Abstract
Inhaled therapies remain the cornerstone in managing chronic airway diseases, offering direct treatment delivery to the lungs with minimal systemic adverse effects. With advancements in respiratory care, digital inhalers have emerged as a transformative innovation. Their functions extend beyond delivering inhaled medication, providing deeper insights into patients’ medication use behaviour and intervening through complementary platform features and integrated data analytics. However, despite being available for over two decades, the widespread adoption of digital inhaler platforms remains limited due to uncertainties regarding their cost-effectiveness, feasibility in real-world settings, and concerns regarding sustainability. Identifying patient groups that could benefit most from these technologies and designing strategies for effective deployment across diverse healthcare contexts is important. To achieve this, bridging the gap between innovation and accessibility is required so that digital inhaler platforms evolve into inclusive, patient-centred tools rather than niche technologies. This narrative review provides a summary of the evolution and current landscape of digital inhaler technology, its impact on clinical outcomes in chronic airway disease, and key challenges that stakeholders should address for the successful integration of these tools into respiratory care. We also propose key components of a patient-centred digital inhaler adherence support model that prioritises accessibility and efficacy.
Introduction
Optimising adherence to inhaled therapy remains a significant challenge,1,2 with poor adherence consistently associated with increased morbidity and mortality in chronic airways disease, asthma and chronic obstructive airway disease (COPD).3–5 While newer therapies such as monoclonal antibodies3,4 offer effective treatment options, they are costly (nearly $300,000 per quality-adjusted life-year 6 ) and cannot replace inhaled therapies. Indeed, nearly 65% of patients with difficult-to-control severe asthma could potentially avoid biologics if their inhalers were used effectively. 7 Among severe asthma patients who are receiving anti-interleukin (IL)-5 therapies, the subgroup with poor adherence to inhaled corticosteroids (ICS) experienced a higher exacerbation frequency and less tendency to stop maintenance oral corticosteroids compared to those who are adherent. 8 In the recently published SHAMAL study, switching from regular to as-required anti-inflammatory reliever (AIR) ICS regimes led to a lung function decline among patients receiving anti-IL5R. 9 Thus, National Institute for Health and Care Excellence (NICE) guidelines and the Global Initiative for Chronic Obstructive Lung Disease (GOLD) report recommend assessment of adherence to the prescribed inhaled regimes before considering advanced therapies.10,11
Complexities in adherence assessment and digital solutions
Inhaler adherence is a multifactorial behavioural pattern that varies within and among patients over time across treatments.12,13 It constitutes three important elements: (1) initiation (i.e., commencement of prescribed inhaled therapy), (2) implementation (i.e., taking treatment precisely as prescribed) and (3) persistence (i.e., adherence over time). 12 Intentional non-adherence often stems from individual beliefs regarding the treatment necessity and concerns, 14 while unintentional non-adherence may arise from the technical challenges of inhaler use13,15 forgetting to take medication regularly. The recent GOLD 2025 report highlighted influencing factors for medication adherence, including co-morbidities, mental and socio-economic status, and ageing.11,16
Addressing adherence requires more than sporadic interactions between healthcare professionals (HCPs) and patients, especially when not all forms of non-adherence are easily reversible. Timely assessment is crucial to differentiate between treatable and non-treatable non-adherence forms. Otherwise, strict adherence thresholds for advanced therapies may compromise clinical outcomes (e.g., in the UK National Health Service (NHS), satisfactory adherence to routine therapies is essential to get access to biologics prescription in asthma).17,18
Not every adherence monitoring method is ideal. Self-report measures have recall biases whereas canister weighing and dose counting can be confounded with dose dumping. The medicine prescription ratio (MPR) often oversimplifies adherence patterns, categorising them into static underuse or overuse groups. Besides, collecting prescriptions does not guarantee the implementation of treatment regimens. Overall, conventional assessment methods often fail to capture the daily adherence behaviour in real life. This is important, especially with the emerging role of patient-led ICS dosing regimens in chronic airway disease (e.g., maintenance-and-reliever therapy (MART) and AIR regimens), where ICS and long-acting beta agonists are taken as required.
On the other hand, the technique of inhaler device handling also plays a crucial role in determining the treatment efficacy. Currently, nearly 200 aerosolised medications are available for managing chronic airway diseases, delivered via three primary device types: pressurised metered-dose inhalers (pMDIs), dry powder inhalers (DPIs), and soft mist inhalers (SMIs). Each device requires specific handling techniques: slow and coordinated inhalation for pMDIs, rapid and forceful inhalation for DPIs, and slow but deep inhalation for SMIs.19,20 Fewer than 20% of patients can use their inhalers correctly, with almost 90% demonstrating at least two critical technique errors if left unaddressed.21–23 In vitro studies demonstrated that subtle errors, such as 0.5-second delays between actuation (release of medication from the inhaler) and inhalation (breathing in the medication), can substantially reduce the amount of drug deposited in the lungs. 24 These errors are often imperceptible to patients, yet they can compromise treatment efficacy. This highlights a significant gap in adherence intervention as nearly a third of patients have never received any inhaler training. 23 Alarmingly, as low as 15% of HCPs can adequately evaluate inhaler techniques.23,25 These shortcomings are particularly concerning for socioeconomically disadvantaged individuals, who face higher risks of adverse outcomes.26,27
Emerging needs for digital solutions in adherence support
The future of healthcare is poised for innovations driven by artificial intelligence (AI), virtual healthcare, wearable devices, and large language models. Against the backdrop of the COVID-19 pandemic, the adoption of digital innovations or telemedicine (i.e., provision of clinical care using information and communication technologies 28 ) in the healthcare sector became the ‘new normal’. Nearly 78% of WHO/European Member States are using telemedicine and 90% of global health services use social media platforms and electronic health records.29,30 In the UK NHS service, 28 million more people had used NHS websites or digital apps between the year 2021 and 2023. 31
Overview of evidence on digital inhaler devices that are available in the market and stratified according to the sensor type.
pMDIs: pressurised metered-dose inhalers; DPIs: dry powder inhalers; SMIs: soft mist inhalers; PIFR: peak inspiratory flow rate; PEFR: peak expiratory flow rate; FEV1: forced expiratory volume in 1 s.
Devices used solely for inhaler training (e.g., T-Haler, 2Tone Inhaler Trainer, AIM (Aerosol Inhalation Monitor), and Flo-Tone CR (controlled resistance) 112 are excluded from this table.
aEMA approval securing CE marking.
bFDA approved.
Evolution and current landscape of digital inhaler technology
Digital inhalers feature electronic sensing systems that constitute sensors, microcontroller units for processing data, and communication modules. Various types of sensors are employed to monitor inhaler use. Pressure sensors are most commonly used, detecting inhaler actuations and measuring inhalation effort, while acoustic sensors capture the sound of inhalation to assess technique and identify misuse. Environmental sensors monitor temperature, humidity, and air quality, further enhancing device functionality.
Digital inhalers fall into two main categories: integrated devices 35 with electronic sensing systems built within inhalers, and add-on devices that attach to existing inhalers for smart functionalities. These devices are often powered by non-rechargeable lithium coin cells or polymer batteries that support rechargeability via micro-USB or wireless charging. Add-on devices usually have a service life of around 12–24 months, whereas integrated devices face limitations as their battery functionality is tied to the lifespan of the inhaler, up to 13 months. 36 Many digital inhalers feature optional functionalities, such as LED indicators to track dose consumption, battery status and Bluetooth connectivity for data syncing with apps or healthcare systems.
Early development and milestones
The evolution of digital inhaler technology began with ChronologTM37,38 (1982), an electronic plastic holder for pMDI canisters, developed by Forefront Engineering Corporation. It was the first regulatory-approved device, capable of recording up to 4000 inhaler acutations.37,38 Research at the time informed that conventional prescription refill records and canister weighing methods overestimated adherence by at least 30% when compared against EIM using ChronologTM.37,38 Progress accelerated with add-on devices like Doser 39 in the 1990s, which stored 30 days of inhaler usage data but lacked data transfer capability to computers. Subsequent innovations followed: Smart Mist®)35,40 (Aradigm Corporation) and MDILog™35,40 (Westmed Technologies Ltd) devices that incorporated microprocessors to log inhalations, enabling clinicians to review the data retrospectively. Smart Mist®35,40 introduced the breath-actuated mechanism, releasing medication only with an adequate inspiratory flow rate and or volume. Meanwhile, MDILog™35,40 added wireless connectivity with users’ computers, enhancing research applications. By 2006, SmartinhalerTM41 (now Hailie® by Adherium Ltd) integrated Bluetooth technology for real-time adherence tracking by transmitting data directly to healthcare providers. The device also marked a step forward via features like audio-visual reminders and LED indicators for inhaler usage.
Modern digital inhaler technology
In 2014, Propeller Health®42,43 (Propeller Health Ltd) upscaled the landscape of EIM via its add-on sensors, featuring global positioning systems (GPS) and enhanced app functionalities. This allowed geospatial tracking of adherence and exacerbation triggers, providing actionable insights for patients and clinicians. Soon after, FindAir ONE 44 (FindAir Ltd) advanced these features by integrating information on pollen levels and air quality. In parallel, INCATM34,45 (Vitalograph Ltd) introduced acoustic sensing technology that utilises AI (Artificial Intelligence) algorithms to analyse inhalation profiles. This approach uncovered the significance of metrics like peak inspiratory flow rate (PIFR) to differentiate between attempted and correctly executed inhaler usage.34,46 In asthma, the use of INCATM followed by fractional exhaled nitric oxide (FeNO) suppression helped identify patient groups who had non-intentional non-adherence due to poor technique errors and otherwise identified as having steroid-resistant airway disease. 7 Although not commercially available, INCATM has significantly contributed to research on inhaler adherence.
Later, inspiratory capable devices using pressure sensors, such as CapMedic™ 24 (Cognita labs Ltd), Respiro® 47 (Amiko Ltd), and Smart Aerochamber®48 (Trudell Medical International Ltd) offered more precise inhalation parameters compared to traditional acoustic methods, which could be affected by external noises. 21 CapMedicTM technologies were reported to identify 40%–60% more of these errors compared to visual assessments by trained professionals. 24 Further advancing the field, integrated devices such as Teva Ltd’s Digihaler® 49 and Intelligent Control Inhaler (ICI) 50 (3M Drug Delivery Systems) assessed temporal adherence, inhalation efforts, and lung function, and provided real-time feedback on technique during the inhalation process. While Teva Ltd has announced the discontinuation of its Digihaler® products, ICI remains among the few commercially available integrated devices (See Table 1).
Evidence examining the impact of digital inhaler use on clinical outcomes
Summarised clinical outcomes from clinical studies using digital inhalers.
*Positive outcome but did not reach a statistical significance or a selective sub-group.
A key framework to consider when assessing or intervening inhaler adherence is the Perceptions and Practicalities (PAPA) framework proposed by Rob Horne et al.
13
It emphasises practical factors (e.g., inhaler technique, treatment-taking habit formation) and perceptual factors (e.g., patient beliefs, motivations) in tackling inhaler use behaviour. Through the lens of the PAPA framework, interventions using digital inhalers can be categorised into three distinct groups: 1. Interventions addressing practical and perceptual factors: These interventions employed automated app-based inhaler reminders or generic web-based content. 2. Personalised interventions addressing practical or perceptual factors: These involved tailored strategies, such as individual consultations regarding inhaler technique or adherence rate by healthcare practitioners (HCPs) using real-time data from digital inhalers. 3. Personalised interventions addressing both practical and perceptual factors: The most comprehensive approach, combining feedback and reminders from digital platforms with tailored consultations by HCPs.
Herein, we categorised adherence interventions using digital inhalers as follows;
Interventions addressing either practical and perceptual factors
Digital inhaler studies primarily targeted practical aspects of inhaler use, particularly establishing regular inhaler-taking habits. Non-personalised scheduled audio-visual (AV) reminders, SMS alerts, and app-based feedback on usage trends were commonly used.42,56,57 In randomised controlled trials, control groups typically receive passive electronic inhaler adherence monitoring (EIM), with the inhaler reminder function disabled. These approaches consistently improved inhaler adherence across diverse age groups. Charles et al. 56 reported a mean (SD) adherence rate (AR) of 88% (16) in the intervention group compared to 66% (27) in the control group, while Chan et al. 58 found a median AR difference of 54%. Both studies included adolescents and adults with asthma, employing AV reminders in the intervention arm with passive EIM in the control group. Vasbinder et al. 57 demonstrated a mean improvement in AR by 12% (95% CI: 7%–18%) using SMS reminders in the paediatric asthma group. In Sykes et al., 42 nearly half of severe asthma patients who were eligible for biologic therapies with suboptimal adherence remained stable on conventional inhaled therapy after 12 months of digital inhaler-based interventions. Nonetheless, clinical improvements such as lung function, asthma control, and exacerbation rates were inconsistent across studies. A few studies addressed perceptual barriers by combining AV reminders with generic web-based contents57,59 but benefits were limited to adherence boosts only.
Personalised interventions addressing practical or perceptual factors
Personalised adherence interventions combined digital inhaler features with healthcare practitioner (HCP)-led consultations. In most cases, app-generated alerts for inhaler overuse or underuse prompted HCPs to contact patients for adherence reinforcement. However, the resulting change in health-related quality of life (HRQoL), lung function, and healthcare utilisation remained statistically insignificant across most studies.43,60,61 Besides, adherence often declined over time. Alshabani et al. 43 explicitly reported a decrease in mean AR from 56% to 30% over 280 days among patients with COPD using digital inhaler platforms, with a weekly AR drop of 0.46%. This highlights that while immediate improvement is feasible using digital solutions, sustaining long-term adherence may require continued engagement.
A few studies have intervened in the inhalation technique using the biofeedback approach, where HCPs provided coaching on inhaler technique based on observed errors detected by digital inhalers. In Dierick et al., 62 biofeedback intervention using smart spacers reduced technique errors by 26% while errors increased by 15% in the control group. Sulaiman et al. 63 found that INCATM-derived biofeedback improved adherence over 90 days compared to face-to-face coaching, although technique errors were similar between groups. For patients with COPD, evidence remains limited. The meta-analysis by the Leicester COPD group including 1432 COPD patients found that HCP-led digital interventions improved mean AR by 18% (95% CI: 9%–27%) compared to passive EIM, with a possible reduction in healthcare utilisation but minimal impact on HRQoL or exacerbation rates. 55
Personalised digital interventions addressing both practical and perceptual factors
A subset of studies implemented personalised interventions addressing both practical and perceptual barriers. These strategies typically combined digital AV reminders with HCP-led structured education and motivational counselling, often guided by frameworks such as the Information-Motivation-Behavioural model.41,64–67 Interventions were commonly delivered by pharmacists, primary care physicians or dedicated study staff. Unsurprisingly, a consistent pattern of increased inhaler adherence resulted following intervention. Across 10 studies in asthma or COPD, seven reported improvements in HRQoL, and six documented reductions in lung function decline and or exacerbation frequency (See Table 2 and the Supplemental table).
Burgess et al. 68 found a mean AR of 79% versus 58% in children receiving app-based reminders and personalised adherence support compared to the control group, along with greater FEV1 improvement. In Weinstein et al., 67 mean adherence in the intervention group was 81%, with a greater improvement in mean ACQ score difference than control (0.75 vs. 0.19). Mosanim et al. 64 observed a 38.2% reduction in reliever use and a higher (though non-significant) odds of improved asthma control compared to the control. O’Dwyer et al. 69 used the biofeedback approach alongside the behavioural counselling. As a result, a higher adherence compared to traditional in-person technique coaching or control groups, with a reduction in St George Respiratory Questionnaire scores by −6.1 (p = 0.04) over 6 months.
In the context of exacerbation outcomes, Gregoriano et al. 70 reported a 40% lower risk of exacerbations among patients receiving app-based reminders and HCP-led counselling compared to controls (RR 0.60, 95% CI: 0.4–1.0). In the prospective study by Lin et al., 71 EIM with video consultations by asthma specialists and psychologists led to fewer asthma-related emergency department visits, improved asthma control, and reduced school absences among children with severe asthma. Foster et al., 65 in particular, compared different clusters of digital adherence interventions in asthma: inhaler reminders with feedback and/or personalised discussions against the control group receiving written action plans. While all groups demonstrated improved asthma control, those receiving scheduled reminders experienced greater reductions in exacerbations and adherence gains. Overall, digital inhaler-based interventions generally improve inhaler adherence by supporting habit formation. Regardless of personalisation, interventions targeting only the practical domain showed limited and inconsistent effects on clinical outcomes beyond adherence gains. In contrast, multi-faceted individualised interventions that combine habit-building and behavioural modification supports appear to achieve broader clinical benefits. Future studies should compare different digital intervention packages with varying intensities of technology support across diverse patient demographics.
Advanced data analytics and use of digital biomarkers
There is a growing use of predictive analytics and machine learning to analyse real-time data from digital platforms for detecting imminent exacerbations.36,49,72,73 The FDA defines such data, gathered through digital health technologies that reflect biological processes, as digital biomarkers. 74
Studies have demonstrated that electronically recorded reliever usage could predict exacerbations and mortality.75–77 Alshabani et al. 43 found that high reliever use (≥1.64 times above the average) had 28% sensitivity and 99% specificity for predicting COPD exacerbations within a week. By incorporating additional factors, such as daily inhaler usage, and inhalation profile (i.e., peak inspiratory flow rate (PIFR), inhalation volume and duration, and time to PIF), AI algorithms from inspiratory-capable albuterol Digihaler® 78 can forecast asthma exacerbations, with an area under the curve of receiver operator characteristics (AU-ROC) values between 0.75 and 0.83. While increased reliever consumption is the strongest predictor of exacerbation in asthma, change in PIFR seems to be the most critical for COPD.36,49,72,73 On the other hand, a quick recovery of PIFR was observed in asthma while the COPD group took more than 14 days post-exacerbation to recover, likely due to more severe airflow limitation and comorbidities. 72
Beyond patient-specific inhaler use patterns, environmental factors have also been identified as important predictors of exacerbations. Data from the Propeller Health platform revealed that a 1 μg/m3 increase in weekly PM2.5 exposure correlated with a 0.82% rise in weekly reliever use. 79 This highlights how machine learning could facilitate personalised management by accounting for patient-specific disease severity, environmental triggers and inhalation characteristics.
Challenges for stakeholders to integrate digital inhalers into healthcare systems
Despite strong evidence supporting digital inhalers improving adherence, their widespread adoption hinges on several additional factors.
Regulatory approval process and barriers to market entry
Manufacturers of digital inhalers face stringent regulatory requirements before entering the market (e.g., Food and Drug Administration (FDA) 80 in the U.S., Medical Device Regulation (MDR) bearing CE marking in the European Union, 81 the Medical Device Regulation (MDR) bearing CE marking in the European Union in the UK. 82 Integrated devices, classified as digital-drug combinations, undergo more rigorous scrutiny, requiring New Drug Applications or Premarket Approvals. This involves extensive clinical trials, in vitro tests and user surveys to demonstrate the safety and efficacy of both medicinal products and technology. 83 In contrast, add-on devices generally follow a simpler FDA 510(k) notification or CE marking process, primarily needing to demonstrate the performance equivalence to existing products. 80 However, even minor engineering changes can impact cost and approval timelines. For instance, if a critical electronic component is discontinued by the industry, manufacturers may face significant redesign and recertification challenges. Furthermore, regulatory and data protection frameworks are still evolving in many regions, which further complicates the approval process. 35
Data interoperability and privacy concerns
The use of real-time data involves integrating vast amounts of sensor-based information with electronic health records (EHRs). It requires strong governance, including robust IT infrastructure and strict adherence to privacy regulations such as GDPR and Data Protection Impact Assessment. A key challenge lies in ensuring that digital platforms meet interoperability standards such as Fast Healthcare Interoperability Resources (FHIR) and Health Level Seven (HL7) for integration into clinical workflow. However, the med-tech industry often lacks standard interoperability due to the proprietary nature of healthcare systems, complicating data integration and creating variations in data formats. Privacy concerns regarding the collection, storage, and sharing of sensitive health information further demand vigilant management.
Acceptance and trust among patients and healthcare providers
Early studies by Simpson and colleagues 84 revealed a great enthusiasm among patients for mHealth, the use of technologies and electronic devices for healthcare,85,86 but data security concerns were prominent. Only 12% felt comfortable accepting treatment decisions based on mHealth data alone, rising to 41% when clinicians endorsed the changes, reflecting the importance of HCP involvement.
A recent survey by the Asthma and Lung UK 87 involving over 3000 respondents, indicated the evolving attitudes toward digital health tools. The majority were comfortable sharing their health data for healthcare and data analytics. Younger individuals (aged 18–29 years) were more supportive compared to those aged 70 and above. The systematic review of patients’ feedback on digital inhaler platforms conducted by our study group also mirrored similar feedback. 55 Over 90% of patients and researchers considered digital inhaler platforms easy to use and helpful. However, 14% (95% CI: 5%–23%) of research participants experienced issues of lost/malfunctioning study devices or apps, underscoring the need for careful design to address data privacy and technical reliability. 55 Besides, the duration of digital inhaler-based interventions ranges from less than a month to 2 years in asthma and COPD.55,88 While short-term use is generally well accepted by patients, evidence on the long-term engagement and impact remains limited. In studies using conventional care, the average frequency of intervention, especially targeting inhaler technique, is three times per year. 89 Similarly, digital intervention programmes with repeated engagements resulted in meaningful success. 55 This comes at the risk of fatigue from digital tasks among participants. Future research should explore the optimal and acceptable frequency of digital intervention among patients, the longevity of impact and identify strategies to sustain engagement.
Environmental impact and sustainability of digital inhalers
Before implementing digital inhalers in health services, their environmental impact must be considered. Research examining the sustainability of digital inhalers is emerging. Digital inhalers may attach to either pMDI or DPI devices, but if attached to pMDIs, their environmental footprint rises. Hydrofluorocarbon propellants from pMDI account for 3%-4% of NHS carbon emissions in the UK.90,91 Digital inhalers contain a mixture of recyclable (plastics, circuitry, metal and batteries) and non-recyclable components (some metal and residual medicine). Murphy et al. highlighted poor inhaler waste disposal practices among patients with 90% using domestic streams. 90 While some pharmaceutical companies90,92,93 support regional inhaler disposal initiatives, dedicated recycling schemes remain limited in scale and have not achieved a country-wide impact yet. Besides, electronic waste created by digital inhalers poses another challenge. While individual inhalers consume minimal power, the supporting cloud infrastructure significantly increases cumulative energy demands. Nonetheless, the potential of digital inhalers to improve patient adherence and health outcomes may offset some of these impacts.
Assessment of cost versus benefits
Adopting digital inhalers in healthcare settings entails several upfront costs for purchasing devices, platform set-up and staff training. A digital inhaler can cost between $50 and $300,94–96 though commercial insurance or bulk purchasing can reduce costs to as little as $20 per prescription. 95 Non-rechargeable models generally last at least a year, while rechargeable ones need to be powered up every 4–6 weeks.48,97 Additional charges may be incurred for HCP for software access and platform maintenance. Critics have questioned whether the investment is justified, given the limited number of economic modelling studies. Furthermore, the time and staffing required to initiate patients on digital inhaler platforms may present additional barriers, particularly within resource-constrained primary care settings.
A comprehensive evaluation of cost-effectiveness is complex, factoring in patient demographics, reductions in hospitalisations, savings from decreased rescue medication usage, primary care visits, and daily symptom control over the long term. Cost-effectiveness differs widely based on the outcomes measured and unique factors within each healthcare setting. For instance, studies based in the UK have shown annual savings of 96 to 845 GBPs per COPD patient.96,98,99 In the US, reimbursement mechanisms exist for remote monitoring, but coverage is not universal across insurers. 96 Thus, direct comparison across systems is challenging. As the digital inhaler market grows, increased competition may further reduce prices and enhance cost efficiency.
A systematic review on m-Health interventions in chronic airway diseases also highlighted that studies involving real-time monitoring or teleconsultations predominantly showed favourable economic outcomes. 100 Van Boven et al.34,99 conducted a cost-benefit analysis of digital inhaler interventions for COPD (n = 226) from an Irish healthcare payer perspective. Patient groups with good inhaler techniques but using their inhalers irregularly (36% of cohort) showed the highest savings with €845/annum/person while gaining 0.33 QALYs (Quality-Adjusted Life Years). Those with poor inhaler techniques, regardless of the regularity of inhaler use , still achieved QALY gains but at a higher cost over 5 years. Economic benefits were more pronounced for patients with difficult-to-treat severe asthma, 101 with cost savings between €3207 ($3377) and €26,309 ($27,703) per person over 10 years, largely due to reduced biologic therapy costs. These findings suggest that targeting the right patient group is key to maximising both clinical benefits and cost-effectiveness of interventions using digital inhalers.
Targeted patient groups for digital inhaler adherence interventions
Building on the need to prioritise patients most likely to benefit from interventions, target groups have been identified based on previous evidence.
103
We propose the following prime candidates: • Patients having severe disease and poor adherence: Patients with severe asthma (e.g., GINA steps 4-5) or COPD with high healthcare utilisation burden stand out to benefit significantly. For these individuals, digital inhaler monitoring enables early risk detection and timely treatment adjustment. • Responder group: Objective adherence monitoring mapped with changes in biomarkers such as blood eosinophil counts or fractional exhaled nitric oxide (FeNO) could facilitate precision therapies. Given that only a subset of COPD patients with type 2 inflammation benefit from ICS, biomarker-driven insights could refine the treatment target group and thresholds. Currently, this approach is rarely utilised in COPD studies. • New users of inhaler regimes: For patients starting inhaler therapy, digital tools help establish proper technique and consistent usage habits from the outset. • Patients in rural settings: Employing digital platforms holds promise for residents in rural areas where adherence is often hindered by access or education gaps. Favouring feedback from participants and success were received in both asthma and COPD.41,102,103 As smartphone access expands, digital platforms can improve clinical outcomes for hard-to-reach populations. • Research participants: A systematic review of research trials examining the efficacy of add-on therapies in asthma revealed that background inhaler adherence was drastically overlooked.
104
Only 23% of studies reported adherence and rarely used objective methods.
104
Trials that did track adherence saw reduced variance in FEV1 outcomes, achieving higher statistical power. Thus, digital inhalers should become the new standard for research examining treatment efficacy. • Patients on AIR and MART regimes: Recent guidelines endorsed the shift towards AIR and MART regimes from traditional reliever use.2,105 Longitudinal evidence is limited on both these regimens, especially on the prevalence of symptom-driven inhaler overuse behaviour among those with advanced disease.77,106 Moreover, our current adherence benchmarks (i.e., 75%–80%)34,107,108 largely stem from studies using prescription refill data, which may overestimate adherence. Studies using EIM rarely achieved that target,34,43,102 suggesting that traditional targets might be overly optimistic for certain subgroups. Evidence on MART regimes in the severe asthma group receiving biologics further supports this, as patients were clinically well at lower but regular ICS exposure.9,105,109 For COPD patient groups, studies, even with self-reports, reported high daily ICS exposure, 900 mcg budesonide equivalent dose.
110
As the MART prescription gains traction, EIM can help characterise the true inhaler use pattern in this cohort.
34
Future direction and proposed adherence intervention model
Digital inhaler platforms demonstrated a great potential to enhance patient care. However, to avoid exacerbating existing disparities, digital solutions must prioritise accessibility and user-friendliness across diverse patient demographics. Features such as voice commands, large displays, and multilingual options are important. Another key detail that must be worked out is the technical and interoperability standards so that the purchased technology can be integrated efficiently. With increasing smartphone penetration globally including in developing countries, it is possible that patients can potentially install digitalised health apps and utilise features such as app-based reminders and monitoring of physiological parameters without extra cost. Additionally, the environmental impact also needs consideration in prescribing decisions, emphasising initiatives for eco-friendly disposal, remanufacturing, and incentives for returning used devices among patients.
Current evidence proves that the personalisation of adherence behaviour (e.g., the right digital model for the right patient) is critical. However, what is lacking is the mechanistic aspect of how the treatment impacted patients to prioritise the patient selection or identification of responder groups. Data from large pilot studies fitting these platforms to the actual healthcare system is in demand. To facilitate an effective digital inhaler adherence intervention, we propose key pillars that incorporate exploring behavioural insights and biomarker profiling while examining optimal levels of digital technology support for an individual (see Figure 1). This approach will add sophistication to digital inhaler studies, enhancing their impact and value in real-world applications. Key elements to be considered for future digital adherence intervention study designs. EIM: electronic inhaler adherence monitoring; FeNO: fractional exhaled nitric oxide; BEC: blood eosinophil count; HRQoL: health-related quality of life; HCP: healthcare practitioners. Figure adapted from Aung et al.’s work in the European Respiratory Review
55
.
Conclusion
Digital inhalers are at the forefront of personalised respiratory care. Beyond their technological advancements, they serve as catalysts for a broader shift in care delivery—one that prioritises patient-centred approaches and integrates behavioural insights with clinical data. Although digital inhaler platforms have made remarkable strides in improving adherence, their full potential remains untapped. Moving forward, continued innovation and collaboration between stakeholders, healthcare providers, and patients will be essential to unlock the full potential of these digital solutions.
Supplemental Material
Supplemental Material - The evolving landscape of digital inhaler platforms and adherence support in chronic airways disease
Supplemental Material for The evolving landscape of digital inhaler platforms and adherence support in chronic airways disease by Hnin Aung, Anna Murphy, Neil J. Greening in Chronic Respiratory Disease
Footnotes
Funding
The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study/research is supported by the National Institute for Health and Care Research (NIHR) Leicester Biomedical Research Centre (BRC).
Declaration of conflicting interests
The authors declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: H. Aung has no conflict of interest. A. Murphy has received funding for research studies, consultancy agreements, and honoraria for presentations from AstraZeneca, Chiesi, Orion, and Sanofi. N.J. Greening has received honoraria for lectures, conference travel and advisory boards from AstraZeneca, Boehringer Ingelheim, Chiesi, GlaxoSmithKline, Pulmonx, Roche and Sanofi and received grants and consultation fees (paid to institution) from Genentech, Roche and GlaxoSmithKline.
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References
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