Over the next few years, our data-rich, interconnected world could offer important new insights into asthma’s epidemiology and pathogenesis

Inhalers have come a long way since the pressurised metered dose device entered clinical practice in 1956.¹

Since then, there have been remarkable advances in diagnosis, drugs and delivery devices. Yet according to Asthma UK, every 10 seconds someone, somewhere in the UK has a potentially lifethreatening exacerbation. During 2017, 1,320 people in England and Wales died from asthma – yet Asthma UK says that two-thirds of these deaths were preventable.

We live in an increasingly connected world. Asthma care is no exception. High-tech inhalers can remind patients to take their medication and assess adherence, asthma control and possible triggers. Meanwhile, ‘big data’ analyses, which can include information captured by inhalers, offer the prospect of unprecedented insights into this common disease.

As a 2017 report from Asthma UK suggests, smart inhalers represent a “major opportunity for people with asthma, healthcare professionals and the NHS to use data from these devices over the coming decade to improve asthma outcomes in the UK”.²

Improving adherence

Poor adherence is an ongoing problem in asthma – many people simply forget to use their inhaler, especially if they feel better.

A study from New Zealand found that an inhaler with audiovisual reminders improved adherence with inhaled corticosteroids and asthma outcomes in patients aged six to 15 years who presented to the emergency department with an exacerbation. All 220 children enrolled used the same device, but the reminders were switched off in the inhalers used by the 110 controls. Researchers followed the children at two, four and six months.³

Median adherence was 84 per cent in children using the audiovisual reminders, compared with 30 per cent among controls. Adherence fell in both groups: mean adherence at two months was 91 and 40 per cent in children receiving reminders and controls respectively, declining to 79 and 27 per cent respectively at six months.³

The exacerbation rate differed at two months: 7 and 24 per cent in children receiving reminders and controls respectively. The exacerbation rate did not differ significantly after this, possibly because adherence was too low.³

Smart inhalers can be more sophisticated than simple prompts. Some inhalers, for instance, record the date, time, location and number of actuations. The inhaler passes data to a smartphone and on to a service that presents the information as, for example, web-based dashboards, short messages and e-mails. These offer a personalised assessment of asthma control, adherence and possible triggers.^4,5

A study from the US used this approach to track shortacting beta-agonist (SABA) use in 120 people. During a 30-day baseline, patients used SABA a mean of 0.44 times a day. This fell by 39 per cent in the month after they started using the device. The proportion of symptom-free days was 77 and 86 per cent respectively.

These improvements – and the increase in the proportion of people with well-controlled asthma – were sustained during the year-long study. For example, in the 35 patients studied at month 12, the proportion of symptom-free days reached 95 per cent.⁴

Another study enrolled 495 patients and compared the same system with routine care over 12 months. In people whose initial Asthma Control Test (ACT) scores suggested they had uncontrolled asthma, 63 per cent of those using the system showed controlled asthma compared with 49 per cent receiving routine care.⁵

Big data

High-tech inhalers, environmental sensors and data from smart phones allow the collection of far more information about asthma than ever before. Indeed, the analysis of a massive number of patients – ‘big data’ – recently allowed the first description of the UK’s general asthma population.

The researchers split the records of 424,326 patients with current asthma into four groups:

• Younger than five years of age
• 5-17 years old
• 18-54 years old
• Older than 55 years.

Most had mild asthma (steps 1-2 of the BTS guidelines), although this proportion declined markedly in the oldest patients: 67.8 per cent younger than five years; 72.4 per cent 5-17 year-olds; 67.0 per cent 18-54 year-olds; and 43.6 per cent older than 55 years.⁶

In line with this, the proportion of patients who experienced an exacerbation rose with age: 4.27 per 10 person-years in those younger than five years; 1.48 in the 5-17 year-olds; 3.22 in the 18-54 year-olds; and 9.40 in those older than 55 years. The number of deaths from asthma also rose sharply from fewer than five in those younger than five and 5-17 year-olds, to 37 of those aged 18-54 years and 218 in those older than 55 years during median follow-up ranging from one to 5.1 years.⁶

Big data can also integrate several sources, which allows algorithms to examine trends, reveal risk factors (such as environmental triggers detected by a sensor linked to the location captured by the smart phone) and make predictions. For example, researchers developed a model that predicts the number of emergency department visits for asthma in a specific area with approximately 70 per cent precision in “near-real-time” using data from Twitter and environmental sensors (particulate matter, carbon monoxide and nitrogen oxides).⁷

Asthma UK suggests that using data from connected devices could allow fewer face-to-face consultations and more personalised care, help clinicians to manage asthma at scale and facilitate risk stratification.

“By alerting patients and clinicians when symptoms require specific action, smart inhalers could help reduce the complacency that current systems encourage, and facilitate a shift to greater self-care and self-activation,” the report comments.²

As we’ve seen, connected devices can already improve adherence, enhance asthma care and collect insightful data. Clinicians now need to decide how to best use this wealth of data, such as when making clinical decisions about asthma. Realising the full potential, however, means investing in a “significant” research programme covering, for example, accuracy, robustness, user experience and clinical outcomes.”²

Asthma UK concludes that it is important to “have a clear plan to ensure they [connected technologies] are safe, effective and good value for money for all, and to enable rapid access and uptake”.

References

1. Primary Care Respiratory Journal 2006; 15:326
2. asthma.org.uk/get-involved/campaigns/ publications/smartasthma
3. The Lancet Respiratory Medicine 2015; 3:210-9
4. Annals of Allergy, Asthma & Immunology 2017; 119:415-421.e1
5. The Journal of Allergy and Clinical Immunology: In Practice 2016; 4: 455-463
6. Thorax 2018; 73:313-320
7. IEEE Journal of Biomedical and Health Informatics 2015; 19:1216-1223.