The COgnitive-Pulmonary Disease (COgnitive-PD) study: protocol of a longitudinal observational comparative study on neuropsychological functioning of patients with COPD

Introduction Intact cognitive functioning is necessary for patients with chronic obstructive pulmonary disease (COPD) to understand the value of healthy lifestyle guidelines, to make informed decisions and subsequently act on it. Nevertheless, brain abnormalities and cognitive impairment have been found in patients with COPD. To date, it remains unknown which cognitive domains are affected and what the possible consequences are of cognitive impairment. Therefore, objectives of the study described are to determine neuropsychological functioning in patients with COPD, and its influence on health status, daily functioning and pulmonary rehabilitation outcome. Furthermore, structural and functional brain abnormalities and the relationship with cognitive and daily functioning will be explored. Methods and analysis A longitudinal observational comparative study will be performed in 183 patients with COPD referred for pulmonary rehabilitation and in 90 healthy control participants. Demographic and clinical characteristics, activities of daily living and knowledge about COPD will be assessed. Baseline cognitive functioning will be compared between patients and controls using a detailed neuropsychological testing battery. An MRI substudy will be performed to compare brain abnormalities between 35 patients with COPD with cognitive impairment and 35 patients with COPD without cognitive impairment. Patients will be recruited between November 2013 and November 2015. Ethics and dissemination The study has been approved by the Medical Ethics Committee of the University Hospital Maastricht and Maastricht University (NL45127.068.13/METC 13-3-035) and is registered in the Dutch trial register. All participants will provide written informed consent and can withdraw from the study at any point in time. Assessment and home visit data material will be managed anonymously. The results obtained can be used to optimise patient-oriented treatment for cognitively impaired patients with COPD. The findings will be disseminated in international peer-reviewed journals and through research conferences.