Attention functions in stable chronic obstructive pulmonary disease: a neuropsychological case-control study

Background: Previous studies have demonstrated some attentional difficulties in exacerbating COPD inpatients. However, such findings are of limited clinical utility and raise issues with generalisability to the majority of COPD patients whose condition is stable. This study aimed to build on, and offer a comparison to, previous investigations by examining attention functions in stable COPD. Methods: Performance of 23 stable COPD patients and 23 matched controls were compared on three attention-based tasks: Attention Network Test, Stroop Colour-Word Task and Hayling Sentence Completion Task. Performance on these tasks was used to examine alerting and orienting attention and response inhibition. Results: No significant differences were identified in between-group comparisons of individual subtest scores. Inspection of between-group effect sizes suggested a slight reduction in alerting and response inhibition abilities in the COPD group. However, the study was underpowered to detect effects at the level observed. Impairment analysis suggested a small-subgroup of COPD participants experienced response inhibition difficulties beyond the threshold for clinical impairment. Conclusions: For most stable COPD patients, any attention difficulties experienced are mild and unlikely to have a notable difference on everyday functioning. However, a small sub-group may be at risk of clinically relevant levels of attentional impairment, which may influence health outcomes