COPD: Analysing factors associated with a successful treatment

To evaluate if non-adherence to inhaled medications, inhalers mishandling or the prescribers' non-adherence to GOLD strategy are associated with mMRC grade, CAT score, COPD acute exacerbations or FEV₁%.

A cross-sectional study on COPD was conducted in the ambulatory pulmonary clinic of Hospital de Guimarães. Patients ≥40 years diagnosed according to GOLD criteria were recruited consecutively. A survey of demographic and clinical data was used. Adherence was assessed by using the Measure of Treatment Adherence (MTA) questionnaire. Inhalation technique was evaluated by using checklists of correct steps and critical errors, and inhalers' misuse was defined when one or more critical errors were made, whatever the number or types of inhalers in use. To evaluate the prescriber non-adherence to GOLD strategy, the patients' current medication was compared with therapeutic standards proposed by the GOLD 2017 strategy for the same ABCD groups. A statistical analysis was performed with IBM SPSS Statistics for Windows, Version 23.0. Armonk, NY: IBM Corp.

We studied 303 participants, 79.5% males, mean age=67.5 years. A total of 285 completed the MTA questionnaire. Non-adherence was referred by 47 (16.5%) patients, and a significant negative association was found between adherence and CAT score and FEV₁%. 285 patients performed 499 inhalations manoeuvres with 10 different IDs. Inhaler misuse was observed in 113 (39.6%) patients, and was not associated with CAT score, mMRC grade, ECOPD or FEV₁%. We found deviations from the GOLD strategy in 133 (44.3%) patients, which were negatively related to CAT score, mMRC grade and ECOPD.

In the present study we failed to prove a positive association between non-adherence to medication, inhalers mishandling or prescribers' non-adherence to GOLD strategy with symptoms, exacerbations and airflow limitation. Conversely, more symptomatic and more obstructed patients were more adherent to medication, previous ECOPD seems to improve prescribers' adherence to treatment guidelines, and symptoms, ECOPD and FEV₁% were not significantly associated with inhaler technique.