Abstract
BackgroundAntibiotic overuse has contributed substantially to the rise of antibiotic resistance, in Australia and globally. In primary care, much of the antibiotic overuse occurs for acute infections such as acute respiratory infections (ARIs), some urinary tract infections (UTIs), and skin and soft tissue infections (SSTIs). These infections are often self-limiting, and antibiotics make little or no difference in reducing infection duration. Various factors contribute to antibiotic overuse including perceived and expressed patient expectations for antibiotics, diagnostic uncertainty, and the desire to preserve the patient-clinician relationship. Improving clinicians' and patients' knowledge of the natural history of common acute infections may help to manage patient expectations about recovery time and improve antibiotic stewardship. Existing research has not mapped the natural history evidence for common acute infections, how such evidence is communicated to clinicians, and whether it is used by primary care clinicians and patients when deciding about the management of acute self-limiting infections.
Aims
This thesis aimed to: 1) map existing research and research gaps relevant to the natural history of acute infections; 2) examine, in clinical practice guidelines, the reporting of natural history information and relevant antibiotic stewardship strategies for acute infections; 3) explore general practitioners’ (GPs) perceptions of the value and use of natural history information and guidelines resources to support antibiotic decision-making; and 4) explore the general public's expectation about the likely duration of acute infections and reasons for seeking care.
Methods
Four interrelated studies were conducted. Study 1 was a scoping review to map the natural history evidence of acute infections seen in primary care (ARIs, UTI, SSTIs) and identify research gaps. It used a two-phased search strategy to identify: i) systematic reviews which had synthesised natural history evidence and systematic reviews of placebo- or no-treatment controlled randomised trials which contained natural history information; and ii) trials for which no systematic reviews had been conducted. Study 2 was a systematic review of clinical guidelines used in primary care to examine the reporting of natural history information and the supporting evidence. Study 3 was a qualitative study in which semi-structured interviews with GPs were used to explore their perception of the value of natural history information and their awareness and use of guideline resources to support antibiotic prescribing decisions. Study 4 was a nationwide survey of adult Australians' expectations about the likely duration of acute infections and care-seeking behaviour.
Results
Study 1 identified 40 systematic reviews, which reported on a total of 45 infections, 15% of which focussed on synthesising natural history data. The evidence was most extensive and developed for ARIs (90% of reviews), with gaps in the evidence for SSTIs and UTIs. Most reviews reported the proportion of participants with symptom resolution at various time point/s, with 58% of reviews providing data on mean symptom duration. No studies examined the natural history of cellulitis, ecthyma, carbuncle, and erysipelas infections.
Study 2 identified 82 guidelines, covering 114 eligible infections, with 59.8% of the guidelines reporting natural history information, most commonly for ARIs. For 63.5% of the infections, the natural history information included quantitative data on the infection’s expected duration. Delayed antibiotic prescribing and shared decision making were recommended by the guidelines as strategies for 34% and 21% of the infections respectively.
Study 3 identified four themes: 1) GPs perceived natural history as valuable in consultations for self-limiting conditions and used it for a range of purposes, but desired specific information for various infectious and non-infectious conditions; 2) GPs' reason for using patient-facing resources were manifold, including managing patients' expectations for antibiotics, legitimising the decision to not provide antibiotic, and as a prescription substitute; 3) guidelines are a valuable and important educational resource but were typically not consulted at the time of deciding whether to prescribe antibiotics; and 4) GPs' experience and attitude towards shared decision making and looking up information during consultations influenced whether they involved patients in decision-making and used a decision aid.
In Study 4, the survey (n=589) found >60% of participants underestimated the mean duration of acute cough, sinusitis, conjunctivitis, and uncomplicated UTI compared with evidence-based duration estimates, whereas >70% of participants' mean estimates of the duration of common cold, sore throat, acute otitis media, and impetigo were within an evidence-based range. About two-thirds (62%) of participants indicated they were typically unlikely to seek care for self-limiting infections. The most common reasons for care-seeking were severe or worsening symptoms, a desire for quick recovery, and fear of progression to complications.
Conclusions and Implications
Findings from this thesis demonstrate that there is a body of evidence about the natural history of some of the acute infections that are commonly managed in primary care, especially ARIs, with much less evidence about UTIs and SSTIs. However, there is suboptimal incorporation of existing evidence into clinical practice guidelines, which is a missed opportunity to disseminate the available evidence to clinicians. Many GPs recognise the value in incorporating natural history information into consultations for acute infections, although ways of knowing this information and whether and how it was communicated with patients varied. Australian adults' knowledge of the typical duration of acute infections was diverse, with estimates more accurate for some conditions than others. Many Australian adults had few concerns about waiting for common infections to resolve spontaneously once they were aware of this.
Well-designed studies which generate robust evidence about the natural history of common infections are needed, particular for infections for which such research has been largely neglected to date. Exploring how to best incorporate natural history evidence and patient-focused antibiotic stewardship strategies, such as delayed prescribing and shared decision making, into clinician-facing resources like primary care clinical practice guidelines for acute infections and patient-facing resources, such as decision aids, is essential for facilitating evidence uptake in consultations and enhancing decision-making regarding antibiotic use. Ensuring consistent communication about the natural history of common infections across all primary care settings can help manage patients' expectations regarding recovery time, the necessity of seeking medical care and for antibiotics. To enhance the quality of care, it is crucial to improve the methodological standards of natural history research, fill existing knowledge gaps through additional studies particularly for infections that have been largely neglected and conduct systematic reviews focused on synthesising natural history data. The research conducted as part of this thesis has addressed previously unknown questions and generated findings that can improve antibiotic stewardship in primary care, thereby reducing the contribution of antibiotic overuse to antibiotic resistance.
Date of Award | 2025 |
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Original language | English |
Supervisor | Tammy Hoffmann (Supervisor) & Mina Bakhit (Supervisor) |