Introduction: Patients with severe asthma often complain of fatigue and difficulty concentrating, which affects their work and family life. Asthma is known to be associated with cognitive impairment, but the level and severity has not been described in severe eosinophilic asthma.

Aims: To investigate the frequency, pattern, and severity of cognitive impairment in patients with poorly controlled severe eosinophilic asthma.

Methods: Cognitive impairment was assessed in the 3TR Asthma Biologics Cohort study, in patients with severe eosinophilic asthma before commencing a biological treatment. Objective cognitive functions were assessed with a performance-based test battery consisting of screening for cognitive impairment with the Psychiatry Danish Version and the trail Making Test-Part B: Verbal learning and memory, working memory, verbal fluency, processing speed and executive function. Subjective cognitive functions were assessed with the Cognitive Failures Questionnaire.

Results: In the 18 patients assessed, 50% to 56% had clinically significant cognitive impairment, depending on the applied cut-off for clinical relevance of cognitive impairment, when compared with their expected performance based on their individual age, education level and gender. Analyses of the pattern and severity of the cognitive impairment revealed that verbal learning and memory function was most severely affected (p<0.04)

Conclusions: Among patients with severe eosinophilic asthma, a large proportion of the patients displayed cognitive impairment with verbal learning and memory being most affected. The effect of biologics on cognitive impairment will be evaluated in the 3TR-ABC study.