PhD In Population Medicine - Antimicrobial stewardship for asthma exacerbation

This project addresses the priority area antimicrobial resistance (AMR), which is a key public health threat. Use of antibiotics drives AMR and most antibiotics are prescribed in primary care. Previous research and antimicrobial stewardship activities have addressed overuse of antibiotics for many conditions, but antibiotic use of asthma exacerbations is under-researched. More than one in ten people have a diagnosis of asthma at some point. Most asthma exacerbations are not caused by bacterial infections, systematic reviews of poor quality studies have not found convincing evidence of benefit from antibiotic treatment, and guidelines recommend against antibiotic treatment, but around half of GP consultations for asthma exacerbations are treated with antibiotics. This project aims to better describe the use of antibiotics for asthma exacerbations (including children who are prescribed asthma medications but do not have a diagnosis of asthma), determine the effect of antibiotics on reducing serious outcomes such as pneumonia and hospital admissions in people with asthma exacerbations, and understand the factors leading to antibiotic prescribing for asthma exacerbations in primary care.

The project will involve several epidemiological studies using routinely collected, linked electronic health data, and two studies exploring the knowledge, attitudes, practice and preferences driving antibiotic prescribing behaviour for asthma exacerbations amongst primary care clinicians. The first epidemiological study will be a cohort study aiming to describe the effect of having a diagnosis of asthma on the incidence of antibiotic prescribing, overall and by subgroups. This will help define the extent of the problem, identify specific subgroups for targeting, and describe the amount of variation by general practice. The second epidemiological study will be similar, but will address the use of antibiotics in children who use asthma medications but do not have a diagnosis of asthma. The third epidemiological study will evaluate the effects of antibiotic treatment for acute exacerbations of asthma on the risk of serious outcomes using an instrumental variable approach to control for unmeasured confounders. The project will also involve using both a knowledge, attitudes and practice (KAP) survey and a discrete choice experiment (DCE) to understand the triggers for prescribing amongst primary care clinicians.

This project will benefit people with asthma and their parents/carers, clinicians providing their care, and guideline developers, policy makers, public health experts and researchers by describing current use and how it deviates from guidance, describing variation in practice and the populations where prescribing rates are greatest, and assessing the effects of prescribing antibiotics on important outcomes such as pneumonia diagnoses and admissions for respiratory illness. Understanding the clinician knowledge, attitude, practice and preferences that drive antibiotic prescribing will help clinicians, healthcare managers and guideline developers, and will be essential to researchers and others designing interventions aimed at rationalising antibiotic use. Addressing the overuse of antibiotics in people with asthma will help reduce the selective pressures driving AMR, and will also reduce the risk of side effects, resistant infections and changes to normal flora, for the individuals affected.