The technology

Smart Peak Flow (Smart Respiratory Products) is a digital peak flow meter and asthma tracking tool. It is designed for monitoring asthma. Smart Peak Flow measures peak expiratory flow (PEF). This is how fast a person can blow air out of their lungs after a deep breath and is a test of lung function. It measures airway obstruction and can show how well a person is breathing.

The technology includes the Smart Peak Flow meter and the associated Smart Asthma app, which can be downloaded from the Apple and Android app stores. The Smart Peak Flow meter has 2 parts: the peak flow meter turbine and a plastic mouthpiece. It needs a smartphone for use. The device is compatible with all smartphones using an operating system later than Android 5.0 or iOS 10. The mouthpiece is attached to the turbine and the device is plugged into the smartphone by the headphone jack port. A wireless Bluetooth adapter can be used for smartphones without a headphone jack port. Smart Peak Flow should not be connected to the smartphone while its battery is being charged. The device can be used when sitting straight or standing. It should be used in a well-lit area because the Smart Peak Flow meter needs light to go through a small window on top of the turbine to take the PEF reading. The mouthpiece and turbine should be cleaned regularly in line with the Smart Peak Flow user manual to make sure the device is functioning properly.

When first used, the app calculates a person's PEF baseline value from their known personal best PEF value or standardised scores. Future PEF readings are compared with this baseline. A person measures their PEF by taking a deep breath and blowing as hard and fast as possible into the Smart Peak Flow mouthpiece. The PEF value is then shown in the Smart Asthma app. This process is repeated twice, with the app saving the highest (best) of the 3 values. This is compared with the baseline and colour coded green, yellow, or red based on if breathing appears to be under control or if caution or medical assistance may be needed, respectively. Healthcare professionals' advice is needed to interpret Smart Peak Flow measurements and to determine what action should be taken when PEF values change.

The Smart Asthma app records PEF measurements as well as symptoms and inhaler use. It also automatically charts the recorded measurements. People can use the device at home and share information about their asthma with their healthcare professional by email. This can be used to monitor a person's asthma control and provide care when needed.

Innovations

The company claims that Smart Peak Flow is innovative in its remote monitoring of PEF and inhaler use. It measures PEF with the Smart Peak Flow meter and automatically records and charts this data in the Smart Asthma app. The technology also calculates the colour coded peak flow zones and provides an electronic asthma action plan based on the results.

Current care pathway

People aged 5 years and over who have been diagnosed with asthma are offered an asthma self-management programme. This includes a written personalised action plan and education to help self-manage their asthma. The asthma action plan should clearly outline how and when changes in treatment should happen. Asthma control is monitored at every asthma review using spirometry or peak flow variability testing. Validated questionnaires such as the Asthma Control Questionnaire or Asthma Control Test may be used to monitor asthma control in adults. Loss of asthma control may also be assessed by symptoms, particularly in children.

Peak flow readings play an important part in managing asthma. Because of this, people may be prescribed peak flow meters for self-monitoring at home. PEF should be recorded as the best of 3 readings. This value can then be compared with standardised charts or, more preferably, the person's previous measurements. People may be asked to manually record a diary or chart of PEF readings several times a day for a few weeks. This can be used to calculate PEF variability and to detect clinical deterioration.

Peak flow readings may help to understand triggers and guide use of reliever medication in line with a person's asthma action plan. If poor asthma control is found, an assessment can be done to understand why before treatment is changed. Support and education may be provided to improve adherence and inhaler use.

The following publications have been identified as relevant to this care pathway:

Population, setting and intended user

Smart Peak Flow is designed for people with asthma aged over 5 years. It is an alternative to mechanical peak flow meters. Peak flow meters may be offered to people with asthma in primary or secondary care. People can use Smart Peak Flow at home to monitor their asthma with the support of a healthcare professional. It is generally recommended for use twice a day; in the morning after waking and before going to bed. It should also be used when people are having symptoms of breathing problems. Smart Peak Flow should be used before an inhaler. Initial setup of the device and guidance for use should be provided by a healthcare professional. Adult supervision is needed when used by children and young people, and some disabled people.

Costs

Technology costs

The technology costs £9.87 per device (excluding VAT). The optional Bluetooth adapter costs £6 (excluding VAT) and the Smart Asthma app is free. The Smart Peak Flow device has a 2-year life expectancy.

Costs of standard care

Costs of mechanical peak flow meters range from £4.25 to £9.50 per device. Costs are taken from the NHS November 2021 Drug Tariff. Some mechanical peak flow meters are recommended to be replaced every 3 years.

Resource consequences

Smart Peak Flow is used in the NHS. The company claims that a recent survey of healthcare professionals showed consensus in the accuracy and timeliness of data collected by Smart Peak Flow. It also claims that more people are likely to use Smart Peak Flow as intended compared with traditional paper-based diaries and mechanical peak flow meters.

The company claims Smart Peak Flow had additional resource benefits during the COVID‑19 pandemic because healthcare professionals could use the detailed asthma diary in remote consultations. Results of an unpublished patient survey submitted by the company suggested that most users found the device quicker and easier to use and more convenient than paper-based diaries. There was no published evidence of its use in clinical practice.