Advice
The technology
The technology
Smart One (Medical International Research) is a spirometer that connects to a Bluetooth-enabled smartphone or tablet to monitor peak expiratory flow (PEF) and forced expiratory volume in 1 second (FEV1). PEF is the maximum speed of air as someone exhales as hard as possible after filling their lungs completely. FEV1 is the volume of air expelled during the first second of the same exhalation. Smart One connects to the smartphone or tablet through a Smart One app.
The technology includes the handheld Smart One device, the turbine sensor which is inserted into a round slot on Smart One, and a reusable plastic mouthpiece, both of which can be removed for cleaning. The mouthpiece must be disinfected after every use, and the turbine should be checked after each use and cleaned if it contains any dust or foreign bodies.
The Smart One app (available for any mobile operating system) includes an electronic diary for recording results and a message displayed on the screen to help improve test performance (for example, 'blow out fast'). When first opened, the app requests the user's date of birth, 'population origin' (ethnicity), weight, height and sex to calculate baseline PEF and FEV1 values, based on large epidemiological studies. If any of these personal details are not entered, the app issues a warning message.
To use Smart One, the user exhales into the mouthpiece. The turbine sensor measures exhalation in real time and transfers the results to the Smart One app. The app compares the measurements with the baseline PEF and FEV1 values, and displays numerical values as well as a 'traffic light' health indicator (green, yellow or red) to signify if the measurement is above or below the baseline. Alternatively, the app can store the user's 'personal best' value (based on the highest of 3 exhalations) and use it to calculate the traffic light health indicator.
The device is intended for use by 1 person only. If the organisation issuing the device transfers it to another user, the mouthpiece and turbine must be disinfected and the previous user's data must be erased from the memory. The new user must then input their baseline data into the app.
Unless the user chooses to send measurements to a healthcare professional (see below), measurements and user data are stored only on the smartphone. The manufacturer warns users that potential threats to data collected by the app include malware installation, interception of communications, or theft of the smartphone. These could affect the integrity or confidentiality of personal data. The manufacturer recommends reducing the risk to personal data on a smartphone by using antivirus software, using a password, and backing up data periodically.
The innovation
Smart One could enable people who need spirometry to record their PEF and FEV1 values in their own homes, allowing them to take these measurements when most needed (such as during an exacerbation of their symptoms). The app also allows the user to create and attach a PDF file to a standard email and send to their healthcare professional. The user can choose the time interval (from 1 day to 1 year) to be exported into the PDF.
Current NHS pathway
Spirometry is a test used to help diagnose and monitor lung conditions by measuring how much air a person can breathe out in 1 forced breath. For people who have already been diagnosed with a respiratory condition, spirometry may be done to check the severity of the condition or to monitor treatment response. Each spirometry measurement is repeated at least 3 times to get a reliable result, and the maximum reading is recorded (NHS Choices).
Recommendations for spirometry in people with respiratory conditions vary depending on their diagnoses. The NICE guideline on chronic obstructive pulmonary disease in over 16s states that spirometry should be done at diagnosis, and repeated to consider a second diagnosis if a person shows an exceptional response to treatment. FEV1 and forced vital capacity should be measured at least once a year in people with chronic obstructive pulmonary disease. The guideline also states that PEF or FEV1 should not be done daily to monitor recovery from an exacerbation, because the size of changes is small compared with the variability of the measurement.
For people with asthma, the British guideline on the management of asthma states that spirometry should be quality assured and done by people with adequate training. The guideline recommends lung function assessment by spirometry or PEF to monitor adults in primary care, and PEF aids in determining asthma severity. It also states that PEF is best used to provide an estimate of variability of airflow from multiple measurements made over at least 2 weeks. Increased variability may be evident from readings twice daily and serial peak flow records may demonstrate variability in symptomatic patients, but should be interpreted with caution and with regard to the clinical context. Measuring lung function in children under 5 years is difficult so spirometry is not recommended in this population.
The guideline recommends that self‑management be included in each patient's personalised asthma action plan. Self‑management action plans contain information on when and how to modify treatment in response to asthma symptoms and PEF measurements. Symptom‑based plans are generally preferable for children. The guideline states that the evidence of the clinical benefits of telemonitoring of asthma is mixed but is at least as good as traditionally delivered care, and states that telehealthcare may be considered as an option for supporting self‑management of asthma.
The Standards for the Clinical Care of Children and Adults with Cystic Fibrosis in the UK recommend regular monitoring of lung function with spirometry in children aged 5 to 6 years, and oxygen saturation measurements with pulse oximetry at every clinic visit for outpatients. The timing of clinic visits varies based on a person's needs, but routine appointments for a stable patient should be every 2 to months. Spirometry is recommended twice weekly for inpatients.
Smart One would be used in the current clinical pathway for people needing spirometry measurements as part of their self‑management plan. It would not be used to diagnose chronic obstructive pulmonary disease.
NICE is aware of 6 similar portable spirometer devices in development for use with smartphones.
Population, setting and intended user
Smart One is intended for use as a self‑monitoring tool by people with respiratory conditions. It could be used in any setting, including in the home, to measure PEF and FEV1.
Costs
Device costs
Smart One costs £99.95, excluding VAT. The manufacturer instructions recommend that it be used twice a day. Smart One and the mouthpiece are expected to have a lifespan of 10 years. Assuming that Smart One is purchased by the NHS and used continuously throughout the year, using a standard annuity calculation with a 3.5% discount rate, the cost per measurement would be £0.02. The manufacturer also provides an example of how quantity discounts may affect price: if 500 units are purchased together, they will cost £49.95 each (£0.01 per measurement). A suitable smartphone or tablet is needed to use Smart One.
Costs of standard care
Standard care is spirometry. Spirometers range in cost from approximately £300 to £3,000 depending on the complexity of the device (Barema, the Association for Anaesthetic and Respiratory Device Suppliers 2016, British Thoracic Society 2005). A UK cost-effectiveness analysis of treatments for chronic obstructive pulmonary disease (Hertel et al. 2012) provides a more comprehensive unit cost for an outpatient procedure of £49.98.
Resource consequences
The manufacturer stated that Smart One is new and currently used in very few NHS trusts. However, a small number of trusts use similar spirometers from the same manufacturer.
No practical difficulties have been identified in using or adopting the device component of Smart One, and no special training is needed. Batteries and other consumables need to be replaced and it is unclear whether the NHS would be responsible for these costs.
No published evidence on the resource consequences of adopting Smart One was found. A trial‑based UK economic evaluation (Ryan et al. 2012) compared conventional paper‑based monitoring with a phone app for recording and transmitting peak flow readings and triggering automatic contact by a nurse. This evaluation was not directly related to Smart One, but it found no statistically significant difference in asthma control between groups and a slight increase in costs associated with this kind of app‑based monitoring. The cost increase was because of the expense of the app in addition to usual health service costs, but the authors noted that this difference may decrease in clinical practice where economies of scale could reduce the cost per patient.