Protracted Versus New‐Onset Delirium: Diagnostic Challenges

I read with interest the study by Cole and colleagues.1 This is an area of significant interest to many clinicians and researchers given the adverse outcomes associated with delirium. Longer duration and greater severity of delirium are well-recognized risk factors for adverse outcomes of delirium.2-4 The researchers note that, “the participants were reassessed at only two time points, it is possible that some recovered from the index episode of delirium but experienced a second episode at the time of follow-up.” This is an important point to emphasize and is a significant limitation of this study. Unless individuals are assessed daily for delirium, one could not assume that a delirium diagnosis made 1 or 3 months after a delirium diagnosis is protracted delirium. The Confusion Assessment Method (CAM) is a widely used delirium screening tool with high sensitivity and specificity.5 “Is there evidence of an acute change in mental status from the patient's baseline?” is the standardized question for one of the core symptoms of delirium in the CAM. The CAM training manual defines that symptom as “alteration in mental status (e.g., attention, orientation, cognition) that was new or worse for this patient, usually over hours to days.” If one follows the CAM strictly for a diagnosis of delirium, the delirium diagnosed at 1 and 3 months in this study population of older adults with multiple medical comorbidities would be considered a new delirium diagnosis. My point is that this is a thoughtful study of an important clinical observation, but it does not measure the outcomes proposed. Daily delirium assessments until delirium fully or partially resolves would be the best way to test the hypothesis put forth in this study. Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the author and has determined that the author has no financial or any other kind of personal conflicts with this paper. The author is a Board Member for the Society of Liaison Psychiatry in New York. Author Contributions: The author was the sole author of this letter. Sponsor's Role: N/A.