Thesis abstract:

«p»Chronic Obstructive Pulmonary Disease (COPD) is a chronic progressive lung disease characterised by slowly progressive development of airflow limitation. As COPD progresses, patients also begin to experience COPD exacerbations, which are defined as acute worsening of respiratory symptoms that require additional therapy and, in some cases, result in emergency visits or hospitalisation. COPD management is aimed to minimise the impact of COPD symptoms and reduce exacerbations, thereby slowing the progression of COPD. The dominant therapeutic strategy for COPD is the maintenance therapy with Long-Acting Bronchodilators (alone or in combination with another bronchodilator or an inhaler corticosteroid), frequently delivered through Dry Powder Inhaler devices (DPIs). The effectiveness of maintenance therapy for COPD with DPIs depends on a wide range of factors, including inhaler technique. One particular aspect of inhaler use that has also been reported to be important in the use of DPIs in COPD is Peak Inspiratory Flow (PIF), i.e. the force the patient generates to deliver a dose of medication from the inhaler. To achieve a sufficient dose when using DPIs, the patient is required to produce a sufficient PIF. However, some COPD patients with mild and severe obstruction have difficulties achieving sufficient PIF when using DPIs. This is often complicated by the fact that patients often also make other errors when using their inhalers (either because a health care provider has not taught them the correct inhaler technique or it has not been checked over time etc.), and this can overlap with insufficient PIF. Therefore, it is important to understand if a patient has insufficient PIF and the cause, i.e.suboptimal education or patient characteristics, which impact the patient's ability to achieve sufficient PIF, even with education. Regardless of the reason, it is important to ensure that patients have sufficient PIF. Recent studies conducted with patients with severe COPD/during COPD exacerbations/hospital patients have suggested that patients with reduced PIF may have worse COPD-related symptom burdens and increased risk of COPD-related hospitalisations. However, the proportion of patients with suboptimal PIF in a community sample of patients is still unknown, as well as the proportion of patients that can be trained to have sufficient PIF. Furthermore, in primary care, little is known about the associations of PIF, inhalation technique, medication adherence and patients' preferences with the effectiveness of maintenance therapy. This study focuses on people in the community using DPIs as a maintenance treatment for stable COPD to identify the prevalence of suboptimal PIF, the proportion of suboptimal PIF patients who can be trained to achieve the sufficient PIF, an association of PIF, inhalation technique errors, and medication adherence with a number of exacerbations and healthcare resources utilisation. This study also aims to study patient-inhaler interaction and patients' perceptions of their inhalers, their ability to use them, the importance of the inhaler being matched to their breathing capacity and the role they feel they could play in determining which inhaler is best for them. Some of these factors have been shown to be linked to patient satisfaction and patients' willingness to use their inhalers, however much still fails to be understood. The study will take a form of a cross-sectional observational study and will utilise both quantitative and qualitative research methodologies. The study population will be people aged 40 or older who are receiving COPD maintenance therapy through DPIs in the past three months or longer. In Phase 1 of the study (quantitative phase), data relating to the health status, symptom control, adherence, an assessment of PIF, self-reported exacerbation history and inhalation technique errors will be collected. Phase 2 of the study (qualitative phase) will involve interviewing patients from Phase 1, in order to gain new insights, knowledge and understanding relating to the participants' experience with inhaler devices, particularly regarding preference, choice, adherence and medication history.«/p»