How Well Does Patient Self-Report Predict Asthma Medication Possession? Implications for Medication Reconciliation and Adherence Assessment

Background. Self-report is the most commonly used method for collecting information regarding asthma medication possession and adherence in clinical practice. Objective. To determine the agreement between self-report and pharmacy claims data for asthma medication possession. Methods. This is a retrospective study that examined pharmacy claims data 12 months before and after participants completed a structured asthma survey. This study was performed in a sample of health care workers and dependents > 17 years old in a large, self-insured Midwestern United States health care center. The main outcome measure was agreement (kappa calculation) between self-report and pharmacy claims data of asthma medication possession. Results. Self-report of asthma medication use agreed moderately with pharmacy claims data for short-acting albuterol (kappa = 0.47 +/- 0.03), salmeterol (kappa = 0.79 +/- 0.04), and montelukast (kappa = 0.69 +/- 0.03) but only slightly for inhaled corticosteroids (kappa = 0.18 +/- 0.03) and prednisone (kappa = 0.10 +/- 0.03) (n = 1050 respondents). Both under self-reporting and over self-reporting were common with inhaled corticosteroids (14.4% and 23.1%, respectively) and varied significantly by specific drug type. Conclusions. Self-report moderately agrees with asthma medication possession for most adult asthma patients, though the agreement differs considerably between and within asthma medication classes.