Correlation between cognitive impairment and dependence in hypoxemic COPD.

We studied 149 patients with stable chronic obstructive pulmonary disease (COPD). Three clusters were generated (high, mid, and low level of cognitive function) based on 11 neuropsychologic scores; personal independence in basic/instrumental activities of daily living (BADL/IADL) of clusters was compared by discriminant analysis. Pattern of BADL/IADL was cluster-specific in 79.2% of high and 54.9% of low clusters, but only 20.8% of mid cluster. Self-administering drugs, continence, managing money, and dressing items had the greatest discriminatory capacity. Clusters had comparable respiratory function. In older COPD patients, dependence parallels cognitive impairment only to some extent. Indices of COPD severity are poor correlates of dependence.