Evaluation of cognitive performance based on the ability to copy a simple drawing. Evaluation of cognitive performance based on the ability to copy a simple drawing. Cognitive impairment is a negative predictor of survival in chronic obstructive pulmonary disease patients. Black line: normal copying drawings with landmarks and no hypoxaemia; blue line: normal copying drawings with landmarks and hypoxaemia; green line: impaired copying drawings with landmarks and no hypoxaemia; red line: impaired copying drawings with landmarks and hypoxaemia. Reproduced from [74] with permission from the publisher. Arnaud Cavaillès et al. Eur Respir Rev 2013;22:454-475 ©2013 by European Respiratory Society