Metered-dose inhaler adherence in a clinical trial

Area of Science:

• Respiratory Medicine
• Clinical Pharmacology
• Medical Device Technology

Background:

• Accurate assessment of medication adherence is crucial for evaluating treatment efficacy in chronic respiratory diseases.
• Traditional methods like self-report and canister weighing may not accurately reflect actual patient inhaler usage patterns.

Purpose of the Study:

• To compare the accuracy of self-report and canister weight in measuring inhaler adherence against a microprocessor monitoring device.
• To investigate actual inhaler usage patterns in participants of the Lung Health Study.

Main Methods:

• Adherence was assessed over 4 months using self-report (n=95) and canister weight change (n=70).
• Inhaler actuations were recorded using the Nebulizer Chronolog (NC), a microprocessor monitoring device.
• Data from self-report and canister weight were compared with NC data.

Main Results:

• Seventy-three percent of participants self-reported adherence, but NC data showed only 15% used the inhaler ≥2.5 times daily.
• Canister weight overestimated adherence; only 62% of monitored inhaler sets contained the prescribed two actuations per dose.
• Fourteen percent of participants exhibited patterns of excessive actuation ( >100 times in 3 hours), suggesting deliberate medication dumping.

Conclusions:

• Self-report and canister weighing significantly overestimate adherence to prescribed inhaler regimens.
• A notable proportion of participants may deliberately manipulate inhaler usage to feign compliance.
• Microprocessor monitoring devices provide a more objective measure of inhaler adherence and usage patterns.