Digital Inhalers for COPD, Asthma Are Tantalizing but More Research Is Needed, Review Says

Interest in the use of digital inhalers is growing, as they may provide real-world evidence about how patients monitor and treat their chronic obstructive pulmonary disease (COPD) and asthma at home, but additional questions need to be answered, according to a recent review.

While digital inhalers for chronic obstructive pulmonary disease (COPD) and asthma have been available for more than 20 years, they are only now becoming more widely used. In a recent review, researchers said many unanswered questions remain about their cost-effectiveness, acceptability, and effect on inhaler technique.

These devices—which may consist of a separate electronic sensor attached to an inhale, or an inhaler with the electronics embedded within it—have mostly been used in clinical trials.

Obstructive lung diseases affect about 15% of people worldwide and yet the inhaled medications that are needed to control these diseases require daily self-administration of inhaled therapies that require specific breathing techniques and good user coordination in order to optimize the intake of the drug. Adherence to these therapies, which could be complicated by a number of factors, is linked with worse outcomes in both COPD and asthma.

Electronic monitoring systems, sensors, and other methods of providing remote feedback to a provider comprise one way to help improve adherence and see what is happening in a home setting. In this recent review, the authors reviewed what is known about 3 inhalers and sensors currently on the market, as well as another device that is being studied in Ireland and the United Kingdom but is not currently sold.

The authors searched Ovid MEDLINE, EMBASE, CrossRef, and Google Scholar for English-language publications of randomized controlled trials, systematic reviews, and guidelines published from January 1, 2010, to April 1, 2021.

Studies were included if electronic monitoring devices and related mobile applications were used as part of an adherence intervention, with the primary outcome of improving medication use.

More than 20 clinical studies of digital inhalers demonstrated improvement in medication adherence, exacerbation risk, and patient outcomes, and echoed and expanded on past findings about patient inhaler use and behaviors, the authors said.

The review included the 4 devices that the authors said are the most commonly used. Two are available worldwide (Propeller Health and Adherium Hailie), 1 is available in the United States (Teva Digihaler), and 1 is available in Italy, Germany, Portugal, and the Netherlands (Amiko Respiro). Another, the INCA device, has been studied extensively in Ireland and the United Kingdom and so the authors included information about that one as well, even though it is not yet available.

The Propeller Health and Adherium Hailie are considered devices because they consist of a separate sensor that attaches to an existing inhaler; the Digihaler and the Respiro are considered drugs with digital capabilities. These latter 2 are considered “inspiratory-capable digital inhalers” and have the smallest share of the market. They have the ability to “guide proper inhalation effort by patients to improve technique and could possibly serve as a physiological measure of lung function,” the authors wrote, and might be seen as a “value-added function.”

When combined with information about symptoms, physiological measures, and environmental conditions, the devices would allow for more personal and individualized therapy decisions, they added. In addition, the data could provide greater context when clinicians are deciding whether to move patients who are not achieving control on inhaled medications to another level of potentially higher cost and complicated care, such as bronchial thermoplasty, biologics for asthma, and airway stents for COPD.

As an example, the authors cited findings from a study of adults with uncontrolled asthma who were considered eligible for biologics or bronchial thermoplasty; more than half were nonadherent with their digital controller inhalers.

“Ensuring correct diagnosis and evaluating adherence using digital inhalers are important steps to conduct prior to adding very expensive biologics to patients’ treatment regimens. Using digital inhalers to gather more information on patient medication-taking patterns may be the most impactful cost-effective use of these devices,” the authors noted.


Chan AHY, Pleasants RAP, Dhand R, et al. Digital inhalers for asthma or chronic obstructive pulmonary disease: a scientific perspective. Pulm Ther. 2021;7(2):345–376. doi:10.1007/s41030-021-00167-4