Neurofilament Light and Cognition after Cardiac Surgery: Reply

We thank Miles et al.¹  for their interest in our recent article examining the association of perioperative concentrations of neurofilament light and cognition after cardiac surgery.²  In their letter, the authors raise the important question of whether kidney disease could confound the association of neurofilament light and cognitive dysfunction. As the authors discuss, the concentrations of blood biomarkers may be altered in patients with chronic kidney disease,³  although the clinical relevance with respect to prediction of cognitive outcomes has not been established.⁴  To address the question of potential confounding as suggested by the authors, we considered postoperative day 1 creatinine concentration (or the next available hospital creatinine if there was not a postoperative day 1 creatinine) as a potentially confounding variable. In the adjusted models (with or without multiple imputation) examining the association of change in neurofilament light with cognitive change from baseline at 1 yr...