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Diagnostic stewardship of C. difficile testing: a quasi-experimental antimicrobial stewardship study

  • Alyssa B. Christensen (a1) (a2), Viktorija O. Barr (a2), David W. Martin (a1), Morgan M. Anderson (a1) (a3), Amanda K. Gibson (a1), Brian M. Hoff (a1), Sarah H. Sutton (a4) (a5), Valerie Widmaier (a6), Asra A. Salim (a5), Christina Silkaitis (a5), Chao Qi (a6) (a7), Teresa R. Zembower (a4) (a6) (a5), Michael J. Postelnick (a1) and Nathaniel J. Rhodes (a1) (a3) (a8)...



We evaluated whether a diagnostic stewardship initiative consisting of ASP preauthorization paired with education could reduce false-positive hospital-onset (HO) Clostridioides difficile infection (CDI).


Single center, quasi-experimental study.


Tertiary academic medical center in Chicago, Illinois.


Adult inpatients were included in the intervention if they were admitted between October 1, 2016, and April 30, 2018, and were eligible for C. difficile preauthorization review. Patients admitted to the stem cell transplant (SCT) unit were not included in the intervention and were therefore considered a contemporaneous noninterventional control group.


The intervention consisted of requiring prescriber attestation that diarrhea has met CDI clinical criteria, ASP preauthorization, and verbal clinician feedback. Data were compared 33 months before and 19 months after implementation. Facility-wide HO-CDI incidence rates (IR) per 10,000 patient days (PD) and standardized infection ratios (SIR) were extracted from hospital infection prevention reports.


During the entire 52 month period, the mean facility-wide HO-CDI-IR was 7.8 per 10,000 PD and the SIR was 0.9 overall. The mean ± SD HO-CDI-IR (8.5 ± 2.0 vs 6.5 ± 2.3; P < .001) and SIR (0.97 ± 0.23 vs 0.78 ± 0.26; P = .015) decreased from baseline during the intervention. Segmented regression models identified significant decreases in HO-CDI-IR (Pstep = .06; Ptrend = .008) and SIR (Pstep = .1; Ptrend = .017) trends concurrent with decreases in oral vancomycin (Pstep < .001; Ptrend < .001). HO-CDI-IR within a noninterventional control unit did not change (Pstep = .125; Ptrend = .115).


A multidisciplinary, multifaceted intervention leveraging clinician education and feedback reduced the HO-CDI-IR and the SIR in select populations. Institutions may consider interventions like ours to reduce false-positive C. difficile NAAT tests.


Corresponding author

Author for correspondence: Nathaniel J. Rhodes, Email:


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Present affiliation: Department of Pharmacy, Providence St. Vincent Medical Center, Portland, Oregon.


Present affiliation: Syneos Health/GlaxoSmithKline, Parsippany, New Jersey.


Present affiliation: Department of Pharmacy, Advocate Aurora Health, Chicago, Illinois.


Present affiliation: Department of Pharmacy, University of Utah Health, Salt Lake City, Utah.


Present affiliation: Division of Infection Prevention, VigiLanz, Chicago, Illinois.



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1.McDonald, LC, Gerding, DN, Johnson, S, et al. Clinical practice guidelines for Clostridium difficile infection in adults and children: 2017 update by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA). Clostridium Difficile 2018;66:987994.
2.Lessa, FC, Mu, Y, Bamberg, WM, et al. Burden of Clostridium difficile infection in the United States. N Engl J Med 2015;372:825834.
3.Healthcare-Associated Infections—Community Interface (HAIC). Annual report for the emerging infections program for Clostridium difficile infection, 2015. Centers for Disease Control and Prevention website. Published 2015. Accessed December 5, 2018.
4.Gerding, DN, Olson, MM, Peterson, LR, et al. Clostridium difficile-associated diarrhea and colitis in adults. A prospective case-controlled epidemiologic study. Arch Intern Med 1986;146:95100.
5.Samore, MH, DeGirolami, PC, Tlucko, A, Lichtenberg, DA, Melvin, ZA, Karchmer, AW. Clostridium difficile colonization and diarrhea at a tertiary care hospital. Clin Infect Dis 1994;18:181187.
6.Loo, VG, Bourgault, AM, Poirier, L, et al. Host and pathogen factors for Clostridium difficile infection and colonization. N Engl J Med 2011;365:16931703.
7.Lamendella, R, Wright, JR, Hackman, J, et al. Antibiotic treatments for Clostridium difficile infection are associated with distinct bacterial and fungal community structures. mSphere 2018;3:e00572–17.
8.Cannon, K, Byrne, B, Happe, J, et al. Enteric microbiome profiles during a randomized Phase 2 clinical trial of surotomycin versus vancomycin for the treatment of Clostridium difficile infection. J Antimicrob Chemother 2017;72:34533461.
9.Centers for Disease Control and Prevention. National Center for Emerging and Zoonotic Infectious Diseases. Division of Healthcare Quality Promotion. U.S. Deparment of Health and Human Services. National Healthcare Safety Network (NHSN). The NHSN standardized infection ratio (SIR): a guide to the SIR. Atlanta, GA: 2017. Available at:
10.Dubberke, ER, Han, Z, Bobo, L, et al. Impact of clinical symptoms on interpretation of diagnostic assays for Clostridium difficile infections. J Clin Microbiol 2011;49:28872893.
11.R Development Core Team. R: a language and environment for statistical computing. 3rd ed. Vienna, Austria: R Foundation for Statistical Computing. Published 2016. Accessed December 5, 2018.
12.Bernal, JL, Cummins, S, Gasparrini, A. Interrupted time series regression for the evaluation of public health interventions: a tutorial. Int J Epidemiol 2017;46:348355.
13.Kelly, SG, Yarrington, M, Zembower, TR, et al. Inappropriate Clostridium difficile testing and consequent overtreatment and inaccurate publicly reported metrics. Infect Control Hosp Epidemiol 2016;37:13951400.
14.Price, J, Cheek, E, Lippett, S, et al. Impact of an intervention to control Clostridium difficile infection on hospital- and community-onset disease; an interrupted time series analysis. Clin Microbiol Infect 2010;16:12971302.
15.Lewis, PO, Lundberg, TS, Tharp, JL, Runnels, CW. Implementation of global strategies to prevent hospital-onset Clostridium difficile. infection: targeting proton pump inhibitors and probiotics. Ann Pharmacother 2017;51:848854.
16.Barker, AK, Alagoz, O, Safdar, N. Interventions to reduce the incidence of hospital-onset Clostridium difficile infection: an agent-based modeling approach to evaluate clinical effectiveness in adult acute care hospitals. Clin Infect Dis 2018;66:11921203.
17.Kociolek, LK, Bovee, M, Carter, D, et al. Impact of a healthcare provider educational intervention on frequency of Clostridium difficile polymerase chain reaction testing in children: a segmented regression analysis. J Pediatric Infect Dis Soc 2017;6:142148.
18.Khoury, JA, Sistrunk, WW, Hixson, F, et al. Sustained reduction in rates of hospital-onset Clostridium difficile infection using an automated electronic health record protocol. Am J Infect Control 2018;46:542548.
19.Mermel, LA, Jefferson, J, Blanchard, K, et al. Reducing Clostridium difficile incidence, colectomies, and mortality in the hospital setting: a successful multidisciplinary approach. Jt Comm J Qual Patient Saf 2013;39:298305.
20.Quan, KA, Yim, J, Merrill, D, et al. Reductions in Clostridium difficile infection (CDI) rates using real-time automated clinical criteria verification to enforce appropriate testing. Infect Control Hosp Epidemiol 2018;39:625627.
21.White, DR, Hamilton, KW, Pegues, DA, Hanish, A, Umscheid, CA. The impact of a computerized clinical decision support tool on inappropriate Clostridium difficile testing. Infect Control Hosp Epidemiol 2017;38:12041208.
22.Christensen, AB, Gibson, AK, Martin, DW, Rhodes, NJ, et al. Reduction of inappropriate hospital-onset Clostridium difficile testing through preauthorization of PCR Clostridium difficile lab orders. ASM Microbe 2017. Platform presentation. New Orleans, LA.

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Diagnostic stewardship of C. difficile testing: a quasi-experimental antimicrobial stewardship study

  • Alyssa B. Christensen (a1) (a2), Viktorija O. Barr (a2), David W. Martin (a1), Morgan M. Anderson (a1) (a3), Amanda K. Gibson (a1), Brian M. Hoff (a1), Sarah H. Sutton (a4) (a5), Valerie Widmaier (a6), Asra A. Salim (a5), Christina Silkaitis (a5), Chao Qi (a6) (a7), Teresa R. Zembower (a4) (a6) (a5), Michael J. Postelnick (a1) and Nathaniel J. Rhodes (a1) (a3) (a8)...


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