An Observational, Cross-sectional Study of Primary Data Collection to Describe Symptoms Over 24 Hours and Their Relationship With Adherence to Respiratory Treatment, Direct Costs and PRO in Stable COPD Patients in Brazil.

Background

Chronic Obstructive Pulmonary Disease (COPD) is a preventable and treatable disease with some significant extrapulmonary effects that may contribute to the severity in individual patients. Its pulmonary component is characterized by airflow limitation that is not fully reversible. The airflow limitation is usually progressive and associated with an abnormal inflammatory response of the lung to noxious particles or gases (i). Although smoking is one of the major and most frequent causes of COPD, other factors may be associated with its development. The narrowing of the airways, which is one of the main features of COPD, results from a combination of small airway disease and parenchymal destruction, as well as structural changes from the chronic inflammatory process. For this reason bronchoconstriction is one of the key targets of pharmacological interventions in the management of COPD.

This disease affects globally around 15% of all adults older than 40 years, resulting in pulmonary and extrapulmonary comorbidities and significant mortality (1,ii). The worldwide prevalence in people aged over 40 years is 10.1% overall, 11.8% for men, and 8.5% for women, according to the BOLD Study (iii). It is the fourth leading cause of death in the world and its prevalence is projected to increase in the coming years due to continued exposure to COPD risk factors (1). Two Latin-American epidemiological studies, the PLATINO Project iv and PREPOCOL v, have provided information on the prevalence of COPD in this region. PLATINO is a study on prevalence of COPD in individuals ≥40 years, carried out in five Latin American cities: Mexico City (Mexico), São Paulo (Brazil), Montevideo (Uruguay), Santiago de Chile (Chile), and Caracas (Venezuela). Using as diagnostic criteria post-BD FEV1/FVC ratio <0.70, the overall prevalence of COPD in PLATINO is 14.3% (ranging from 7.8% in Mexico City to 19.7% in Montevideo) and in the city of São Paulo is 15.8 % (4,vi). Using the lower limit of normal criteria (LLN) of the post- BD FEV1/FVC ratio, the global COPD prevalence in PLATINO is 11.7%. This is even lower (9.5%) when using the post-BD FEV1/VEF6 < LLN ratio (vii). PREPOCOL (5) assessed the prevalence in five cities in Colombia and reported an overall prevalence of 8.9% (from 6.2% in Barranquilla to 13,5% in Medellin).

Symptoms of COPD - including progressive dyspnea, chronic cough, excessive sputum production and decreased exercise tolerance - may considerably affect the patients' daily activities and quality of life (1,viii,ix). COPD symptoms have been reported to be worse at night and in the early morning (x,xi), which may be reflected in disturbed sleep and limitations on morning activities.

Moreover, the health-related quality of life (HRQoL) is being recognized as an important outcome when evaluating patients with COPD and several studies have demonstrated that those patients in more severe disease stages presented worse HRQoL and it varied greatly within each stage of disease severity (xii).