Assessment of the inhalation technique and adherence to therapy and their effect on disease control in outpatients with asthma

Abstract

Objectives The objective of this study was to assess correct use of inhaler devices, adherence to inhaler corticosteroid treatment and their effects on asthma control. Methods This study was a prospective, single-centre, observational study conducted between July and February 2016 at Al-Makased Hospital, respiratory outpatient clinic. Inhaler technique of asthma patients using pressurized metered-dose inhalers or dry powder inhalers (Turbuhaler (TH) and Accuhaler DiskusTM (ACC)) were assessed against published inhaler technique checklists. Asthma control variables measured using Asthma Control Test (maximum 25, higher score corresponding to better asthma control) were assessed, and adherence to asthma medications was assessed by Morisky adherence scale. Key findings Two hundred and twenty patients were recruited in the study. The mean age was 42.3 15.2 years and 59.1% were male. One hundred and seventeen (53.2%) were using TH, 60 (27.3%) were using ACC and 43(19.5%) were using MDIs. Only 22 (10%) were smoker and only 48 (21.8%) patients were their asthma controlled (ACT score >20). The devices were used correctly by 79.1% of patients using MDI, 69% of ACC and 55.6% of TH users (P > 0.001). The most common improper step was ‘forceful inhalation’ (65.4%) made by the MDI users, ‘Not exhaling to residual volume’ (58.7%) made by ACC users and ‘Not inhaling deeply enough’ (52.2%) made by TH users. Multivariate analysis showed that the likelihood of having controlled asthma was significantly higher in those with correct inhaler techniques (OR 2.3; 95% CI: 1.08–4.77; P = 0.028), high adherence to medications (OR 2.37; 95% CI: 1.05–4.92; P = 0.03) and having a higher level of education (OR 2.58; 95% CI: 1.19–3.63; P = 0.018). Conclusions It was found that asthma control was better among correct users. Repetitive training about using devices may contribute improving inhaler technique.