Background and importance Adherence to medication is very important in chronic diseases, such as asthma. According to the global initiative for asthma (GINA) guidelines, 50% of asthmatic patients on long term therapy fail to take medications as directed, at least some of the time. Furthermore, patients with poor adherence to medication are much more likely to suffer exacerbations.

Aim and objectives To compare the results of subjective adherence tests, such as the validated test of adherence to inhalers (TAI) in asthma with the results of objective adherence tests, such as the dispensing records.

Material and methods In the context of a doctoral thesis starting in January 2020 in a university hospital, every patient prescribed with a biologic agent for severe eosinophilic asthma had periodic interviews with a pharmacist during dispensation of the drugs. A total of 32 patients were recruited and, among other details, patients answered the TAI and their dispensing records for maintenance inhalers were checked by a pharmacist. The results of the TAI (0 to 50) and the dispensing records (0% to 100%) were compared, and the Pearson coefficient of correlation was calculated.

Results All patients answered the TAI and the mean result was 49.25 (46–50). The mean result for the dispensing records was 59% (0–100%) in the previous 6 months. The Pearson coefficient of correlation for these variables was 0.22.

Conclusion and relevance The coefficient was >0, which suggests a positive correlation, but it was also very close to 0, which indicates that the correlation was very week. Usually, asthmatic patients know the TAI as many pneumologists use it as a tool to calculate adherence, and therefore they know they are expected to get 50/50 in the test. However, the dispensing records are an objective method to measure adherence of patients and although it is not a substitute for the TAI, it should be complementary. When a patient with poor adherence is detected, pharmacists can play an important role with motivational interviews.

Conflict of interest No conflict of interest