Cognitive dysfunction in patients with chronic obstructive pulmonary disease--a systematic review.

Substantial healthcare resources are spent on chronic obstructive pulmonary disease (COPD). In addition, the involvement of patients in monitoring and treatment of their condition has been suggested. However, it is important to maintain a view of self-care that takes differences in cognitive ability into account. The aim of this study was to determine the occurrence and severity of cognitive dysfunction in COPD patients, and to assess the association between severity of COPD and the level of cognitive function.