Study of 2% Chlorhexidine Gluconate-Impregnated Bath Cloths to Prevent MRSA Colonization in Complex Continuing Care

• Incidence of MRSA colonization [ Time Frame: 12 months ] [ Designated as safety issue: No ]
  Primary outcome measure will be incidence of MRSA colonization measured through bi-weekly point-prevalence surveys on each of the three units. All new admissions and re-admissions to the units will also be screened. Protective properties of CHG bathing are expected to significantly reduce the incidence of MRSA transmission in the intervention arm, compared to control arms.
  
  

• Time to MRSA conversion [ Time Frame: 12 months ] [ Designated as safety issue: No ]
  Secondary outcome measure will be time to MRSA conversion measured as the length of time it takes patients to convert from being MRSA-negative at enrollment to MRSA-positive at discharge or end of the study. Protective properties of CHG bathing are expected to significantly prolong conversion time.
  
  

Bathing patients with 2% chlorhexidine gluconate-impregnated cloths (CHG) is an established practice at Baycrest. Our previous studies have demonstrated strong MRSA-preventive properties of CHG bathing practice - the rate of MRSA transmission on intervention units dropped from 4.99 to 0.88 cases per 1,000 patient days - an overall rate reduction of 82%.

Although CHG will continue to be used as part of an established clinical practice in our hospital, its impact on MRSA prevention merits further evaluation in complex continuing care (CCC) settings endemic for MRSA. Investigators propose a cluster-randomized, prospective, open-label, two-arm clinical trial (RCT) on three geographically separate, but otherwise comparable, CCC units - one intervention unit using CHG, and two control units using non-antiseptic cleanser. The RCT is expected to conclusively answer whether daily bathing with CHG significantly reduces incidence of MRSA colonization.

By cluster randomization investigators imply randomly assigning interventions to the three patient care units. Investigators propose randomization of the units as it is not feasible to randomly assign the individual participants to intervention vs control arms.

For a meaningful interpretation of the RCT findings, patient populations on the three floors will be compared at the beginning, during, and at the end of the study. The following variables will be used to compare patient populations:

• Colonization pressure (CP) is a measure of the MRSA reservoir on the unit. CP will be calculated at the onset of the RCT and then bi-weekly (Number of MRSA patient-days × 100 ÷ Total Number of Patient Days).
• Average Braden scale score (BSS) for patients on each unit is measured to predict a pressure ulcer risk. It is one of the measures of patient's clinical complexity. It is calculated by examining six patient criteria (sensory perception, skin moisture, physical activity, mobility, nutrition, friction and shear). BSS will be calculated at the onset of the RCT and then monthly.
• Average Case Mix Index (CMI) is a value reflecting the daily relative weight of resources used by an individual patient compared to a base resource level (the average resource use of the patient population). The CMI value is not a dollar amount; rather it is a relative value and an indirect marker of patient's clinical complexity. CMI will be calculated at the onset of the RCT and then quarterly.

Patient information will be de-identified for privacy reasons, before analysis of the study data - logistic regression, to compare the rates of MRSA incidence and time to MRSA conversion on intervention and control units.