title: Advancing knowledge of factors affecting the personalisation of airway clearance in bronchiectasis
Creators: name: Franks, Lisa J
Publisher: name: Griffith University
Year: 2022
Subjects: subject: Bronchiectasis
subject: Airway clearance techniques
subject: Positive expiratory pressure device
subject: PEP
subject: physiotherapy
subject: Flutter
subject: Acapella
subject: Pari PEP s
subject: Aerobika
subject: airway clearance

description: Bronchiectasis is a chronic and progressive lung disease associated with cough, sputum, and respiratory infection. The increasing burden on healthcare systems has led to renewed interest in clinical trials and developing therapies for this patient population. Airway clearance techniques (ACTs) are recommended as an integral part of management to facilitate secretion removal, improve symptoms and health-related quality of life (HRQOL). Guidelines recommend that ACTs should be personalised to improve outcomes. Our understanding about ACTs in bronchiectasis however remains limited. Currently there are no definitive guidelines on the optimal prescription of ACTs. Personalised prescription appears to be dependent upon clinical expertise, local training, and workplace culture. Significant knowledge gaps exist in literature regarding optimisation of ACTs for individuals with bronchiectasis. The overarching aim of this thesis was to enhance the personalised prescription of ACTs in bronchiectasis. Four studies were completed. The first study commenced at the airway clearance device itself and the properties of different commonly prescribed devices. The second study summarised outcome measures used in ACT studies and the final two studies examined separately the patient and physiotherapist perspectives of ACTs. Positive expiratory pressure (PEP) devices are a type of ACT device widely used in clinical settings. The comparative performance characteristics of these devices remain unknown. Study One (Chapter Three) was an experimental bench study which compared the performance characteristics (mean PEP, peak PEP, amplitude PEP and oscillation frequency) of six different PEP devices by varying resistance and flow. Results showed the performance characteristics of the devices differed across flows and resistance settings. Some commonly used devices (e.g. Acapella Choice, Acapella DH, Aerobika and Pari PEP S) were flow-dependent, whilst the performance characteristics of other devices (e.g. Acapella DM and Flutter) were independent of flow. Varying flow or resistance typically maintained or increased the production of mean, peak, and amplitude PEP and oscillation frequency. The clinical implications of the small but significant differences in performance characteristics of these PEP devices requires further investigation. Whilst ACTs are recommended for individuals with bronchiectasis, many trials have demonstrated inconsistent benefits or failed to reach their primary outcome. The narrative review of Study Two (Chapter Four) documented the most common clinical and patient-related outcome measures used to evaluate the efficacy of ACTs in bronchiectasis. The review included 27 published studies and 1 abstract. The most common clinical outcome measures were sputum volume (n = 23), lung function (n = 17) and pulse oximetry (n = 9). The most common patient-related outcomes were HRQOL (St George Respiratory Questionnaire, n = 4), cough-related quality of life (QOL) (Leicester Cough Questionnaire, n = 4) and dyspnoea (Borg / modified Borg scale, n = 8). This review highlighted the large heterogeneity in outcome measures used in ACT trials to date and recommended guidance on standardising the most important clinical and patient-related outcome measures for this patient population. With standardised outcome measures in place, the efficacy of different interventions can be compared leading to improved personalisation of ACTs in bronchiectasis. Even though ACTs are recommended in bronchiectasis, data suggests the use of and adherence to ACTs is poor. Study Three (Chapter Five) identified patient perceptions regarding ACTs, the barriers and facilitators of ACTs, and factors affecting adherence. A multi-centre qualitative study using in-depth semi-structured interviews of 24 individuals with bronchiectasis was undertaken. The main facilitators of using ACTs included a perceived health and QOL benefit, a tailored approach to ACTs and the use of self-management strategies. Main barriers to ACTs included lack of time and motivation, a lack of access to resources and, surprisingly, a lack of perceived health benefit. Several suggestions were also made that may help promote adherence including combining and trialling different ACTs, receiving regular ACT reviews and education from physiotherapists, and having good social support. Taking another perspective, Study Four (Chapter Six) examined physiotherapist perceptions of ACTs in both inpatients and outpatients with bronchiectasis. This was a single-centre qualitative study that used in-depth semi-structured interviews with eleven physiotherapists who treated individuals with bronchiectasis. The study revealed that physiotherapists regularly and routinely prescribe ACTs for inpatients and outpatients with bronchiectasis, however the clinical decision-making regarding optimal ACT prescription was regarded as complex. Main themes influencing ACT prescription included organisational factors (workload, scope of service, access to resources / ACTs, financial burden of ACT); patient-related factors (symptom severity, finances, disease-specific knowledge, social commitments, timing of ACT, clinical setting, perceived benefit, and motivation); and physiotherapist / profession-related factors (clinical experience, access to professional support and education, awareness of evidence of ACTs and evaluating ACT effectiveness). In summary, the work presented in this thesis serves to refine the prescription of ACTs for bronchiectasis. There are different ACT devices prescribed by clinicians that have different performance characteristics. Due consideration of these performance characteristics needs to be given when prescribing ACTs. The marked heterogeneity of study designs and outcome measures used to evaluate ACTs in bronchiectasis has made the interpretation of different ACT intervention studies difficult. There is a need for standardisation of outcome measures for ACTs that will enable future intervention studies to be more comparable. Individuals with bronchiectasis and physiotherapists prescribing ACTs describe multiple factors that may impact upon adherence to ACTs. For patients, these barriers and facilitators centre on improving HRQOL. For the prescribing physiotherapist, airway clearance centres on the complexity of the patient and intervention. The results from the four studies in this doctoral program should be considered by physiotherapists to assist the personalised prescription of ACTs with the ultimate outcome of improving adherence and HRQOL for individuals with bronchiectasis.