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
This briefing summarises 5 studies that were considered to provide the most relevant and highest quality evidence. All 5 studies focus on the use of Thora‑3Di in children and young people, and include of a total of 129 patients with asthma and 139 healthy volunteers. One prospective study is published in full and 4 further studies are published as abstracts; 4 of the studies originate from 1 clinical centre.
The studies show that Thora‑3Di can measure the inspiration to expiration flow ratio (IE50), which can be used to identify respiration affected by asthma symptoms. The studies also report differences in the variability of breathing patterns and changes in the thorax and abdomen measured using Thora‑3Di, which may also be significant in differentiating between obstructed asthmatic breathing and normal function.
Table 2 summarises the clinical evidence as well as its strengths and limitations.
Overall assessment of the evidence
The published evidence for Thora‑3Di is based on small studies mostly published as abstracts. These are generally relevant to the NHS pathway but are descriptive, comparing a variety of respiratory parameters measured using Thora‑3Di with conventional spirometry in healthy volunteers and patients with asthma, both before and after bronchodilator treatment. The studies also use the device to measure timing parameters and anatomical changes associated with breathing but there are no agreed thresholds for these against conditions diagnosed using spirometry. There are no studies or subgroup analyses specifically on younger children with asthma, in which Thora‑3Di may have significant advantages, but they are included in the patient groups. Larger, prospective studies would help to determine the Thora‑3Di breath parameters of most diagnostic utility for asthma.
Table 2 Summary of selected studies
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Study size, design and location |
Prospective, observational, case-control study. 71 children and young people (aged 7 to 16 years), UK. |
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Intervention and comparator(s) |
Thora‑3Di compared with abnormal spirometry and bronchodilator challenge test spirometry to measure FEV1 and IE50. |
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Key outcomes |
The asthma group showed a significant increase in spirometry-assessed mean FEV1 after administration of bronchodilator. Median IE50 was higher in children with asthma (before using a bronchodilator) compared with healthy children. After giving bronchodilators to the asthma group, median IE50 decreased from 1.53 to 1.45 (p=0.01). |
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Strengths and limitations |
This is a small observational pilot study. It indicates that some changes in breathing parameters measured by Thora‑3Di can be used to tell healthy children from those with asthma and the subsequent effect of treatment. The healthy controls did not have standard spirometry so a full comparison was not possible. It is unclear if the statistically significant changes noted represent clinically significant differences. The study was sponsored by the company. |
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Study size, design and location |
Prospective, observational, case-control study. 93 children (2 to 12 years), 39 with asthma, 54 healthy controls, UK. |
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Intervention and comparator(s) |
Thora‑3Di, no comparator. |
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Key outcomes |
Median IE50 was higher is the asthma group (1.47 compared with 1.41; p=0.002) but there was no change in response to bronchodilator treatment (1.47 vs 1.5; p=0.477). |
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Strengths and limitations |
This study was presented as an abstract with limited information. It shows that Thora‑3Di can take measurements in children aged 2 to 12 years and some of the respiratory parameters measured may be able to be used to identify asthma in children. The study was sponsored by the company. |
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Study size, design and location |
Prospective, observational study. 33 children (age not specified), UK. |
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Intervention and comparator(s) |
Thora‑3Di, no comparator. |
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Key outcomes |
Rib-cage versus abdominal contribution to breathing decreased significantly following bronchodilator intervention (46% to 42%, p=0.016). The respiratory rate, inspiratory time ratio and IE50 did not significantly change after bronchodilator treatment. |
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Strengths and limitations |
This study was presented as an abstract with limited information. It shows that Thora‑3Di can be used in children admitted to hospital with a diagnosis of asthma. The age of the group of children was not defined; this is the same group as that in Hmeidi 2016. The study was sponsored by the company. |
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Study size, design and location |
Prospective, observational study. 27 children with asthma (median age 7.9±3.36 years; 6 patients were preschool children), Italy. |
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Intervention and comparator(s) |
Thora‑3Di compared with abnormal spirometry and bronchodilator challenge test spirometry to measure FEV1 and IE50. |
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Key outcomes |
The children with well-controlled asthma had a lower FEV1 measured with SLP compared with spirometry (106.1 vs 69.7, p=0.0002). IE50, measured using SLP, was also lower in the well-controlled group, was 1.16 (0.99 to 1.54) compared with 1.40 in the spirometry group (1.25 to 1.72, p=0.026). The authors concluded that the IE50, from SLP measurements, could differentiate between children having an asthma exacerbation and those with well-controlled asthma, and this matched the FEV1 data from spirometry. |
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Strengths and limitations |
This study was presented as an abstract with limited information. It shows SLP can be used in children with a diagnosis of asthma. |
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Study size, design and location |
Prospective, observational study on 44 young people and children (aged 3 to 17 years) with asthma in the UK. Company sponsored. |
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Intervention and comparator(s) |
Thora‑3Di, no comparator. |
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Key outcomes |
Results of the tidal breathing parameters RR, Ti/Ttot, IE50 and RC2Tot were presented stratified by age groups, with demographic information on height and weight. |
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Strengths and limitations |
This study was presented as an abstract only with limited information. It shows Thora‑3Di can be used in healthy young people and children who do not have asthma and presents normative data categorised by age, height and weight. These are the same normal controls as those studied in Hmeidi et al. 2016. |
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Abbreviations: FEV1, forced expiratory volume in the first second; IE50, ratio of inspiratory to expiratory flow at 50% of tidal movement; RC2Tot, relative contribution of chest wall movement to total movement; RR, respiratory rate; SD, standard deviation; SLP, structured light plethysmography; TA, thoracoabdominal; Ti/Ttot, inspiratory time ratio; VT, tidal volume. |
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