How Often Does Treatment Follow the Guidelines?

This article presents data from the report as well as findings from industry research exploring practitioner’s current attitudes toward antimicrobial resistance (AMR). Future articles will explore the implications of AMR for veterinary practitioners and discuss strategies for improving guideline concordance in daily practice.

VET Report Vitals focuses on the results of the groundbreaking Banfield Veterinary Emerging Topics (VET) Report™ “Are We Doing Our Part to Prevent Superbugs? Antimicrobial Usage Patterns Among Companion Animal Veterinarians.” This report, a collaboration between the NAVC and Banfield Pet Hospital, aims to promote prudent antimicrobial use among companion animal practitioners by providing a baseline of antimicrobial usage data that can contribute to the discussion on how to achieve better concordance with published guidelines.

Practitioners’ Attitudes Toward Antimicrobial Resistance

Antimicrobials are a cornerstone of treatment for many conditions, and their use can be critical for patient quality of life and survival. As such, antimicrobial resistance (AMR) not only affects the provision of safe and effective care, but also represents a critical and growing threat to public health. Evidence suggests that AMR is an important concern for many companion animal practitioners, with 59% of respondents to a survey of clinical veterinarians at a veterinary teaching hospital¹ and 45% of respondents to an American Veterinary Medical Association (AVMA) survey of self-identified companion animal practitioners² indicating they were strongly concerned about antimicrobial-resistant infections.

Despite these concerns, awareness of available resources, such as guidelines for judicious use and disease-specific treatment recommendations, remains low. Most respondents to the AVMA survey indicated that they would like additional guidance regarding the choice of antimicrobials for various infections (77%) and the duration of antimicrobial treatment (83%), yet 88% were unaware of the existence of antimicrobial usage guidelines created by veterinary professional associations (Figure 1). Given this low level of awareness, poor concordance of usage patterns with guideline recommendations might be expected.

Concordance of Current Usage Patterns With Guideline Recommendations

The availability of population-based data on antimicrobial use in companion animals from the electronic medical records of Banfield Pet Hospital provides an excellent snapshot of current usage patterns in general practice. This year’s edition of the VET Report™ explored antimicrobial usage patterns among companion animal practitioners to help inform voluntary adjustments that could result in a better balance between patient care and public health.

Methodology

The report looked at antimicrobial usage patterns from the electronic medical records of dogs evaluated for urinary tract infections (UTIs) or respiratory tract infections (RTIs) at any of 926 general-practice Banfield Pet Hospitals over the course of a calendar year (January 1, 2015–December 31, 2015). Usage patterns were evaluated for concordance with recommendations for antimicrobial treatment (drug, dosage, frequency, and duration) of UTIs and RTIs published by the Antimicrobial Guidelines Working Group of the International Society for Companion Animal Infectious Diseases (ISCAID).^3,5 Because the primary aim was to evaluate concordance with current first-line treatment guidelines, only episodes in which a single antimicrobial was dispensed were included in the analysis.

Antimicrobial Use in Urinary Tract Infections

There were 24,801 episodes of canine UTI treated with a single antimicrobial at Banfield Pet Hospitals in 2015 (Table 1). Episodes were further classified as recurrent or nonrecurrent based on whether the patient had experienced 2 or more UTIs in the preceding 12 months. Of the 24,801 episodes evaluated, 95% were determined to be nonrecurrent in nature, whereas 5% were preceded by 2 or more UTIs in the previous year.

The most recently published guidelines for care of nonrecurrent UTIs recommend initial treatment with amoxicillin (11–15 mg/kg PO q8h) or trimethoprim–sulfonamide (15 mg/kg PO q12h) for a duration of 7 days.³ Amoxicillin–clavulanate (12.5–25 mg/kg PO q8h) is described as an acceptable option, but not recommended owing to lack of evidence of the need for clavulanic acid. Based on these criteria, 9% of nonrecurrent UTI episodes received a guideline-concordant antimicrobial, although that number increases to 67% if amoxicillin–clavulanate is considered an acceptable option.

For recurrent UTIs, guidelines recommend that providers consider waiting for culture and susceptibility (C&S) results before instituting therapy. In cases where immediate treatment is warranted, the same recommendations as for nonrecurrent UTIs apply, with the additional recommendations that antimicrobial therapy be given for a duration of 4 weeks and that an alternative drug class to the one used for treatment of the previous UTI be dispensed. For recurrent infections, 7% of episodes received a guideline-concordant drug, increasing to 44% if amoxicillin–clavulanate is considered concordant.

Information about dosage, frequency, and duration was unavailable as structured data, so a utilization snapshot was obtained by conducting a manual review of the medical notes from a random sample of 500 UTI episodes: 250 for which amoxicillin was dispensed and 250 for which amoxicillin–clavulanate was dispensed. For amoxicillin, 34% of the reviewed prescriptions were concordant with the ISCAID recommended dosage and 14% were concordant with both the recommended frequency and duration. For amoxicillin–clavulanate, 78% of reviewed prescriptions were concordant with the recommended dosage, <1% with the recommended frequency, and 28% with the recommended duration.

Antimicrobial Use in Respiratory Tract Infections

There were 24,402 episodes of guideline-related canine respiratory disease treated with a single antimicrobial at Banfield Pet Hospitals in 2015, 95% of which were classified as canine infectious respiratory disease complex (CIRD) and 5% as bacterial bronchitis (Table 2).

Fifteen of 17 reviewers in ISCAID’s recently published guidelines for treatment of RTI recommended first-line treatment of the bacterial component of CIRD with doxycycline (5 mg/kg PO q12h or 10 mg/kg PO q24h) for a duration of 7 to 10 days.⁵ Amoxicillin–clavulanate (11 mg/kg PO q12h) was considered a suitable alternative by 13 of 17 reviewers. For bacterial bronchitis, doxycycline (5 mg/kg PO q12h or 10 mg/kg PO q24h) was recommended by 16 of 17 reviewers as the preferred empirical choice while waiting for results of C&S testing. Based on these criteria, 25% of CIRD episodes were treated with a guideline-concordant antimicrobial—increasing to 80% if amoxicillin–clavulanate is considered a suitable alternative—while 22% of bronchitis episodes received a guideline-concordant drug.

The medical notes from a random sample of 500 RTI episodes were reviewed to obtain information on the dosage, frequency, and duration of antimicrobial use: 250 for which doxycycline was dispensed and 250 for which amoxicillin–clavulanate was dispensed. For doxycycline, 29% of reviewed prescriptions were concordant with the ISCAID recommended dosages, 100% with the recommended frequency, and 46% with the recommended duration. For amoxicillin–clavulanate, 6% of reviewed prescriptions were concordant with the ISCAID recommended dosage, 100% with the recommended frequency, and 51% with the recommended duration.

Clinical Bottom Line

Antimicrobial usage data from 926 general-practice hospitals throughout the United States indicate that there is room for improved concordance with existing guidelines. Evidence suggests that low concordance may be driven by a lack of awareness of available resources. As such, strategies are needed to make the transition from publication of guidelines to incorporation of guidelines into practice. Upcoming VET Report Vitals articles will explore the implications of AMR for veterinary practitioners and discuss strategies for improving guideline concordance in daily practice.