Symptom perception and adherence to asthma controller medications

To explore asthma symptom perception and the relationship between asthma symptom perception and adherence to asthma treatment.

Adult patients (N=120) of asthma/allergy specialty clinics, taking Advair as a controller medication, were enrolled in this cross-sectional descriptive study.

Ninety-seven participants completed 4 weeks of daily diaries to assess subjective symptom perception and measured peak expiratory flow rates (PEFR), both done twice daily. Individual perceptual accuracy scores (PAS) were determined by correlating the subjective symptom perception scores with the PEFRs. Measures included demographic variables, illness identity (personal control and treatment control, consequences, and timeline-cyclical subscales of the IPQ-R), asthma severity (FEV1 percentage) and a single-item indicator of perceived asthma severity. Adherence was measured by the Medication Adherence Report Scale (MARS) and by an Advair dose count (percentage of doses taken as prescribed).

Independent t tests comparing adherence rates of good versus poor perceivers were not significant, using either the percentage Advair dose count or the MARS. Multiple regression analyses showed that years with asthma, illness identity, and peak flow variability were all significant explanatory variables for perceptual accuracy.

Peak flow variability adds complexity to the relationship between perceptual accuracy and adherence that warrants further investigation.