Smart One for measuring lung function

Level of innovation

The specialist commentators considered Smart One to be a minor innovation to existing spirometry technology. Although its ability to record measurements on a smartphone through Bluetooth is novel, there are other similar devices in development.

Spirometry is usually done by a healthcare professional and requires special training. One specialist felt that spirometry should only be done by healthcare professionals. Another specialist noted that people can use peak flow meters with little training but forced expiratory volume in 1 second (FEV1) is a more difficult measurement to take and some patients find it extremely difficult.

Potential patient impact

Smart One may improve self‑monitoring and engage people who dislike manual recording of peak flows, but it is not clear whether the device would improve outcomes. The long-term adherence, psychological benefits (for example, feeling reassured) and potential adverse effects are all unclear. The benefits of using Smart One may vary based on the patient population; for example, people with chronic obstructive pulmonary disease might have only minor benefits whereas those with cystic fibrosis or lung transplants have the potential for greater benefits. Peak expiratory flow (PEF) monitoring may be useful in patients with asthma, because there is good evidence for home monitoring and improved health outcomes in these people. All these uncertainties require a prospective, controlled investigation in differing patient populations.

The device may be useful in a clinic facility to monitor and save the results of FEV1 and PEF in patient records, but this is outside the manufacturer's recommendations for use.

Training and familiarity with smartphone apps may be a barrier for some patients, but all commentators felt that the main barrier for using Smart One at a community level would be the ability of patients to carry out the spirometry measurements. There are likely to be a small number of highly trained patients who can do spirometry independently, such as people with cystic fibrosis. However, 1 commentator highlighted that it might be especially difficult for many groups of people with chronic obstructive pulmonary disease.

Potential system impact

Similar to the potential impact on patients, the potential system impact is unclear because of the lack of evidence. Using Smart One could lead to an increased need for healthcare professionals to download and review recordings, involving increased nurse or GP time. Nurses and GPs would need to be trained in its use and additional time would be needed to train patients.

Smart One may improve self‑management in a select group of patients and therefore reduce healthcare resource use (such as emergency department attendances), but there is no evidence for this. One specialist stated that it would not lead to cost savings, because most patients do not use their inhalers as prescribed and so would be unlikely to test lung function twice daily. The cost per device is also greater than a Wright peak flow meter, which is generally recommended for home monitoring. Smart One is less costly than existing spirometers, but its functionality is more comparable to a device that monitors FEV1 alone, which is far less costly.

General comments

One specialist commentator stated that peak flow rates and spirometry require different techniques and it may be time consuming, and potentially confusing, for patients. The specialist stated that it is important for the user to have visual feedback as to whether the correct technique is being done.

Peak flow rate is often used to monitor asthma and to support an asthma action plan (which is also based on symptoms). There are no data as to whether regular spirometry leads to better outcomes. In addition, self‑management plans for chronic obstructive pulmonary disease are symptom‑based and not reliant on spirometry values. One specialist stated that it is unclear how FEV1 thresholds could be individualised using an algorithm for all patients, because there are no FEV1 thresholds in clinical use as there are for PEF.

New innovations developed with patients are important to encourage self‑management, and the use of an electronic device to record peak flow rates will have a role in monitoring asthma control. The role of regular FEV1 measurement is far less clear, more difficult to implement because of the difficulties with technique, and not as clinically useful.

Another specialist agreed that FEV1 measurements may be difficult for patients compared with PEF, but that FEV1 is a more sensitive and robust measure of airflow obstruction. They explained that similar applications have had the potential to benefit patients in the past, but they have not yet been adopted because of multiple technical issues, even in highly selected patient groups. Generally, personalised asthma management plans are rarely adequate in practice. Non-adherence is a large problem for people managing asthma and introducing Smart One will not necessarily improve self‑management.

PEF and FEV1 using this device are recorded from the same exhalation. However, the specialist stated that the gold-standard PEF (by meter or gauge) is recorded from a very rapid exhalation (different from the FEV1 manoeuvre) and this is just one way in which the PEF by meter or gauge is likely to numerically differ from that recorded by this device.

More data are needed to validate and justify Smart One's clinical use, preferably from large-scale controlled trials as well as well-documented real-world experiences from patients with relevant conditions.