Patient-reported versus objective adherence and exacerbation rates in severe asthma

Introduction: Adherence to maintenance inhaled therapy and correct inhaler technique are essential for good asthma control. In our adult severe asthma new patient multidisciplinary assessment a pharmacy-led medication review confirms adherence to preventer inhalers and prednisolone courses using prescribing records. This enables an accurate assessment of the severity of the patient’s asthma and suitability for biologic therapies. Aim: To evaluate disparity between patient-reported and confirmed adherence to inhaled therapy and prednisolone courses over a 12 month period. Method: Data from 50 consecutive new patient assessments were collected and analysed. Results: 42 (84%) patients reported good adherence and 93% of these (n = 39) had good adherence confirmed by prescription pickup rates over 80%. 12% of patients made one critical error in inhaler technique, and 52% made two or more. Combined good adherence with good technique was only seen in 30% of cases. Patients reported median (IQR) 3.58 (1.00-5.00) prednisolone courses in the previous year; 2.96 (1.00-4.25) were confirmed (Wilcoxon’s p=0.005 for difference). This reduction in confirmed exacerbation rate led to ineligibility for a biologic in 4 cases (8%). Conclusion: Patient reported adherence to inhalers was similar to pharmacy confirmed adherence in our severe asthma cohort. Optimising adherence and technique with specialist pharmacist support plays a vital role in optimising asthma control, and is likely to be needed for the majority of patients. Patients may over report prednisolone courses which can lead to unnecessary changes to asthma treatment and unnecessary biologic therapy.