Clinical and technical evidence

A literature search was carried out for this briefing in accordance with the published 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

No publicly available evidence was found on the use of Smart One.

Instead, this briefing summarises 3 studies that used similar devices from the same manufacturer, including 496 patients. Two of the studies used Spirotel (a portable touchscreen spirometer and oximeter tool for home care and telemedicine; Ezzahir et al. 2005, Fonseca et al. 2005) and 1 used Spirobank (a portable spirometer and oximeter with an option to connect with an iPad, intended for clinicians; Liistro et al. 2006). According to the manufacturer, the turbine in Smart One used to measure forced expiratory volume in 1 second (FEV1) and peak expiratory flow (PEF) is the same as that in all its spirometers.

Table 1 summarises the clinical evidence for these 2 spirometers as well as its strengths and limitations.

Overall assessment of the evidence

The current evidence shows that the turbine technology used in the manufacturer's spirometers has good reproducibility for measuring PEF and FEV1 (Ezzahir et al. 2005, Fonseca et al. 2005, Liistro et al. 2006). However, there is conflicting evidence about the limits of agreement for FEV1 reported in 1 study (Liistro et al. 2006), showing that this was not acceptable based on the short-term coefficient of variability values.

As with Smart One, there is no published evidence on the effectiveness of any of these devices. App technology is a rapidly evolving area and the amount of evidence for medical device apps varies, although there is some evidence on smartphone self‑management apps for asthma (Marcano et al. 2013).

Useful evidence in this area would include data on the usability of the app and device, clinical outcomes (for example, if the device reduces emergency department or GP visits), how the app affects behaviour, and long-term cost savings.

Table 1 Summary of evidence

Ezzahir et al. (2005)

Study size, design and location

59 children at their routine lung function tests at a hospital (with asthma, chronic cough, or sickle-cell disease), prospective comparative study, France.

Intervention and comparator(s)

Spirotel compared with a laboratory spirometer (Jeager PFT).

Key outcomes

At least 2 acceptable and intra-device reproducible curves were obtained in 88% of the laboratory and 76% of the portable spirometers. Forced expiratory flow between 25% and 75% of forced vital capacity (FVC), and forced expiratory flow at 75% of FVC were similar between spirometers, both at baseline and post-administration of a bronchodilator.

Strengths and limitations

The 2 spirometers were tested in a random order at baseline and in reverse order post-bronchodilator.

The study did not evaluate the recording and transmitting functions of Spirotel. No sample size calculation was reported and thus it is unclear if the sample size was adequate to assess outcomes.

Fonseca et al. (2005)

Study size, design and location

38 adults with asthma used each device and the reference instrument, randomised agreement study, Portugal.

Intervention and comparator(s)

Electronic monitoring devices: Spirotel, PiKo-1, and Mini-Wright peak-flow meter.

Reference: Vitalograph (pneumotachograph).

Key outcomes

Good intra-device reproducibility and agreement between the pneumotachograph and both electronic monitoring devices.

Strengths and limitations

The study included spirometers with an established flow measurement (pneumotachograph) as the reference instrument. The order in which devices were used was randomised.

The study did not fully evaluate the measurement capabilities of Spirotel (forced expiratory flow, for example) and did not evaluate the recording and transmitting functions of the devices. There was no sample size calculation reported and thus it is unclear whether the sample size was adequate to assess outcomes.

Liistro et al. (2006)

Study size, design and location

399 people (300 with chronic obstructive pulmonary disease, 9 expert technicians and 90 healthy patients), multicentre comparative study at 3 hospitals, Belgium.

Intervention and comparator(s)

Office spirometers: Spirobank, Datospir 120, Datospir 70, EasyOne, Microloop, OneFlow, Pneumotrac, Simplicity, SpiroPro, SpiroStar.

Standard spirometers: Vmax 20C and Morgan TLC.

Key outcomes

User-friendliness of the devices was good overall. Precision of forced expiratory volume in 1 second (FEV1) was comparable between the standard and the 10 office spirometers in most of the devices. There was no significant difference between centres in absolute values and intra-device reproducibility. The Spirobank limits of precision were acceptable, however the limits of agreement for FVC and FEV1 were not acceptable based on the short-term coefficient of variability values.

Strengths and limitations

Tests were done in a random order to avoid a learning effect. People with various degrees of chronic obstructive pulmonary disease were included.

The study assessed office spirometers only, not portable spirometers for home use. Usability was based on a questionnaire to 3 general practitioners.

Recent and ongoing studies

According to the manufacturer, studies comparing Smart One with other means of self‑monitoring PEF and FEV1 in the community are in progress, but no publicly available data are available.