Mapping of Validated Apathy Scales Onto the Apathy Diagnostic Criteria for Neurocognitive Disorders

Background Diagnostic criteria for apathy ( DCA ) in neurocognitive disorders were developed in 2021. As next steps, we assessed whether commonly‐used validated apathy scales map onto the DCA and identified which scales map best. Method Using a modified Delphi process, mapping of the Neuropsychiatric Inventory‐Clinician ( NPI‐C ) Apathy domain and the Apathy Evaluation Scale ( AES ) onto the DCA were assessed by surveying apathy experts. For each item on the scales, experts were asked to evaluate the degree of correspondence to the DCA globally, and the 3 DCA dimensions [diminished initiative, interest, and emotion]. Respondents voted “not at all” (scored as 0), “weakly” (scored as 1), or “strongly” (scored as 2). For each item, if the mean score was <0.5, the item was considered not mapped, for scores >1.5, the item was considered mapped, and items with scores 0.5‐1.5 were discussed further in a virtual consensus meeting. The surveys were then sent to other scientific community members, and the interrater reliability between the two groups was assessed using Cohen’s kappa. Result The surveys were completed by 12 experts. For NPI‐C apathy, 10/11 (90.9%) questions mapped primarily onto one dimension of the DCA: 2 onto “Initiative”, 6 onto “Interest”, and 2 onto “Emotion”. Of NPI‐C Apathy domain items, 9/11 (81.8%) mapped globally onto the DCA. For the AES, 7/18 (38.9%) questions mapped onto different dimensions of the DCA: 4 onto “Initiative”, 2 onto “Interest”, and 1 onto “Emotion”; 6/18 (33.3%) items mapped globally onto the DCA. The mean mapping scores of NPI‐C were significantly higher than those of the AES (t (27) = 2.25, p = 0.032) indicating better performance of NPI‐C in this exercise. These findings were confirmed in a consensus discussion. There was substantial agreement (kappa = 0.621) between the experts and the community group regarding mapping of NPI‐C but only moderate agreement (kappa = 0.553) regarding mapping of AES on the DCA. Conclusion More questions from the NPI‐C Apathy domain mapped strongly and uniquely both globally, and onto the 3 dimensions of the DCA, compared with the AES. Future research using the DCA, NPI‐C Apathy domain, and AES in clinical and research settings are needed to confirm these results.