What is the purpose of the culture and sensitivity when prescribing antibiotics?

Action

Antibiotic stewardship interventions improve patient outcomes (7, 9). An initial assessment of antibiotic prescribing can help identify potential targets for interventions.

Priority Interventions to Improve Antibiotic Use

Stewardship programs should choose interventions that will best address gaps in antibiotic prescribing and consider prioritizing prospective audit and feedback, preauthorization and facility-specific treatment guidelines.

Published evidence demonstrates that prospective audit and feedback (sometimes called post-prescription review) and preauthorization are the two most effective antibiotic stewardship interventions in hospitals (16). They are both strongly recommended in evidenced-based guidelines and can be considered “foundational” interventions for hospital stewardship programs.

Prospective audit and feedback is an external review of antibiotic therapy by an expert in antibiotic use, accompanied by suggestions to optimize use, at some point after the agent has been prescribed (16). Prospective audit and feedback is different from an antibiotic “timeout” because the stewardship program rather than the treating team conducts the audits.

Audit and feedback can be implemented in a variety of ways, depending on the level of expertise available. Stewardship programs with limited infectious diseases expertise might choose to focus reviews on comparing prescribed treatment courses to recommendations in hospital specific treatment guidelines and focus on common conditions, such as community-acquired pneumonia, urinary tract infection, or skin and soft tissue infection. Programs with more advanced infectious diseases expertise might elect to review more complex antibiotic treatment courses.

The effectiveness of prospective audit with feedback can be enhanced by providing feedback in face-to-face meetings with providers, referred to as “handshake stewardship” (32) (41).

Preauthorization requires prescribers to gain approval prior to the use of certain antibiotics. This can help optimize initial empiric therapy because it allows for expert input on antibiotic selection and dosing, which can be lifesaving in serious infections, like sepsis. It can also prevent unnecessary initiation of antibiotics (42).

Decisions on which antibiotics to place under preauthorization should be made in consultation with providers to focus on opportunities to improve empiric use, rather than on drug costs (43). This intervention requires the availability of expertise and staff who can complete authorizations in a timely manner (44). Hospitals can tailor the agents, situations, and mechanisms (e.g. preauthorization through an electronic order entry system) to implement preauthorization based on program goals, available expertise, and resources in a way that does not delay therapy for serious infections. Stewardship programs should monitor potential unintended consequences of preauthorization, especially treatment delays.

Two studies have compared these two interventions directly and found prospective audit and feedback to be more effective than preauthorization (42, 44). However, many experts suggest that these interventions should both be priorities for implementation since preauthorization can help optimize initiation of antibiotics and prospective audit and feedback can help optimize continued therapy. Hospitals can use local data and knowledge of practices to determine which antibiotics should be subject to prospective audit and feedback and/or preauthorization.

Facility specific treatment guidelines are also considered a priority because they can greatly enhance the effectiveness of both prospective audit and feedback and preauthorization by establishing clear recommendations for optimal antibiotic use at the hospital. These guidelines can optimize antibiotic selection and duration, particularly for common indications for antibiotic use like community-acquired pneumonia, urinary tract infection, intra-abdominal infection, skin and soft tissue infection and surgical prophylaxis. Recommendations may be based on national guidelines but should reflect hospital treatment preferences based on local susceptibilities, formulary options, and patient mix.

Ideally, the recommendations should also address diagnostic approaches, such as when to send diagnostic samples and what tests to perform, including indications for rapid diagnostics and non-microbiologic tests (e.g. imaging, procalcitonin). The development of treatment guidelines is a good way for the stewardship program to engage prescriber stakeholders to develop consensus on antibiotic use.

Hospital guidelines can also facilitate prospective audit with feedback and preauthorization as prescriptions and/or requests for antibiotics can be compared to hospital recommendations. Stewardship programs can prioritize the development of guidelines based on the infections most commonly encountered. Adherence to hospital guidelines can be enhanced by embedding treatment recommendations in order sets and clinical pathways.

Common Infection-based Interventions

More than half of all antibiotics given to treat active infections in hospitals are prescribed for three infections where there are important opportunities to improve use: lower respiratory tract infection (e.g. community acquired pneumonia), urinary tract infection and skin and soft tissue infection (45). Optimizing the duration of therapy can be especially important because many studies show infections are often treated for longer than guidelines recommend and data demonstrate that each additional day of antibiotics increases the risk of patient harm (4, 46). Examples of interventions are below and summarized in Table 1.

Community-acquired pneumonia: Interventions have focused on:

• Improving diagnostic accuracy
• Tailoring of therapy to culture results
• Optimizing the duration of treatment to ensure compliance with guidelines

The use of viral diagnostics and/or procalcitonin might help identify patients in whom antibiotics can be stopped because bacterial pneumonia is unlikely (47). Optimizing the duration of therapy at hospital discharge is especially important as most excess antibiotic use in the treatment of community-acquired pneumonia occurs after discharge (48, 49) .

Urinary tract infection (UTI): Many patients who are prescribed antibiotics for UTIs have asymptomatic bacteriuria that generally does not need to be treated. Successful stewardship interventions focus on avoiding obtaining unnecessary urine cultures and avoiding treatment of patients who are asymptomatic, unless there are specific reasons to treat (50). For patients who need treatment, interventions can focus on ensuring patients receive appropriate therapy based on local susceptibilities for the recommended duration (51).

Skin and soft tissue infection: Interventions have focused on ensuring patients with uncomplicated infections do not receive antibiotics with overly broad spectra (e.g. unnecessary coverage for methicillin-resistant Staphylococcus aureus (MRSA) and gram-negative pathogens) and prescribing the correct route, dosage and duration of treatment (52, 53).

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