4. 137 Hospital Cluster-Randomized Trial of Mupirocin-Chlorhexidine vs Iodophor-Chlorhexidine for Universal Decolonization in Intensive Care Units (ICUs) (Mupirocin Iodophor Swap Out Trial)

Abstract

Background. ICU universal decolonization with daily chlorhexidine (CHG) baths plus mupirocin nasal decolonization reduces all‐cause bloodstream infections (BSI) and MRSA clinical cultures. We assessed nasal iodophor, an antiseptic less susceptible to resistance, in place of mupirocin. Methods. We conducted a cluster randomized non‐inferiority trial in ICUs, comparing universal decolonization with: 1) Mupirocin‐CHG: daily CHG baths and 5 days of twice daily nasal mupirocin, to 2) Iodophor‐CHG: same regimen, substituting twice daily 10% povidone‐iodine for mupirocin. All adult ICUs in a hospital were assigned to the same strategy. We compared each hospital's outcomes during the 18‐month intervention (Nov 2017‐Apr 2019) to its own baseline (May 2015‐Apr 2017), during which all hospitals used mupirocin‐CHG. The primary outcome was ICUattributable S. aureus clinical isolates. Secondary outcomes included ICU‐attributable MRSA clinical isolates and all‐cause BSI. As randomized and as treated analyses used unadjusted proportional hazards models assessing differences in outcomes between baseline and intervention periods across the two groups, accounting for clustering by hospital and patient. Results. We randomized 137 hospitals with 233 ICUs in 18 states. There were 442,544 admissions in the baseline period and 349,262 in the intervention period. Median ICU length of stay was 4 days. ICU types included mixed medical surgical (56%), medical (9%), surgical (11%), cardiac (15%), and neurologic (9%). CHG adherence was similar in both arms (85%), but adherence was greater for mupirocin (90%) than iodophor (82%). Primary as‐randomized results (Table, Figure) exceeded the non‐inferiority margin in favor of mupirocin, for S. aureus clinical cultures (21% superiority, P< 0.001) and for MRSA clinical cultures (20% superiority, P< 0.001). The regimens had similar BSI hazards. Analyses of fully adherent patients are in progress. Conclusion. Universal iodophor‐CHG was equivalent to mupirocin‐CHG for ICU BSI prevention. Mupirocin‐CHG was superior to iodophor‐CHG for S. aureus and MRSA clinical isolates, potentially due to greater adherence to mupirocin.