Active Cycles of Breathing Technique (ACBT) versus conventional chest physical therapy on airway clearance in bronchiectasis – A crossover trial

Evaluation of outcome reporting in clinical trials of physiotherapy in bronchiectasis: The first stage of core outcome set development

INTRODUCTION

The aim of this study is to explore outcomes currently reported in physiotherapy trials for bronchiectasis and investigate the level of consistency in outcome reporting. This mapping of outcomes will be used to inform the development of a core outcome set (COS) for physiotherapy research in bronchiectasis. Outcomes reported in randomised clinical trials (RCTs) and RCT protocols were reviewed and evaluated. We included trials with physiotherapy as the main intervention, including pulmonary rehabilitation, exercise prescription, airway clearance, positive expiratory pressure devices, breathing training, self-management plans, and home exercise program. Medline, CINAHL, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), and the physiotherapy evidence database (PEDro) were searched from inception using a prespecified search strategy. Records including adult patients with bronchiectasis were included. Outcomes were listed verbatim and categorised into domains based on a pre-specified system, frequency of reporting and sources of variation were inspected.

RESULTS

Of 2158 abstracts screened, 37 trials (1202 participants) and 17 trial protocols were identified. Eighteen different physiotherapy techniques were investigated. A total of 331 outcomes were reported. No single outcome was reported by all trials. The most reported outcomes were lung function (27 trials, 50%), health related quality of life (26 trials, 48.1%), and dyspnoea (18 trials, 33.3%). A list of 104 unique outcomes covering 23 domains was created. Trials focus on physiological outcomes, mainly those related to respiratory system functions. Outcomes related to functioning and life impact are often neglected.

CONCLUSION

Outcome reporting in physiotherapy research for bronchiectasis was found to be inconsistent in terms of choosing and defining outcomes. Developing a core outcome set in this area of research is needed to facilitate aggregation of future trial results in systematic reviews that will in turn inform the strength of evidence for the effectiveness of physiotherapy. Outcome choice should include all stakeholders, including patients.

TRIAL REGISTRATION

This study is registered in the PROSPERO registry under the number CRD42021266247.

The effectiveness of the active cycle of breathing technique in patients with chronic respiratory diseases: A systematic review

BACKGROUND

Active cycle breathing technique (ACBT), which includes cycle of breathing control, thoracic expansion exercises and forced expiratory technique (FET), appears to have beneficial effects in patients with a variety of respiratory diseases. This systematic review provides an update on the new related studies, expanding the evidence base through the last 12 years and specifically evaluating the effectiveness of ACBT on pulmonary function-related outcome variables in patients with chronic respiratory diseases.

METHODS

MEDLINE/Pubmed, PEDro, and Cochrane Library for Randomized Controlled Trials were searched between September 2008 and December 2021, in continuance of a previous systematic review, to identify randomized clinical trials and/or crossover studies comparing ACBT to other respiratory treatment techniques in patients with chronic obstructive pulmonary diseases, cystic fibrosis, or bronchiectasis.

RESULTS

Eleven studies were included and the quality of most of them was moderate to good. The outcomes most frequently assessed were forced expiratory volume in 1 s (FEV₁), sputum wet weight, forced vital capacity (FVC), and peak expiratory flow rate. Secondary outcomes were quality of life and dyspnea. Various comparators were identified and most of them assessed the ACBT as an effective method in comparison with other respiratory treatment modalities. Most studies revealed that ACBT/FET had at least an equally beneficial short-term effect on sputum wet weight, FEV₁ and FVC compared to other treatment methods.

CONCLUSION

The results of this updating review reinforced the data of a previous systematic review regarding the beneficial impact of ACBT for the short-term improvement in respiratory tract secretions clearance and pulmonary function. ACBT is effective in increasing the expectorated sputum volume, in reducing viscoelasticity of the secretion and in relieving symptoms such as dyspnea.

[Multidisciplinary Management of Non-cystic-fibrosis Bronchiectasis - State of the Art]

Bronchiectasis is a mostly irreversible bronchial dilatation induced by a destruction of elastic and muscular fibers of the bronchial wall. Radiological criteria of bronchiectasis are met, when the inner diameter of the bronchial wall surpasses the outer diameter of the accompanying pulmonary artery. Its incidence increases with age, even though it often lacks true clinical signs of disease. Only when it is accompanied by cough, expectorations and recurring bronchopulmonary infections, it can be considered a true bronchiectatic disease. Cystic fibrosis (CF) is one of its preeminent triggers, but certainly plays a particular role in this entity, which is why the terminus of "non-CF-bronchiectasis" was coined in the first place.Multidisciplinary management consists in extensive diagnostic work-up, treatment of potential triggers of bronchiectasis and supportive care in form of vaccination programs, secretolysis and pulmonary rehabilitation, as well as antibiotic treatment of pulmonary exacerbations.Surgical treatment has to be considered a last resort in case of hemoptysis, recurring severe pneumonia or secondary aspergilloma with complete resection of all pathological findings, ideally by minimally-invasive approach.

Measuring airway clearance outcomes in bronchiectasis: a review

While airway clearance techniques (ACTs) are recommended for individuals with bronchiectasis, many trials have demonstrated inconsistent benefits or failed to reach their primary outcome. This review determined the most common clinical and patient-reported outcome measures used to evaluate the efficacy of ACTs in bronchiectasis. A literature search of five databases using relevant keywords and filtering for studies published in English, up until the end of August 2019, was completed. Studies included randomised controlled trials, using crossover or any other trial design, and abstracts. Studies were included where the control was placebo, no intervention, standard care, usual care or an active comparator. Adults with bronchiectasis not related to cystic fibrosis were included. Extracted data comprised study authors, design, duration, intervention, outcome measures and results. The search identified 27 published studies and one 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-reported outcomes were health-related quality of life (measured with St George's Respiratory Questionnaire, n=4), cough-related quality of life (measured with Leicester Cough Questionnaire, n=4) and dyspnoea (measured with Borg/modified Borg scale, n=8). Sputum volume, lung function, dyspnoea and health- and cough-related quality of life appear to be the most common clinical and patient-reported measures of airway clearance treatment efficacy.

Respiratory physiotherapy in intensive care unit: Bibliographic review

INTRODUCTION AND AIMS

Patients in intensive care unit are susceptible to complications due to different causes (underlying disease, immobilisation, infection risk…) The current main intervention in order to prevent these complications is respiratory physiotherapy, a common practice for nurses on a daily basis. Therefore, we decided to carry out this bibliographic review to describe the most efficient respiratory physiotherapy methods for the prevention and treatment of lung complications in patients in intensive care, taking into account the differences between intubated and non-intubated patients.

METHODOLOGY

The bibliographic narrative review was carried out on literature available in Pubmed, Cinahl and Cochrane Library. The established limits were language, evidence over the last 15 years and age.

RESULTS

Techniques involving lung expansion, cough, vibration, percussion, postural drainage, incentive inspirometry and oscillatory and non-oscillatory systems are controversial regarding their efficacy as respiratory physiotherapy methods. However, non-invasive mechanical ventilation shows clear benefits. In the case of intubated patients, manual hyperinflation and secretion aspirations are highly efficient methods for the prevention of the potential complications mentioned above. In this case, other RP methods showed no clear efficiency when used individually.

DISCUSSION AND CONCLUSIONS

Non-invasive mechanical ventilation (for non-intubated patients) and manual hyperinflation (for intubated patients) proved to be the respiratory physiotherapy methods with the best results. The other techniques are more controversial and the results are not so clear. In both types of patients this literature review suggests that combined therapy is the most efficient.

Positive expiratory pressure therapy versus other airway clearance techniques for bronchiectasis

BACKGROUND

People with bronchiectasis experience chronic cough and sputum production and require the prescription of airway clearance techniques (ACTs). A common type of ACT prescribed is positive expiratory pressure (PEP) therapy. A previous review has suggested that ACTs including PEP therapy are beneficial compared to no treatment in people with bronchiectasis. However, the efficacy of PEP therapy in a stable clinical state or during an acute exacerbation compared to other ACTs in bronchiectasis is unknown.

OBJECTIVES

The primary aim of this review was to determine the effects of PEP therapy compared with other ACTs on health-related quality of life (HRQOL), rate of acute exacerbations, and incidence of hospitalisation in individuals with stable or an acute exacerbation of bronchiectasis.Secondary aims included determining the effects of PEP therapy upon physiological outcomes and clinical signs and symptoms compared with other ACTs in individuals with stable or an acute exacerbation of bronchiectasis.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register of Trials, PEDro and clinical trials registries from inception to February 2017 and we handsearched relevant journals.

SELECTION CRITERIA

Randomised controlled parallel and cross-over trials that compared PEP therapy versus other ACTs in participants with bronchiectasis.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as outlined by Cochrane.

MAIN RESULTS

Nine studies involving 213 participants met the inclusion criteria, of which seven were cross-over in design. All studies included adults with bronchiectasis, with eight including participants in a stable clinical state and one including participants experiencing an acute exacerbation. Eight studies used oscillatory PEP therapy, using either a Flutter or Acapella device and one study used Minimal PEP therapy. The comparison intervention differed between studies. The methodological quality of studies was poor, with cross-over studies including suboptimal or no washout period, and a lack of blinding of participants, therapists or personnel for outcome measure assessment in most studies. Clinical heterogeneity between studies limited meta-analysis.Daily use of oscillatory PEP therapy for four weeks was associated with improved general health according to the Short-Form 36 questionnaire compared to the active cycle of breathing technique (ACBT). When applied for three sessions over one week, minimal PEP therapy resulted in similar improvement in cough-related quality of life as autogenic drainage (AD) and L'expiration Lente Totale Glotte Ouverte en Decubitus Lateral (ELTGOL). Oscillatory PEP therapy twice daily for four weeks had similar effects on disease-specific HRQOL (MD -0.09, 95% CI -0.37 to 0.19; low-quality evidence). Data were not available to determine the incidence of hospitalisation or rate of exacerbation in clinically stable participants.Two studies of a single session comparison of oscillatory PEP therapy and gravity-assisted drainage (GAD) with ACBT had contrasting findings. One study found a similar sputum weight produced with both techniques (SMD 0.54g (-0.38 to 1.46; 20 participants); the other found greater sputum expectoration with GAD and ACBT (SMD 5.6 g (95% CI 2.91 to 8.29: 36 participants). There was no difference in sputum weight yielded between oscillatory PEP therapy and ACBT with GAD when applied daily for four weeks or during an acute exacerbation. Although a single session of oscillatory PEP therapy was associated with less sputum compared to AD (median difference 3.1 g (95% CI 1.5 to 4.8 g; one study, 31 participants), no difference between oscillatory PEP therapy and seated ACBT was evident. PEP therapy had a similar effect on dynamic and static measures of lung volumes and gas exchange as all other ACTs. A single session of oscillatory PEP therapy (Flutter) generated a similar level of fatigue as ACBT with GAD, but greater fatigue was noted with oscillatory PEP therapy compared to ACBT alone. The degree of breathlessness experienced with PEP therapy did not differ from other techniques. Among studies exploring adverse events, only one study reported nausea with use of oscillatory PEP therapy.

AUTHORS' CONCLUSIONS

PEP therapy appears to have similar effects on HRQOL, symptoms of breathlessness, sputum expectoration, and lung volumes compared to other ACTs when prescribed within a stable clinical state or during an acute exacerbation. The number of studies and the overall quality of the evidence were both low. In view of the chronic nature of bronchiectasis, additional information is needed to establish the long-term clinical effects of PEP therapy over other ACTs for outcomes that are important to people with bronchiectasis and on clinical parameters which impact on disease progression and patient morbidity in individuals with stable bronchiectasis. In addition, the role of PEP therapy during an acute exacerbation requires further exploration. This information is necessary to provide further guidance for prescription of PEP therapy for people with bronchiectasis.

[Manual airway clearance techniques in adults and adolescents: What level of evidence?]

BACKGROUND

The aim of this systematic literature review was to grade the levels of evidence of the most widely used manual airway clearance techniques.

METHODS

A literature search was conducted over the period 1995-2014 from the Medline, PEDro, ScienceDirect, Cochrane Library, REEDOC and kinedoc databases, with the following keywords: "postural drainage", "manual vibrations", "manual chest percussion", "directed cough", "increased expiratory flow", "ELTGOL", "autogenic drainage" and "active cycle of breathing technique".

RESULTS

Two-hundred and fifty-six articles were identified. After removing duplicates and reading the titles and abstracts, 63 articles were selected, including 9 systematic reviews. This work highlights the lack of useful scientific data and the difficulty of determining levels of evidence for manual airway clearance techniques. Techniques were assessed principally with patients with sputum production (cystic fibrosis, DDB, COPD, etc.). It also shows the limited pertinence of outcome measures to quantify congestion and hence the efficacy of airway clearance techniques.

CONCLUSION

The 1994 consensus conference summary table classifying airway clearance techniques according to physical mechanism provides an interesting tool for assessment, grouping together techniques having identical mechanisms of action. From the findings of the present systematic review, it appears that only ELTGOL, autogenic drainage and ACBT present levels of evidence "B". All other techniques have lower levels of evidence.

LEVEL OF EVIDENCE

II.

Airway clearance techniques for bronchiectasis

BACKGROUND

People with non-cystic fibrosis bronchiectasis commonly experience chronic cough and sputum production, features that may be associated with progressive decline in clinical and functional status. Airway clearance techniques (ACTs) are often prescribed to facilitate expectoration of sputum from the lungs, but the efficacy of these techniques in a stable clinical state or during an acute exacerbation of bronchiectasis is unclear.

OBJECTIVES

Primary: to determine effects of ACTs on rates of acute exacerbation, incidence of hospitalisation and health-related quality of life (HRQoL) in individuals with acute and stable bronchiectasis. Secondary: to determine whether:• ACTs are safe for individuals with acute and stable bronchiectasis; and• ACTs have beneficial effects on physiology and symptoms in individuals with acute and stable bronchiectasis.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register of trials from inception to November 2015 and PEDro in March 2015, and we handsearched relevant journals.

SELECTION CRITERIA

Randomised controlled parallel and cross-over trials that compared an ACT versus no treatment, sham ACT or directed coughing in participants with bronchiectasis.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by The Cochrane Collaboration.

MAIN RESULTS

Seven studies involving 105 participants met the inclusion criteria of this review, six of which were cross-over in design. Six studies included adults with stable bronchiectasis; the other study examined clinically stable children with bronchiectasis. Three studies provided single treatment sessions, two lasted 15 to 21 days and two were longer-term studies. Interventions varied; some control groups received a sham intervention and others were inactive. The methodological quality of these studies was variable, with most studies failing to use concealed allocation for group assignment and with absence of blinding of participants and personnel for outcome measure assessment. Heterogeneity between studies precluded inclusion of these data in the meta-analysis; the review is therefore narrative.One study including 20 adults that compared an airway oscillatory device versus no treatment found no significant difference in the number of exacerbations at 12 weeks (low-quality evidence). Data were not available for assessment of the impact of ACTs on time to exacerbation, duration or incidence of hospitalisation or total number of hospitalised days. The same study reported clinically significant improvements in HRQoL on both disease-specific and cough-related measures. The median difference in the change in total St George's Respiratory Questionnaire (SGRQ) score over three months in this study was 7.5 units (P value = 0.005 (Wilcoxon)). Treatment consisting of high-frequency chest wall oscillation (HFCWO) or a mix of ACTs prescribed for 15 days significantly improved HRQoL when compared with no treatment (low-quality evidence). Two studies reported mean increases in sputum expectoration with airway oscillatory devices in the short term of 8.4 mL (95% confidence interval (CI) 3.4 to 13.4 mL) and in the long term of 3 mL (P value = 0.02). HFCWO improved forced expiratory volume in one second (FEV1) by 156 mL and forced vital capacity (FVC) by 229.1 mL when applied for 15 days, but other types of ACTs showed no effect on dynamic lung volumes. Two studies reported a reduction in pulmonary hyperinflation among adults with non-positive expiratory pressure (PEP) ACTs (difference in functional residual capacity (FRC) of 19%, P value < 0.05; difference in total lung capacity (TLC) of 703 mL, P value = 0.02) and with airway oscillatory devices (difference in FRC of 30%, P value < 0.05) compared with no ACTs. Low-quality evidence suggests that ACTs (HFCWO, airway oscillatory devices or a mix of ACTs) reduce symptoms of breathlessness and cough and improve ease of sputum expectoration compared with no treatment (P value < 0.05). ACTs had no effect on gas exchange, and no studies reported effects of antibiotic usage. Among studies exploring airway oscillating devices, investigators reported no adverse events.

AUTHORS' CONCLUSIONS

ACTs appear to be safe for individuals (adults and children) with stable bronchiectasis and may account for improvements in sputum expectoration, selected measures of lung function, symptoms and HRQoL. The role of these techniques in acute exacerbation of bronchiectasis is unknown. In view of the chronic nature of bronchiectasis, additional data are needed to establish the short-term and long-term clinical value of ACTs for patient-important outcomes and for long-term clinical parameters that impact disease progression in individuals with stable bronchiectasis, allowing further guidance on prescription of specific ACTs for people with bronchiectasis.

Interventions for bronchiectasis: an overview of Cochrane systematic reviews

BACKGROUND

Bronchiectasis is a chronic respiratory disease characterised by abnormal dilatation of the bronchi, and presents typically with a chronic productive cough (or chronic wet cough in children) and recurrent infective exacerbations. It significantly impacts daily activities and quality of life, and can lead to recurrent hospitalisations, severe lung function impairment, respiratory failure and even death.

OBJECTIVES

To provide an overview of the efficacy and safety of interventions for adults and children with bronchiectasis from Cochrane reviews.To identify gaps in the evidence base that will inform recommendations for new research and reviews, and to summarise information on reported outcomes and make recommendations for the reporting of standard outcomes in future trials and reviews.

METHODS

We included Cochrane reviews of non-cystic fibrosis (CF) bronchiectasis. We searched the Cochrane Database of Systematic Reviews. The search is current to 11 February 2015. We also identified trials that were potentially eligible for, but not currently included in, published reviews to make recommendations for new Cochrane reviews. We assessed the quality of included reviews using the AMSTAR criteria. We presented an evidence synthesis of data from reviews alongside an evidence map of clinical trials and guideline data. The primary outcomes were exacerbations, lung function and quality of life.

MAIN RESULTS

We included 21 reviews but extracted data from, and rated the quality of, only nine reviews that reported results for people with bronchiectasis alone. Of the reviews with no usable data, two reviews included studies with mixed clinical populations where data were not reported separately for people with bronchiectasis and 10 reviews did not contain any trials. Of the 40 studies included across the nine reviews, three (number of participants nine to 34) included children. The studies ranged from single session to year-long studies. Each review included from one to 11 trials and 28 (70%) trials in the overview included 40 or fewer participants. The total number of participants included in reviews ranged from 40 to 1040. The age range of adult participants was from 36 to 73 years and children ranged from six to 16 years. The proportion of male participants ranged from 21% to 72%. Where reported, mean baseline forced expiratory volume in one second (FEV1) ranged from 1.17 L to 1.66 L and from 47% to 88% predicted. Most of the reviews had search dates older than two years.We have summarised the published evidence as outlined in Cochrane reviews, but it was not possible to draw definitive conclusions. There was inconclusive evidence on the use of long-term antibiotics and nebulised hypertonic saline for reducing exacerbation frequency and evidence that human deoxyribonuclease (RhDNase) increases exacerbation frequency. Improvements in lung function were reported for inhaled corticosteroids (ICS) though this was small and not clinically relevant. Evidence of benefit for hyperosmolar agents and mucolytics was inconclusive. There was limited evidence of improvements in quality of life with airway clearance techniques and physical therapy but evidence of benefit for hyperosmolar agents was inconclusive. Secondary outcomes were not clearly reported in all trials in the included reviews. Improvements in dyspnoea, wheeze and cough-free days were reported for small trials of ICS and LABA (long-acting beta2-agonsts)/ICS and cough reduction was also reported for a small bromhexine trial. Reduction in sputum production was reported for long-term antibiotics and airway clearance techniques but evidence of benefit for hyperosmolar agents was inconclusive.Adverse events were included as outcomes in seven reviews. The review of long-term (four weeks to one year) prophylactic courses of antibiotics reported significantly more cases of wheeze (Peto odd ratio (OR) 8.56, 95% confidence intervals (CI) 1.63 to 44.93), dyspnoea (12 versus three, P value = 0.01) and chest pain (seven versus zero, P value = 0.01) from the same trial (74 participants) but no differences in occurrence of diarrhoea, rash or number of withdrawals. In the review of mucolytics versus placebo, relevant outcomes were not reported for erdosteine comparisons and no significant adverse effects were reported for bromhexine, though adverse events were associated with RhDNase (OR 28.19, 95% CI 3.77 to 210.85, 1 study). Of the remaining five reviews, adverse events were not reported in the single trials included in the ICS review or the physical therapy review and the impact of adverse events in the single trial included in the inhaled LABA/ICS combination versus ICS review were unclear. The reviews of short-term courses of antibiotics and inhaled hyperosmolar agents reported no significant differences in occurrence of adverse events. Fewer admissions to hospital were reported for long-term antibiotics, but this outcome was not reported in all reviews. No reviews reported differences in mortality, but again this outcome was not included in all reviews.We did not explicitly include antibiotic resistance as an outcome in the review, but this was unclear in the Cochrane reviews and evidence from other trials should be considered.We rated all reviews as high quality (AMSTAR), though opportunities for improved reporting (e.g. summary of findings and GRADE evaluation of the evidence) were identified for inclusion in future updates of the reviews. However, the majority of trials were not high quality and confidence in the effects of treatments, therefore, requires additional evidence from larger and more methodologically robust trials. We evaluated the overall coverage of important topics in bronchiectasis by mapping the quality of the current evidence base against published guidelines and identifying high priority areas for new research on; use of short-course and long-term antibiotics, ICS and oral corticosteroids, inhaled hyperosmolars, mucolytics, and use of airway clearance techniques.

AUTHORS' CONCLUSIONS

This overview clearly points to significant opportunities for further research aimed at improving outcomes for people with bronchiectasis. We have highlighted important endpoints for studies (particularly exacerbations, quality of life and lung function), and areas of clinical practice that are in most urgent need of evidence-based support (including long-term antibiotics, ICSs and mucolytics).As the evidence is confined to small trials of short duration, it is not currently possible to assess the balance between the benefits and potential harms of treatments for bronchiectasis.

Airway clearance techniques for bronchiectasis

BACKGROUND

People with non-cystic fibrosis bronchiectasis commonly experience chronic cough and sputum production and these features may be associated with progressive decline in clinical status. Airway clearance techniques (ACTs) are often prescribed to facilitate expectoration of sputum from the lungs, but the efficacy of these techniques in a stable clinical state or during an acute exacerbation of bronchiectasis is unclear.

OBJECTIVES

Primary: to determine the effects of ACTs on the rate of acute exacerbations, incidence of hospitalisation and health-related quality of life in individuals with acute and stable bronchiectasis.Secondary: to determine whether a) ACTs are safe for individuals with acute and stable bronchiectasis and b) ACTs have beneficial effects on physiology and symptoms in individuals with acute and stable bronchiectasis.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register of trials from inception to October 2012, PEDro in October 2012 and handsearched relevant journals.

SELECTION CRITERIA

Randomised controlled parallel and cross-over trials that compared an ACT to no treatment, sham ACT or directed coughing in participants with bronchiectasis.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS

Five studies involving 51 participants met the inclusion criteria of the review, all of which were cross-over design. Four studies were on adults with stable bronchiectasis, and the other study was on clinically stable children with bronchiectasis. Three studies were single treatment sessions, two were longer-term studies. The interventions varied and some control groups received a sham intervention while others were inactive. The methodological quality of the studies was variable and the studies were not able to blind participants and personal. Heterogeneity between studies precluded these data from meta-analysis and the review was therefore narrative.One study on 20 adults comparing an airway oscillatory device with no treatment found no significant difference in the number of exacerbations at 12 weeks (low-quality evidence). No data were available to assess the impact of ACTs on the time to exacerbation, duration of, incidence of hospitalisation or total number of hospitalised days. The same study reported clinically significant improvements in health-related quality of life in both disease-specific and cough-related measures. While based on a small number of participants and the data were skewed, the median difference in the change in total St George's Respiratory Questionnaire (SGRQ) score over three months in this study was 8.5 units (P value = 0.005 (Wilcoxon), low-quality evidence). Two studies reported mean increases in volume of sputum expectorated with airway oscillatory devices in the short term of 8.4 mL (95% CI 3.4 to 13.4 mL) and in the long term of 3 mL (P value = 0.02), with no significant effect on lung function. One study reported an immediate reduction in pulmonary hyperinflation in adults with non-positive expiratory pressure (PEP) ACTs (difference in functional residual capacity (FRC) of 19%, P value < 0.05) and with airway oscillatory devices (difference in FRC of 30%, P value < 0.05) compared to no ACTs. A similar decrease in pulmonary hyperinflation (difference in FRC of 6%) was found in children using an airway oscillatory device for 3 months compared to sham therapy. No studies reported on the effects of gas exchange, people's symptoms or antibiotic usage.

AUTHORS' CONCLUSIONS

ACTs appear to be safe for individuals (adults and children) with stable bronchiectasis, where there may be improvements in sputum expectoration, selected measures of lung function and health-related quality of life. The role of these techniques in people with an acute exacerbation of bronchiectasis is unknown. In view of the chronic nature of bronchiectasis, more data are needed to establish the clinical value of ACTs over the short and long term on patient-important outcomes, including symptoms, on physiological outcomes which may clarify the rationale for each technique and on long-term parameters that impact on disease progression in individuals with stable bronchiectasis. This is necessary in order to provide further guidance of specific ACT prescription for people with bronchiectasis. It may also be important to establish the comparative effect of different types of ACTs in people with bronchiectasis.