similar to one that was found to reduce multidrug-resistant organisms and bacteraemia in intensive care units.

Methods: The ABATE Infection (active bathing to eliminate infection) trial was a cluster-randomised trial of 53 hospitals comparing routine bathing to decolonisation with universal chlorhexidine and targeted nasal mupirocin in non-critical-care units. The trial was done in hospitals affiliated with HCA Healthcare and consisted of a 12-month baseline period from March 1, 2013, to Feb 28, 2014, a 2-month phase-in period from April 1, 2014, to May 31, 2014, and a 21-month intervention period from June 1, 2014, to Feb 29, 2016. Hospitals were randomised and their participating non-critical-care units assigned to either routine care or daily chlorhexidine bathing for all patients plus mupirocin for known methicillin-resistant Staphylococcus aureus (MRSA) carriers. The primary outcome was MRSA or vancomycin-resistant enterococcus clinical cultures attributed to participating units, measured in the unadjusted, intention-to-treat population as the HR for the intervention period versus the baseline period in the decolonisation group versus the HR in the routine care group. Proportional hazards models assessed differences in outcome reductions across groups, accounting for clustering within hospitals. This trial is registered with ClinicalTrials.gov, number NCT02063867.

Findings: There were 189 081 patients in the baseline period and 339 902 patients (156 889 patients in the routine care group and 183 013 patients in the decolonisation group) in the intervention period across 194 non-critical-care units in 53 hospitals. For the primary outcome of unit-attributable MRSA-positive or VRE-positive clinical cultures (figure 2), the HR for the intervention period versus the baseline period was 0·79 (0·73-0·87) in the decolonisation group versus 0·87 (95% CI 0·79-0·95) in the routine care group. No difference was seen in the relative HRs (p=0·17). There were 25 (<1%) adverse events, all involving chlorhexidine, among 183 013 patients in units assigned to chlorhexidine, and none were reported for mupirocin.

Interpretation: Decolonisation with universal chlorhexidine bathing and targeted mupirocin for MRSA carriers did not significantly reduce multidrug-resistant organisms in non-critical-care patients.

Funding: National Institutes of Health.

Figure 1.. ABATE Infection Trial CONSORT Diagram

CONSORT diagram showing the recruitment and randomization process for the ABATE Infection Trial. N indicates the number of patients in the intervention period in each arm with their associated unit-attributable days, defined as patient days occurring from 3 days in the participating unit through two days after unit discharge if still hospitalized.

Figure 2.. Outcomes in Total Trial Population

Graphic showing impact of trial interventions on trial outcomes in the overall trial population. Arm-specific hazard ratios and confidence intervals from proportional hazards models (intent-to-treat unadjusted) accounting for clustering by hospitals are shown for MRSA or VRE clinical cultures (2A), MDR-GNR clinical cultures (2B), and all-pathogen bloodstream infection (2C). Bubble plots of hazard ratios (predicted random effects or exponentiated frailties) from individual hospitals relative to their arm effects are shown adjacent to arm-specific hazard ratios and confidence intervals. The size of the bubble is proportional to the number of patients contributing data to the trial. NOTE: Change in figure due to addition of middle panel. Hard to track changes.

Figure 3.. Outcomes in Patients with Devices

Graphic showing impact of trial interventions on trial outcomes in the post-hoc subpopulation of patients with devices. Arm-specific hazard ratios and confidence intervals from proportional hazards models (intent-to-treat, unadjusted) accounting for clustering by hospitals are shown for MRSA or VRE clinical cultures (3A), all-pathogen bloodstream infection (3B), MRSA clinical cultures only (3C), and VRE clinical cultures only (3D). Results remained significant after adjusting for multiple comparisons. Bubble plots of hazard ratios (predicted random effects or exponentiated frailties) from individual hospitals relative to their arm effects are shown adjacent to arm-specific hazard ratios and confidence intervals. The size of the bubble reflects the relative number of patients contributing data to the subpopulation. NOTE: Change in figure due to extending p-values out to 4 digits. Hard to track changes.