Psychometric evaluation of the A‐NKS – a diagnostic instrument to assess impairment of activities of daily living in mild and severe Neurocognitive Disorder according to DSM‐5

Background Activities of daily living functioning (ADL) are relevant in the diagnosis of neurocognitive disorders (NCD). Currently, however, there has been no standardized and validated instrument based on DSM‐5 diagnosis criteria. Our aim was to psychometrically evaluate the differentiated assessment of ADL impairments due to NCD (A‐NKS). Method We interviewed 92 dyads of individuals with either mild NCDs, major NCDs, or cognitively healthy individuals and a relative each and examined reliability, validity, and acceptability of the A‐NKS. Result Both versions had excellent internal consistency and are correlated with other (I)ADL instruments (patient [informant]: Barthel Index: rs = ‐0.26, p ≤ .05 [rs = ‐0.30, p ≤ .01]; Amsterdam IADL: rs = 0.59, p ≤ .01 [rs = 0.48, p ≤ .01]; SIDAM ADL: rs = 0.46, p ≤ .001 [rs = 0.47, p ≤ .001]). Aditionally, there are correlations with the scale autonomy of the WHOQOL‐OLD (rs = ‐0.50, p ≤ .001 [rs = ‐0.37, p ≤ .001]) and physical, as well as cognitive activities (rs = ‐0.39, p ≤ .001 [rs = ‐0.50, p ≤ .001]). All participants found the questionnaire acceptable. Conclusion The A‐NKS shows promise as a valid, reliable and acceptable measure to assess ADL due to neurodegenerative decline in healthy individuals, individuals with mild NCDs and those with major NCD.