193. Duration of Antimicrobial Therapy: The Impact of Defaults
Session: Poster Abstract Session: Antimicrobial Stewardship: Interventions Leveraging the Electronic Health Record
Thursday, October 4, 2018
Room: S Poster Hall
  • Wrenn Duration IDWeek 2018 .pdf (573.4 kB)
  • Background: Default durations imbedded in the electronic prescription (e-script) order entry process may be interpreted by providers as duration recommendations. This process could lead to inappropriately long durations of therapy for antibiotics, especially at hospital discharge when patients have received inpatient antibiotics.  

    Methods:   Default durations of 7 or 10 days for fluoroquinolones (FQ) were removed from inpatient and outpatient e-scripts from Duke University Health System (DUHS) hospitals (1 academic, 2 community) and clinics (N=86) on 12/19/17.  We evaluated the impact on FQ duration by comparing mean duration and percent of 10 day durations in the 12 months pre-default duration removal (DDR) and 3 months post-DDR.   All inpatient or outpatient encounters with a FQ e-script with days duration less than 31 days were included. FQ durations were captured in days duration fields or calculated from sig and quantity fields.  We used descriptive statistics to compare FQ duration pre- and post-DDR using a chi-squared test. 

    Results: A total of 35,765 FQ e-scripts and 276,056 FQ e-script days of therapy were included pre-DDR.  The post-DDR included 9,526 FQ e-scripts and 71,028 FQ e-script days of therapy. Mean (standard deviation) durations in the pre and post periods were 7.78 (4.35) and 7.55 (3.99), respectively (p<0.001). Common discharge durations in both time periods across all settings were 5, 7, and 10 days. The 10-day default duration was the most common in the pre-DDR with 11,000 e-scripts (31%), and declined by 16% (2475 e-scripts, 26%) in the post-DDR period.  The academic center realized the greatest shift away from 10-day default duration (Table 1).

    Conclusion: Removal of default e-script durations, a novel and minimally resource intensive strategy, reduced prescribed duration of FQ therapy.   

    Table 1. Ten-day Durations for Fluoroquinolone E-scripts Pre- and Post-DDR

    Practice Setting


    N (%) 10 day E-scripts


    N (%) 10 day E-scripts

    % Change Pre-Post

    Academic Medical Center

    771 (20)

    125 (11)


    Community hospital

    452 (20)

    90 (15)


    Community hospital

    514 (24)

    126 (21)



    9263 (34)

    2134 (30)



    11000 (31)

    2475 (26)



    Rebekah Wrenn, PharmD1,2, Tony Diez, Sr., MBA, RRT3, Nicholas Turner, MD4, Christina Sarubbi, PharmD1, Deverick J. Anderson, MD, MPH, FIDSA, FSHEA5 and Rebekah W. Moehring, MD, MPH4, (1)Duke Center for Antimicrobial Stewardship and Infection Prevention, Durham, NC, (2)Pharmacy, Duke University Hospital, Durham, NC, (3)Duke University Medical Center, Durham, NC, (4)Division of Infectious Diseases, Duke University Medical Center, Durham, NC, (5)Duke Infection Control Outreach Network, Duke University Medical Center, Durham, NC


    R. Wrenn, None

    T. Diez, Sr., None

    N. Turner, None

    C. Sarubbi, None

    D. J. Anderson, None

    R. W. Moehring, None

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