Advice
Clinical and technical evidence
Clinical and technical evidence
A literature search was carried out for this briefing in accordance with the interim process and methods statement. This briefing includes the most relevant or best available published evidence relating to the clinical effectiveness of the technology. Further information about how the evidence for this briefing was selected is available on request by contacting mibs@nice.org.uk.
Published evidence
Five studies are summarised in this briefing: 1 pilot randomised controlled trial, 1 retrospective review and 2 before-and-after studies involving 54 people with cerebral palsy in the US. Three of the studies were in children, 1 study included adults and children. An additional before-and-after study in the US included 36 people with motor neurone disease.
Table 1 summarises the clinical evidence as well as its strengths and limitations.
Overall assessment of the evidence
The evidence for the effectiveness of The Vest for airway clearance in people with complex neurological needs is limited in quality and quantity. Two of the studies were reported as abstracts only so there was limited reporting of their methods and results. All the studies recruited a small number of people and were done in the US, limiting their relevance to the NHS care pathway. Only 1 study included adults, but it is not reported how many. The total study sample size was 7 so the number of adults is likely to be small so there is very limited evidence to support the effectiveness of using The Vest in adults.
Specialist commentators suggested that relevant outcomes to show the clinical effectiveness of The Vest would include the number of hospital admissions, antibiotic use, the number of chest infections and lung function. In people with cerebral palsy, 4 studies showed non-significant reductions in the number of hospital admissions after using The Vest. In 2 studies, there was reduced antibiotic use and a reduced number of chest infections (only 1 study showed a significant reduction in infections). Only 1 study reported oxygen saturation as an outcome. In people with amyotrophic lateral sclerosis, there was a significant reduction in the number of infections.
One specialist commentator suggested that The Vest needs to be used for 6 to 12 months before patient benefit can be clearly shown. In people with cerebral palsy, the duration of treatment was 12 months in 2 of the studies, and in 1 study it was at least 6 months. In the randomised controlled trial (Yuan et al. 2010), it was only 5 months. In the motor neurone disease study, the duration of treatment is not reported.
There is only 1 study which compared The Vest with chest wall physiotherapy; the other studies did not have a comparator. A large study comparing The Vest with chest wall percussion in adults and children with a range of complex neurological needs in a UK setting would give more robust evidence for its effectiveness.
Table 1 Summary of selected studies
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Study size, design and location |
Single-site, prospective pilot randomised controlled trial of 23 children with ND (n=14) and CP (n= 9) in the US. |
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Intervention and comparator(s) |
Intervention: HFCWO using The Vest (n=11; CP=4, ND=7). Comparator: standard chest physiotherapy (n=12; CP=5, ND=7). |
|
Key outcomes |
There was a trend in the chest physiotherapy group for more hospital admissions and antibiotics for pulmonary infection but there was no statistically significant difference between groups. There was a statistically significant difference in maximum saturation level of oxygen in haemoglobin after therapy in the HFCWO group (p=0.01) but no difference in the overnight saturation levels. The post-therapy apnoea-hypopnoea index was lower in the chest physiotherapy group (median 4.9; IQR 1.8, 77.65) compared to the HFCWO group (median 11.2; IQR 6.58, 39.0) but the difference was not statistically significant. There were no therapy-related adverse events in either group. |
|
Strengths and limitations |
28 children were enrolled but 5 withdrew after randomisation (2 with ND and 3 with CP). All had been randomised to HFCWO. This is a small pilot study that was not powered to show significance for any primary outcome. It is not reported which HFCWO device was used but the company has confirmed that it was The Vest. The study was partly funded by a grant from the company. The study included children with CP and children with ND but the study does not report the results separately; both subgroups have been combined. Specialist commentators advised that the comparator 'standard chest physiotherapy' as described in this study as '2 minutes in each of 6 positions' would not be considered standard UK chest physiotherapy practice. The mean treatment duration with The Vest was only 5 months. |
|
Study size, design and location |
A retrospective review of 13 children with CP in the US. |
|
Intervention and comparator(s) |
Intervention: HFCWO using The Vest. No comparator. |
|
Key outcomes |
There were fewer hospital admissions while using HFCWO compared to 1 year before using HFCWO (8 versus 5) and fewer emergency room visits (5 versus 1). Parents reported fewer respiratory illnesses and reduced antibiotic use after treatment. 9 parents reported improvement in their child's health and quality of life after treatment. |
|
Strengths and limitations |
This is a small retrospective study with no comparator. It is not reported which HFCWO device was used but the company has confirmed that it was The Vest. The study is reported as an abstract only with minimal reporting of the methods and results. Parent recall was used as a measure for respiratory illness, antibiotic use and missed school days, which could be at risk of recall bias. |
|
Study size, design and location |
A before-and-after study of 6 children with tracheostomy and muscle weakness related to CP or genetic syndromes in the US. |
|
Intervention and comparator(s) |
Intervention: HFCWO using The Vest. No comparator. |
|
Key outcomes |
There was a non-significant trend in the reduction of hospital days while using HFCWO compared to before using it (1.83±1.94 versus 0.50±0.80, p=0.082). |
|
Strengths and limitations |
The study is reported as a poster presentation only with minimal reporting of the methods and results. Only 6 children were included in the study. 4/6 children used an additional device to help them cough. |
|
Study size, design and location |
A before-and-after study of 12 people with quadriplegic CP at 2 nursing facilities in the US. |
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Intervention and comparator(s) |
Intervention: HFCWO using The Vest. No comparator. |
|
Key outcomes |
There was a significant reduction in pneumonia after treatment with HFCWO (18 versus 36, p=0.026) and fewer hospital admissions caused by pneumonia (3 versus 9) but this was not statistically significant (p=0.16). The added score of effective suctioning increased from 4,825 to 10,445 after treatment (p=0.008). |
|
Strengths and limitations |
The study included children and adults (age range 7 to 28 years) but it was a very small sample size (n=7) and a breakdown of the numbers of children and adults is not given. All had severe quadriplegic CP and were fed by gastrostomy tube so this was a severely unwell patient population. Patients from 2 different nursing facilities were included so there may be a difference in the treatment they had. Patients were also having manual chest physiotherapy and postural drainage programmes before and during treatment. The authors have reported there were differences in how these were delivered. |
|
Study size, design and location |
A before-and-after observational study of 36 people with MND in the US. |
|
Intervention and comparator(s) |
Intervention: HFCWO using The Vest. Comparator: no comparator. |
|
Key outcomes |
Before HFCWO using The Vest people with MND had 0.07±0.13 infections/month and after it reduced to 0.02±0.06 infections/ month (t test p=0.0638; Wilcoxon ranked test p=0.0415). |
|
Strengths and limitations |
The study is only available as an abstract so there is limited reporting of the methods and results. |
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Abbreviations: CP, cerebral palsy; HFCWO, high-frequency chest wall oscillation; IQR, interquartile range; MND, motor neurone disease; ND, neuromuscular disease. |
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