Assessing Adherence by Combining the Test of Adherence to Inhalers With Pharmacy Refill Records.

Area of Science:

• Respiratory Medicine
• Pharmacoeconomics
• Clinical Pharmacy

Background:

• The Global Initiative for Asthma (GINA) suggests using both self-report questionnaires and pharmacy refill data to evaluate patient adherence to prescribed medications.
• However, robust clinical evidence supporting this combined strategy for assessing adherence is currently limited.

Purpose of the Study:

• To assess nonadherence to inhaler medications in patients with asthma or chronic obstructive pulmonary disease (COPD) using the validated Test of Adherence to Inhalers (TAI) questionnaire and prescription refill data.
• To determine the level of agreement (concordance) between the TAI questionnaire and pharmacy refill data in identifying nonadherence.

Main Methods:

• A cross-sectional, observational, multicenter study involving 816 patients diagnosed with asthma or COPD.
• Data collection included sociodemographic and clinical information from medical records, and prescription refill data from electronic pharmacy databases.
• Participants completed the 12-item TAI during a routine clinical visit. Nonadherence was defined as a TAI score below 50% or a pharmacy refill rate (PRR) below 80% within the preceding six months.

Main Results:

• The study included 816 patients with a mean age of 60 years.
• Nonadherence rates were 58.1% based on the TAI and 28.6% based on PRR.
• The combined data identified a nonadherence rate of 64.6%, which was statistically significant (P<.0001). Concordance between the TAI and PRR was weak (κ=0.205).

Conclusions:

• The findings support the Global Initiative for Asthma (GINA) recommendations for assessing treatment adherence.
• Concomitant use of the Test of Adherence to Inhalers (TAI) and pharmacy refill data is more effective in identifying nonadherent patients with asthma or COPD compared to using either measure alone.