Clinical Trial: Rapid Identification and Susceptibility Testing of Pathogens From Blood Cultures

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Rapid Identification and Susceptibility Testing of Pathogens Growing in Blood Culture Bottles - A Quality Improvement Theragnostic Stewardship Project

Brief Summary: Would rapid identification of bacteria and rapid detection of methicillin-resistant S. aureus (MRSA) and vancomycin-resistant enterococci (VRE) (using an FDA-cleared assay) in positive blood culture bottles improve patient care at Mayo Clinic Rochester (or just lead to increased cost)?

Detailed Summary: We hypothesize that the FilmArray Blood Culture ID Panel will reduce the duration of empiric broad-spectrum antimicrobial therapy typically administered in patients who have positive blood cultures, improving clinical outcome and reducing cost. To test this hypothesis we propose a prospective, randomized controlled study comparing outcomes among patients with positive blood cultures who receive either: Standard culture and antimicrobial susceptibility testing (AST) of positive blood culture bottles as is done today (control), standard culture and AST of positive blood culture bottles plus the FilmArray Blood Culture ID Panel (intervention group 1), or standard culture and AST of positive blood culture bottles plus the FilmArray Blood Culture ID Panel testing along with expert infectious diseases phone consultation (intervention group 2). In both intervention groups, results of the FilmArray test will be communicated by phone to the primary service, along with templated comments about optimal antimicrobial therapy, based on the result. (Templated comments will also be used in the control group). In intervention group 2, an infectious diseases pharmacist or physician will provide patient-specific recommendations to modify antimicrobial therapy, if appropriate, based on microbiology results and clinical information obtained through medical record review and discussion with the primary service.
Sponsor: Mayo Clinic

Current Primary Outcome: Duration of Antimicrobial Therapy (Hours) [ Time Frame: Approximately 4 days after enrollment ]

Original Primary Outcome: Vancomycin and anti-pseudomonal antibiotic days of therapy per patient [ Time Frame: within 14 days following gram-stain positive blood culture ]

Current Secondary Outcome:

• Time From Positive Gram Stain to First Active Antibiotic [ Time Frame: Approximately 14 days after positive blood culture ]
  From positive Gram stain to start of active antibiotic among patients not on active therapy at enrollment; excludes subjects with contaminated blood cultures.
• Time to First Appropriate De-escalation or First Appropriate Escalation of Antibiotics [ Time Frame: Positive Gram stain, 96 hours after enrollment ]
  De-escalation included discontinuation of 1 or more antibiotics and/or switching from a broad- to a narrow spectrum antibiotic. Escalation included initiation of 1 or more antibiotics and/or switching from a narrow- to a broad-spectrum antibiotic.
• Percent of Contaminated Blood Cultures Not Treated or Treated for Less Than 24 Hours [ Time Frame: Within 14 days after positive blood culture ]
  Contaminated blood cultures were defined as growth of organisms such as coagulase-negative staphylococci from a single blood culture set when greater than or equal to 2 blood culture sets were collected, except among subjects suspected to have true bacteremia associated with central venous catheters or devices.
• Time to Pathogen Identification [ Time Frame: Approximately 14 days after positive blood culture ]
• Number of Subjects Who Had Negative Blood Cultures Within 3 Days After Enrollment [ Time Frame: 3 Days after enrollment ]
• Length of Entire Hospitalization (Days) [ Time Frame: Participants were followed for the duration of hospital stay, approximately 15 days ]
• All-cause and Attributable Mortality [ Time Frame: 30 days after positive blood culture ]
  If records of death were incomplete, mortality was determined using Accurint (LexisNexis, Philadelphia, PA), an internet research and location service.
• Number of Subjects With Antibiotic-Associated Toxicities/Adverse Events [ Time Frame: Approximately 14 days after positive blood culture ]
  This included all adverse events that occurred within 2 weeks following enrollment and were documented in the medical record.
• Percentage of Subjects With Infectious Disease Consultation Within 72 Hours of Enrollment [ Time Frame: Approximately within 72 hours of positive blood culture ]
• Mean Total Hospitalization, Laboratory Test, and Antimicrobials Costs Per Subject [ Time Frame: Approximately 7 days after positive blood culture and for duration of entire hospitalization ]
  Costs were calculated using a standardized inflation-adjusted estimate of costs for each service or procedure performed in constant dollars. This approach adjusts for hospital-billed charges with Medicare Cost Report department-level cost-to-charge ratios. Physician services were proxied with Medicare reimbursement rates based on Current Procedure Terminology (CPT)-4 codes using the Medicare Fee Schedule. We did not include the cost of the stewardship program in the cost analysis, as it is not a billed service. As there was no Medicare reimbursement rate for the rmPCR test at the time of the study, test cost was proxied using the FilmArray respiratory panel. These costs were varied in sensitivity analysis with rmPCR test cost ranging from a 50% decrease to a 300% increase.

Original Secondary Outcome: Time to appropriate antibiotic deescalation or escalation (# days after gram-stain positive blood culture) [ Time Frame: within 14 days after gram-stain positive blood culture ]

Information By: Mayo Clinic

Dates:
Date Received: July 8, 2013
Date Started: August 2013
Date Completion:
Last Updated: February 17, 2016
Last Verified: February 2016