Skip to main content Accessibility help


  • Access


      • Send article to Kindle

        To send this article to your Kindle, first ensure is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

        Note you can select to send to either the or variations. ‘’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

        Find out more about the Kindle Personal Document Service.

        Implementation of a carbapenem prescribing algorithm at a community hospital
        Available formats

        Send article to Dropbox

        To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

        Implementation of a carbapenem prescribing algorithm at a community hospital
        Available formats

        Send article to Google Drive

        To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

        Implementation of a carbapenem prescribing algorithm at a community hospital
        Available formats
Export citation


Cite this article: Shimata SE, et al. (2018). Implementation of a carbapenem prescribing algorithm at a community hospital. Infection Control & Hospital Epidemiology 2018, 39, 1503–1504. doi: 10.1017/ice.2018.256

To the Editor—Sutter Tracy Community Hospital (STCH) is a nonprofit 79-bed acute-care hospital located in Northern California serving more than 100,000 people in the Central Valley region. In 2015, the STCH Antimicrobial Stewardship Program (ASP) established a multidisciplinary committee under the leadership of a consultant ASP physician and an ASP certified pharmacist to coordinate antibiotic stewardship efforts and to support the implementation of new initiatives.

Carbapenems have broad-spectrum activity against gram-positive and gram-negative bacteria, including organisms producing extended spectrum β-lactamases (ESBLs). Unrestricted use and overuse of these agents leads to limited susceptibility profiles and reduced treatment options. Carbapenem-resistant Enterobacteriaceae (CRE) bacteria have been on the rise and have been deemed an urgent threat level by the Centers for Disease Control and Prevention (CDC). More than 9,000 healthcare-associated infections are caused by CRE bacteria each year, with a reported 40–50% mortality rate for invasive infections. 1 , 2 An additional serious threat is multidrug-resistant Pseudomonas aeruginosa, which accounts for 13% of all hospital-acquired P. aeruginosa infections. These organisms often exhibit high rates of cross resistance with all β-lactam antibiotics. 1 , 3

Promoting the appropriate use of antibiotics by decreasing inappropriate prescribing is a key element of antibiotic stewardship to reduce the emergence of resistance. 4 Studies have shown that unrestricted use of carbapenems have been linked to high rates of inappropriate use, thereby offering opportunities for the selection of narrower-spectrum agents or therapy de-escalation. Pharmacy-driven stewardship efforts have been successful with carbapenem de-escalation, but data demonstrating the direct effect of antibiotic stewardship interventions on improving their susceptibility profiles are lacking. 5 8

The STCH Antimicrobial Stewardship Committee noted imipenem-cilastatin as the antipseudomonal β-lactam with the lowest susceptibility to P. aeruginosa (88%) and a concerning decreasing trend from previous years (92% in 2013). A Carbapenem Prescribing Algorithm (Fig. 1) was developed as guidance to prescribers to promote the appropriate use of carbapenems. Pharmacists utilized prospective audit and feedback for new orders that failed to meet the algorithm’s use criteria and recommended alternative therapy. The objective of this stewardship initiative was to decrease overall carbapenem use by improving prescribing habits and promoting the appropriate use of these antibiotics. Buy-in was obtained from hospital physicians at the Department of Medicine committee meeting prior to implementation.

Fig. 1 Carbapenem Prescribing Algorithm


A quasi-experimental study was conducted utilizing a retrospective medication use evaluation (MUE). Three months of pre-intervention baseline data were collected from January to March 2015. The Carbapenem Prescribing Algorithm was implemented in December 2016 with education completed with prescribers and clinical pharmacists. In addition, 3 post-intervention follow-up periods of data were collected: immediate post-intervention (January–March 2016), 6 months post-intervention (July–September 2016), and 1 year post-intervention (January–March 2017). The primary endpoints were carbapenem days of therapy adjusted per 1,000 patient days (DOT) and percent of patients who met algorithm use criteria. Secondary endpoints included antibiogram susceptibility and cost savings using pharmacy purchasing data.


A 3-fold decrease in DOT was observed from baseline (131.8) to immediately post-intervention (40.2) and remained low (42.9) 6 months post-intervention. Although DOT increased to 64.5 by 1 year post-intervention, it remained ~50% lower than the baseline level. At baseline, only 20% of patients met algorithm use criteria, which increased to 35% immediately post-intervention. At 6 months and 1 year post-intervention, the percentage of patients who met algorithm use criteria increased to 70% and 79% respectively, nearly 3- to 4-fold compared to the baseline. The overall reduction in carbapenem use improved susceptibility to P. aeruginosa. After implementation of the Carbapenem Prescribing Algorithm, the hospital antibiogram susceptibility increased to 89% in 2015 and to 92% in 2016, a return to the 2013 percentage. Additionally, using 2015 as baseline, a $75,000 pharmacy cost savings was calculated for 2016 and $65,000 cost savings for 2017, which was attributed to the direct impact of implementing the Carbapenem Prescribing Algorithm.


The implementation of a pharmacy-driven Carbapenem Prescribing Algorithm at a small community hospital improved prescribing habits and the appropriate use of these agents. This intervention also led to a 3-fold reduction in overall carbapenem use, improvement of local antibiogram susceptibilities, and cost savings for the hospital. Success with the algorithm continued 6 months and 1 year post-intervention. Although carbapenem utilization increased 1 year post-intervention, 79% of this use was deemed appropriate based on algorithm criteria.

This study had some limitations. It was conducted at a small community hospital, so our results may not be generalizable to larger academic and trauma centers with varying rates of carbapenem resistance and susceptibility trends. Additionally, cost savings was calculated from antibiotic purchasing data, so these results may underestimate true cost savings. During our study period, there were several antibiotic drug shortages, so a larger supply of alternative antibiotics, such as carbapenems, may have been purchased in anticipation of a prolonged shortage.

Strengths of this study include assessment of outcomes for an extended duration, up to 1 year post-intervention, to evaluate the long- term effect of the implementation of the algorithm, which allowed study investigators to identify continued effects of the intervention. Due to a smaller physician and pharmacy personnel pool who were also amenable to the implementation of the algorithm, pharmacists were able to provide effective education on appropriate carbapenem prescribing that was sustained over time. This may also be a reason that these protocols are more successful in smaller institutions if buy-in is obtained before the protocol is implemented.

Pharmacy-driven ASP strategies may be particularly effective at both reducing antimicrobial utilization and improving antimicrobial susceptibility trends at small community hospitals.


We would like to acknowledge the STCH Antimicrobial Stewardship Committee and the Pharmacy Department for implementing the Carbapenem Prescribing Algorithm and the hospital physicians for supporting the success of our ASP.

Financial support

None reported.

Conflicts of interest

All authors report no conflicts of interest to this article.


1. US Department of Health and Human Services. Antimicrobial resistance threats in the United States, 2013. Centers for Disease Control and Prevention website. Published 2013. Accessed June 12, 2018.
2. Livorsi, DJ, Chorazy, ML, Schweizer, ML, et al. A systematic review of the epidemiology of carbapenem-resistant Enterobacteriaceae in the United States. Antimicrob Resist Infect Control 2018;55:19.
3. Sader, HS, Huband, MD, Castanheira, M, et al. Pseudomonas aeruginosa antimicrobial susceptibility results from four years (2012 to 2015) of the International Network for Optimal Resistance Monitoring Program in the United States. Antimicrob Agents Chemother 2017;61:17.
4. Barlam, TF, Cosgrove, SE, Abbo, LM, et al. Implementing an antibiotic stewardship program: guidelines by the Infectious Diseases Society of America and the Society for Healthcare Epidemiology of America. Clin Infect Dis 2016;62:e51e77.
5. Lai, C, Shi, Z, Chen, Y, et al. Effects of various antimicrobial stewardship programs on antimicrobial usage and resistance among common gram-negative bacilli causing health-care associated infections: a multicenter comparison. J Microbiol Immunol Infect 2016;49:7482.
6. Lew, KY, Ng, TM, Tan, M, et al. Safety and clinical outcomes of carbapenem de-escalation as part of an antimicrobial stewardship programme in an ESBL-endemic setting. J Antimicrob Chemother 2015;70:12191225.
7. Ahmad, F, Pogue, JM, Marchaim, D, et al. Evaluation of the potential impact of a carbapenem de-escalation program in an academic healthcare system. J Infect Public Health 2014;7:5053.
8. Janssen, J, Kinkade, A, Man, D. Carbapenem utilization evaluation in a large community hospital (CARBON): a quality improvement study. Can J Hosp Pharm 2015;68:327331.