OBJECTIVES

To measure adherence to inhaled corticosteroid (ICS) therapy using prescription claims and a patient survey, to identify local adverse events (LAEs) from the patient perspective and from medical records, and to evaluate the association between LAEs and adherence to ICS therapy.

STUDY DESIGN

Survey administration and claims-based and medical record-abstracted data.

METHODS

Patients aged 6 to 64 years with persistent asthma (defined using an established algorithm) and at least 2 ICS prescriptions were selected from a claims database (1999-2006) of a central Massachusetts medical group practice. Prescription claims were used to calculate the ICS medication possession ratio (MPR). A survey obtained information about patient-reported adherence to ICSs using the Morisky scale and a visual analog scale (VAS) and about LAEs using the validated Inhaled Corticosteroid Questionnaire. Medical records of survey respondents were abstracted for LAEs.

RESULTS

Among 372 survey respondents, 2.7% met the claims-based measure of good adherence (MPR, > or =80%). Patient-reported adherence was much higher; 20.7% of patients were highly adherent based on the Morisky scale (score, 0) and 55.4% based on the VAS (score, > or =80%). Medical record review identified 27.2% of patients having at least 1 LAE within 1 year after the ICS index date, but 47.3% of patients reported being bothered at least "quite a lot" by LAEs. Multivariate analysis indicated that unpleasant taste was significantly related to lower adherence based on the Morisky scale (P = .02).

CONCLUSIONS

Patient-reported adherence and LAEs were higher than those measured from claims or medical records. Unpleasant taste seems to be associated with lower adherence based on the Morisky scale.