We thank Drs Grabowski and Kubanek for drawing attention to cognitive impairment as an important factor in the collection of patient-reported outcome (PRO) data with patients undergoing hemodialysis (HD).1 As stated, cognitive impairment including dementia is common in dialysis patients and is associated with poor outcomes.2 However, the nature and prevalence of this cognitive dysfunction is poorly understood and recorded,3 and it is important to understand the temporal effects of dialysis on cognitive status.