Background: Cognitive impairment frequently occurs in elderly COPD patients, but little is known about its prognostic implications. We aimed at evaluating the prognostic role of cognitive impairment in patients with severe COPD.
Methods: Our series consisted of 149 stable patients (mean [+/- SD] age, 68.7 +/- 8.5 years) with COPD and a Pao(2) of < 57 mm Hg at rest (n = 97) or at the end of the 6-min walking test (n = 37) who were enrolled in a prospective observational study. After a multidimensional baseline assessment, patients were followed up by telephone calls for a mean duration of 32.5 +/- 9.2 months (minimal follow-up duration, 24 months); 134 patients were successfully tracked. We used multivariable Cox proportional hazard analysis to identify predictors of death among clinical/functional variables that previously were shown to have prognostic implications and among neuropsychological indexes selected on the basis of univariate analysis.
Results: We observed 29 deaths over a median follow-up time of 32 months. Only the two following variables were independently associated with the outcome: an abnormal score on the copy with landmark test (hazard ratio [HR], 2.93; 95% confidence interval [CI], 1.34 to 6.39); and a 6-min walk distance of < 300 m (HR, 3.46; 95% CI, 1.15 to 10.5). A Pao(2) of < 57 mm Hg at rest (HR, 2.19; 95% CI, 0.93 to 5.18) and an FEV(1) of < 40% predicted (HR, 2.74; 95% CI, 0.99 to 7.57) were nearly significantly associated with the outcome, while Paco(2), body mass index, physical dependence, comorbid diseases, and the impairment of cognitive domains other than drawing impairment were unrelated to the outcome.
Conclusions: Drawing impairment is a risk factor for mortality and might improve the assessment of hypoxemic COPD patients.