Characteristics of Reliever Inhaler Users and Asthma Control: A Cross-Sectional Multicenter Study in Portuguese...

SABA overuse might indicate poorly managed or uncontrolled asthma and be responsible for poor health outcomes. The aim of this study integrated in new fourth multi-design SABINA+ pillar was to characterize the population using short-acting β₂-agonists for asthma and examine the patterns of its use among community pharmacy customers in Portugal, as well as identify characteristics associated with disease control and explore potential differences between GINA treatment steps.

This cross-sectional multicenter study was conducted in Portuguese community pharmacies between 29 May 2018 and 15 August 2018. Participants were adults (age ≥18 years) self-reporting asthma diagnosis recruited in the context of a short-acting β₂-agonist dispense. A two-part questionnaire (pharmacist interview and self-administered) was used to collect information about sociodemographic characteristics, comorbidities, reliever inhaler use, healthcare resource consumption and self-reported disease control (assessed by the Control of Allergic Rhinitis and Asthma Test - CARAT^®). Descriptive statistics was done to characterize the study sample. After categorizing patients according to GINA steps, based on their therapeutic regimen, we performed an exploratory subgroup analysis to evaluate if there were any differences between such groups in terms of the variables collected. A logistic regression was used to identify the potential determinants of overall disease control.

Around 50.8% of patients were male, and the average age was 52 years old. Half of the patients never smoked, and 51.9% were employed. More than half of the patients report inhaler overreliance - purchasing more than 1 pack in 3 months (65.0%) or using the inhaler on more than 8 days over the previous 4 weeks (50.2%). Of the total number of patients in the study, 79.1% had poorly controlled asthma symptoms, and 78.7% had overall poorly controlled respiratory symptoms. We found statistically significant differences between GINA treatment steps in all sociodemographic characteristics (sex, mean age, education level, employment status); maximum number of SABA uses in 24h, CARAT score (total an asthma sub-score); history of exacerbations requiring ED visits or treatment with OCS for at least 3 days in the previous 12 months. Logistic regression revealed that patients reporting SABA use in more than 8 days in the previous 4 weeks and patients with at least 1 exacerbation requiring treatment with OCS for at least 3 days in the previous 12 months have greater odds of poor disease control [adjusted OR (95% CI): 2.6 (1.3-5.2) and 3.0 (1.3-6.6)].

Based on the results of this study, it can be inferred that the asthma population using SABA is largely uncontrolled and uses reliever inhalers excessively.