There is a paucity of data describing the minimum acceptable susceptibility (MAS) of empirical antimicrobial regimens based on severity of illness, prognosis, and practitioner level of comfort.
The purpose of this study was to determine the MAS used by pharmacists involved in antimicrobial decision making for gram-negative bloodstream infections.
This cross-sectional survey targeted infectious diseases and/or critical care pharmacists. The 11-item survey was distributed electronically in September and October 2014. Survey respondents were asked to indicate a 2-digit number (between 59% and 99%) representing their MAS targets for each clinical scenario (3 cases of gram-negative bloodstream infection of varying complexity and prognosis and 1 control scenario of uncomplicated cystitis). The median MAS were reported by prognosis as estimated by the Bloodstream Infection Mortality Risk Score (BSIMRS) and respondent characteristics.
Among 316 participant pharmacists, 209 (66%) and 52 (17%) identified infectious diseases and critical care as specialty practice areas, respectively. The median MAS was 90% for both case 1 (poor prognosis; BSIMRS: 13) and case 2 (guarded prognosis; BSIMRS: 8), 85% for case 3 (good prognosis; BSIMRS: 2), and 80% for case 4 (uncomplicated cystitis; BSIMRS: 0). There was a significant increase in median MAS as BSIMRS increased from 0 to 2 (P < 0.001) and from 2 to 8 (P < 0.001). The median MAS plateaued as BSIMRS increased from 8 to 13 (P = 0.20).
There was a proportional increase in respondents' median MAS as severity and complexity of infections progressed until MAS reached the maximum in patients with guarded/poor prognosis.
Patient-specific risk factors and population-based antibiograms based on local resistance patterns are frequently used to determine optimal empirical antibiotic therapy. A survey of infectious disease and critical care pharmacists involved in antibiogram development and in formulating empirical recommendations demonstrated that median minimum acceptable susceptibilities (MAS) correspond to predicted prognosis among patients with Gram-negative bloodstream infections. Based on bloodstream infection mortality risk score, those with guarded or poor prognosis have a MAS of 90%.
From the *Department of Pharmacy, Palmetto Health Baptist, Columbia, SC;
†Department of Pharmacy, Mercy Hospital, Chicago, IL;
‡Department of Clinical Pharmacy and Outcomes Sciences, University of South Carolina College of Pharmacy;
§Department of Pharmacy, Palmetto Health Richland;
∥University of South Carolina School of Medicine; and
¶Department of Medicine, Palmetto Health–USC Medical Group, Columbia, SC.
Correspondence to: P. Brandon Bookstaver, PharmD, FCCP, FIDSA, BCPS, Associate Professor and Director of Residency and Fellowship Training, Department of Clinical Pharmacy and Outcomes Sciences, College of Pharmacy, University of South Carolina, Infectious Diseases Pharmacist, Palmetto Health Richland, 715 Sumter Street, Columbia, SC 29208. E-mail: firstname.lastname@example.org.
Disclosures: P.B.B. is a content development and honorarium recipient from Rockpointe Inc and FreeCe.com. M.N.A. is a content development and honorarium recipient from Rockpointe Inc. The other authors have no conflicts of interest to disclose.
Emily Haggard and Maureen Hagedorn were students at the South Carolina College of Pharmacy, University of South Carolina at the time of study.
These data were presented in part at the American Society of Health-System Pharmacists Midyear Clinical Meeting, December 7–11, 2014, Anaheim, Calif, Abstract #5-361.