Abstract
Background- Antibiotics are inappropriately prescribed for many acute respiratory infections (ARIs) in primary care, for which they offer marginal benefits. This use of antibiotics is an important contribution to the worldwide problem of antibiotic resistance. Consultations between clinicians and patients with ARIs are well-suited for shared decision making (SDM) because of the antibiotic benefit-harm trade-off. However, little research has analysed the extent and nature of SDM in consultations in the context of ARIs, including what and how antibiotic benefits and harms are communicated. There is also limited research that has explored patients’ understanding of antibiotic resistance, its consequences, or whether patients consider its threat when deciding whether to use antibiotics for ARIs.Aims— This thesis aimed to explore: patient-clinician communication, including the use of SDM, of antibiotic benefits and harms (including antibiotic resistance as one of the harms during ARI consultations); patients’ understanding of antibiotic resistance and aspects of it (such as resistance reversibility and resistance spread among family members); and how these influence patients’ attitudes towards antibiotic use. Investigating these aims also required updating the current evidence about resistance development and decay by performing a systematic review.
Methods— Four interrelated studies were conducted. Study 1 was an observational study in Australian general practices, nested within an ongoing cluster randomised trial of patient decision aids. In this study, consultations were audio-recorded, and the extent and nature of SDM in consultations between general practitioners (GPs) and patients with ARIs were subsequently analysed. Antibiotic benefits and harms communication, with and without the use of patient decision aids, was also explored. Study 2 was a qualitative study which used semi-structured interviews to explore patients’ understanding of antibiotic resistance, and related aspects, in a sub-sample of patients with ARIs who presented to GPs in Study 1. Study 3 was a systematic review and meta-analysis that examined the development and decay of antibiotic resistance in community patients after antibiotic use. This review was hampered by poor reporting, which led to quantitative analysis (Study 4) that examined the quality of reporting of studies included in Study 3 using checklists developed from existing reporting guidelines.
Results— Study 1 analysed 36 GP-patient consultations and found the extent of observer-assessed SDM between GPs and patients with ARIs was generally low (mean (SD) total observing patient involvement in decision making (OPTION12) score= 29.4 (12.5; 100-point scale). When patient decision aids were used (n=15 consultations), a balanced discussion of antibiotic benefits and harms occurred more often and was more comprehensive, with antibiotic resistance mentioned in 10 (67%) of these consultations. When decision aids were not used (n=21), antibiotic harms were rarely mentioned (n=1, 5%) and antibiotic resistance was never mentioned.
Study 2 revealed five key themes about people’s understanding and consideration of antibiotic resistance: 1) antibiotic use is seen as the main cause of resistance, but what it is that becomes resistant is poorly understood; 2) resistance is perceived as a future 'big problem' for the community, with little appreciation of the individual impact of, or contribution to it; 3) poor awareness that resistance can spread between family members, but concern that it can; 4) low awareness that resistance can decay with time and variable impact of this knowledge on attitudes towards future antibiotic use; and 5) antibiotics are perceived as sometimes necessary, with some awareness and consideration of their harms.
The systematic review (Study 3) included 25 studies (16,353 children and 1,461 adults). The review showed that antibiotic resistance in Streptococcus pneumoniae initially increased fourfold after penicillin-class antibiotic exposure, but fell after one month (OR 1.7, 95% CI 1.3–2.1). For cephalosporins, the odds of isolating resistant bacteria was lower than for penicillins directly after exposure, but after one month returned to similar odds as it did for the penicillins. Macrolides were also associated with increased antibiotic resistance immediately after use, which persisted for at least three months (OR 8.1, 95% CI 4.6–14.2, from controlled studies and OR 2.3, 95% CI 0.6–9.4, from time-series studies). Resistance in Haemophilus influenzae after penicillins was not significantly increased initially, but was at one month (OR 3.4, 95% CI 1.5–7.6), before falling to insignificant levels by three months. Data at three months was sparse for cephalosporins and macrolides.
Study 4 showed varied reporting quality of studies included in the previous systematic review. The mean percentage (SD, range) of studies that adequately described all the checklist items was 59% for RCTs (14%, 36%–84%) and 52% for prospective cohort studies (17%, 13%–70%). Aspects of the studies, such as the sampling procedures used, and rationale for the study, were described in most studies, although specific details (such as about blinding, and the actual incidence of resistant and susceptible isolates analysed at each time-point) were missing in many.
Conclusions and Implications— These studies highlighted the potential benefits that would arise from an increase in the proportion of consultations between clinicians and patients with ARIs in which SDM occurs. A balanced discussion, including how resistance is a potential harm of antibiotics, and what the possible consequences of this are, but that resistance decays with time (even if faster than previously reported), might lead to better engagement with patients about antibiotics. Patient decision aids are one method of assisting in this. Overall, addressing this need may reduce patients’ desire for, and use of, antibiotics for ARIs, but this needs empirically testing with further research. Moreover, research reporting antibiotic resistance needs to be improved at all levels from randomised trials to systematic reviews and other guiding documents. Establishing the need to consider the collection and aggregation of expert opinion to develop a globally endorsed reporting checklist for better reporting of antibiotic resistance in studies with prospective designs. Simultaneous measures to tackle antibiotic resistance, from communication to reporting, need to be implemented, to avoid living in a time when a simple prick injury could lead to death from an untreatable infection.
| Date of Award | 15 Jun 2019 |
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| Original language | English |
| Supervisor | Tammy Hoffmann (Supervisor) & Christopher Bernard Del Mar (Supervisor) |