Review question
Is conventional chest physiotherapy (CCPT) better than other methods of airway clearance for people with cystic fibrosis (CF)?
Key messages
Airway clearance techniques (ACTs) are a very important part of therapy in people with CF.
There are now lots of different types of ACTs, but there is still very little known about how good each one is and how they compare to each other.
The focus of this review was to compare CCPT (also known as traditional chest physiotherapy) with alternative ACTs.
What is cystic fibrosis?
CF is a life-limiting inherited disease affecting between 70,000 and 100,000 people worldwide. People with CF produce mucus in their lungs that can be thick, sticky and difficult to clear. This leads to repeated infections and lung damage. It is important to clear this mucus using medicines and various chest physiotherapy ACTs. CCPTs such as postural drainage, percussion and vibration, huffing and coughing have generally required assistance from someone else during treatments. Alternative ACTs such as active cycle of breathing techniques, forced expiration technique, autogenic drainage, positive expiratory pressure devices, oscillating positive expiratory pressure devices (e.g. Acapella, Aerobika, Flutter, RC-Cornet) or high-frequency chest compression and exercise are self-administered, which increases independence and flexibility.
What did we want to find out?
We wanted to compare how different ACTs affect lung function (how well the lungs work), respiratory exacerbations (flare-ups of lung disease), a person's preference, adherence (how well the person follows their doctor's advice), quality of life and impact on fitness levels.
What did we do?
We searched medical databases for well-designed studies comparing CCPT with other ACTs in people with CF. Studies selected people for one treatment or the other in a random or partly random way. We chose studies lasting longer than one week to allow enough time for treatments to have an impact on the outcomes we were interested in.
What did we find?
We found 21 studies with 778 people with CF aged from newborn to 45 years and with all levels of disease severity. The number of people included in each study ranged from 13 to 166. There were more females than males included in all but two studies.
Main results
The studies did not show that any alternative ACTs were better than CCPT in terms of lung function, respiratory exacerbations, a person's preference, adherence, quality of life and impact on fitness level. Studies in which participants had flare-ups of chest infections showed that lung function improved considerably after treatment, irrespective of the type of ACT. Longer-term studies showed smaller improvements or a decline in lung function. In 10 studies, participants preferred the chest physiotherapy techniques they could administer themselves, but, since the studies measured preference in different ways, we could not combine the individual study results in an analysis. Side effects from different ACTs tended to be rare, mild and resolved quickly. We cannot recommend any single treatment over another at this time.
What are the limitations of the evidence?
The quality of evidence varied greatly between the studies. We are not sure that the present evidence is able to answer the questions we were asking. We did not find enough evidence to confirm or exclude any differences between CCPT and alternative ACTs in terms of our outcome measures. Furthermore, data from our included studies did not show that any of the alternative ACTs were better than CCPT in people with CF. This may be because the studies did not report enough data for us to analyse, rather than confirming that the ACTs all worked equally well. There were differences in how the studies were run and how the researchers collected data, so this also makes it difficult to compare results. These differences included the number of people in the studies, length of time the studies lasted, location of the studies (e.g. in hospital or at home), types of ACTs used and outcomes measured by the researchers to assess the impact of the different techniques. In future studies it would be better if these factors were more similar to make it easier to compare results.
How up to date is this evidence?
We last searched the databases in June 2022.
We are uncertain whether CCPT has a more positive impact on respiratory function, respiratory exacerbations, individual preference, adherence, quality of life, exercise capacity and other outcomes when compared to alternative ACTs as the certainty of the evidence is very low.
There was no advantage in respiratory function of CCPT over alternative ACTs, but this may reflect insufficient evidence rather than real equivalence. Narrative reports indicated that participants prefer self-administered ACTs. This review is limited by a paucity of well-designed, adequately powered, long-term studies. This review cannot yet recommend any single ACT above others; physiotherapists and people with CF may wish to try different ACTs until they find an ACT that suits them best.
Cystic fibrosis (CF) is an inherited life-limiting disorder. Over time persistent infection and inflammation within the lungs contribute to severe airway damage and loss of respiratory function. Chest physiotherapy, or airway clearance techniques (ACTs), are integral in removing airway secretions and initiated shortly after CF diagnosis. Conventional chest physiotherapy (CCPT) generally requires assistance, while alternative ACTs can be self-administered, facilitating independence and flexibility. This is an updated review.
To evaluate the effectiveness (in terms of respiratory function, respiratory exacerbations, exercise capacity) and acceptability (in terms of individual preference, adherence, quality of life) of CCPT for people with CF compared to alternative ACTs.
We used standard, extensive Cochrane search methods. The latest search was 26 June 2022.
We included randomised or quasi-randomised controlled trials (including cross-over design) lasting at least seven days and comparing CCPT with alternative ACTs in people with CF.
We used standard Cochrane methods. Our primary outcomes were 1. pulmonary function tests and 2. number of respiratory exacerbations per year. Our secondary outcomes were 3. quality of life, 4. adherence to therapy, 5. cost–benefit analysis, 6. objective change in exercise capacity, 7. additional lung function tests, 8. ventilation scanning, 9. blood oxygen levels, 10. nutritional status, 11. mortality, 12. mucus transport rate and 13. mucus wet or dry weight.
We reported outcomes as short-term (seven to 20 days), medium-term (more than 20 days to up to one year) and long-term (over one year).
We included 21 studies (778 participants) comprising seven short-term, eight medium-term and six long-term studies. Studies were conducted in the USA (10), Canada (five), Australia (two), the UK (two), Denmark (one) and Italy (one) with a median of 23 participants per study (range 13 to 166). Participant ages ranged from newborns to 45 years; most studies only recruited children and young people. Sixteen studies reported the sex of participants (375 males; 296 females).
Most studies compared modifications of CCPT with a single comparator, but two studies compared three interventions and another compared four interventions. The interventions varied in the duration of treatments, times per day and periods of comparison making meta-analysis challenging. All evidence was very low certainty.
Nineteen studies reported the primary outcomes forced expiratory volume in one second (FEV1)and forced vital capacity (FVC), and found no difference in change from baseline in FEV1 % predicted or rate of decline between groups for either measure. Most studies suggested equivalence between CCPT and alternative ACTs, including positive expiratory pressure (PEP), extrapulmonary mechanical percussion, active cycle of breathing technique (ACBT), oscillating PEP devices (O-PEP), autogenic drainage (AD) and exercise. Where single studies suggested superiority of one ACT, these findings were not corroborated in similar studies; pooled data generally concluded that effects of CCPT were comparable to those of alternative ACTs.
CCPT versus PEP
We are uncertain whether CCPT improves lung function or has an impact on the number of respiratory exacerbations per year compared with PEP (both very low-certainty evidence). There were no analysable data for our secondary outcomes, but many studies provided favourable narrative reports on the independence achieved with PEP mask therapy.
CCPT versus extrapulmonary mechanical percussion
We are uncertain whether CCPT improves lung function compared with extrapulmonary mechanical percussions (very low-certainty evidence). The annual rate of decline in average forced expiratory flow between 25% and 75% of FVC (FEF25–75) was greater with high-frequency chest compression compared to CCPT in medium- to long-term studies, but there was no difference in any other outcome.
CCPT versus ACBT
We are uncertain whether CCPT improves lung function compared to ACBT (very low-certainty evidence). Annual decline in FEF25–75 was worse in participants using the FET component of ACBT only (mean difference (MD) 6.00, 95% confidence interval (CI) 0.55 to 11.45; 1 study, 63 participants; very low-certainty evidence). One short-term study reported that directed coughing was as effective as CCPT for all lung function outcomes, but with no analysable data. One study found no difference in hospital admissions and days in hospital for exacerbations.
CCPT versus O-PEP
We are uncertain whether CCPT improves lung function compared to O-PEP devices (Flutter device and intrapulmonary percussive ventilation); however, only one study provided analysable data (very low-certainty evidence). No study reported data for number of exacerbations. There was no difference in results for number of days in hospital for an exacerbation, number of hospital admissions and number of days of intravenous antibiotics; this was also true for other secondary outcomes.
CCPT versus AD
We are uncertain whether CCPT improves lung function compared to AD (very low-certainty evidence). No studies reported the number of exacerbations per year; however, one study reported more hospital admissions for exacerbations in the CCPT group (MD 0.24, 95% CI 0.06 to 0.42; 33 participants). One study provided a narrative report of a preference for AD.
CCPT versus exercise
We are uncertain whether CCPT improves lung function compared to exercise (very low-certainty evidence). Analysis of original data from one study demonstrated a higher FEV1 % predicted (MD 7.05, 95% CI 3.15 to 10.95; P = 0.0004), FVC (MD 7.83, 95% CI 2.48 to 13.18; P = 0.004) and FEF25–75 (MD 7.05, 95% CI 3.15 to 10.95; P = 0.0004) in the CCPT group; however, the study reported no difference between groups (likely because the original analysis accounted for baseline differences).