Digital inhaler improves short-term medication adherence, long-term asthma control

Key takeaways:

• The electronic monitoring device and app provide reminders, motivational messages and symptom information.
• Adherence improved after 1 week in the intervention group but fell through 12 months.

Electronic monitoring devices supported short-term adherence to asthma medication, with sustained improvements in asthma control, according to an abstract presented at the European Respiratory Society International Congress.

However, evidence for long-term adherence was lacking, Susanne van de Hei, MS, a PhD candidate and general practitioner trainee at Universitair Medisch Centrum Groningen, General Practitioners Research Institute, the Netherlands, said during her presentation.

“Medication adherence rates in asthma patients are low,” she said. “Digital — or smart — inhalers are devices that can provide objective data on medication adherence by electronically monitoring the inhaler use.”

Previous studies have indicated that these devices can improve adherence in the short term of 6 months or less, van de Hei said, but the long-term effects of their use on adherence and asthma control remain unknown.

The Acceptance study recruited 164 adults with Asthma Control Questionnaire (ACQ) scores of 0.75 or higher, with 82 (39% men; mean age, 48.1 years) in the intervention group and 82 (43.9% men; mean age, 47 years) in the control group.

At baseline, the control group had mean adherence of 65.4% and a ACQ-5 score of 1.7 ± 0.8, and the intervention group had mean adherence of 62.6% and a ACQ-5 score of 1.6 ± 0.7.

Each patient used a Symbicort Turbuhaler (budesonide/formoterol, AstraZeneca) inhaler with an attached electronic monitoring device. In the intervention group, this device was connected to the Turbu+ Insights mobile app.

“We started with a run-in period of 6 weeks, in which we electronically monitored inhaler use without patients being able to view their data,” van de Hei said.

During the 12-month study period, the intervention group and their physicians were able to access their inhaler usage data via the app, which also provided reminders and motivational messages while tracking asthma symptoms. The control group and their physicians were not able to access these data.

After the baseline visit, patients answered mailed questionnaires at 3 and 9 months and participated in remote visits via video conferencing at 6 and 12 months.

At week 2, the intervention group had higher adherence (OR = 2.19; 95% CI, 1.63-2.95) than the control group.

“The intervention group was more adherent than the control group,” van de Hei said.

But over time, that difference between the groups decreased until there was no significant difference between the groups at the end of the study (OR = 1.23; 95% CI, 0.91-1.66).

“In the first half year, you see a pretty significant difference, and then afterwards it gets a bit blurry,” van de Hei said.

Using a generalized linear mix model, the researchers found a 60% (95% CI, 55%-65%) difference in medication adherence in the control group and a 71% (95% CI, 67%-75%) difference in the intervention group, with no overlap in the confidence intervals.

In another generalized linear mix model, the researchers found a significant difference in ACQ-5 scores between the groups (P = .006).

The odds ratio for changes of –0.5 or less in ACQ-5 scores from baseline to 12 months was 3 (95% CI, 1.13-8.35), indicating that the intervention group was three times more likely to reach the minimally important difference, van de Hei said.

“If you use this digital inhaler, that leads to significantly higher medication adherence in the short term and also better ACQ-5 scores,” van de Hei said. “In the long term, we didn’t find a significant difference in medication adherence, but we did find better ACQ-5 scores.”