AIMS: To conduct a psychometric analysis to determine the adequacy of instruments that measure cognition in Alzheimer's disease trials. BACKGROUND: Both the Alzheimer's Disease Assessment Scale - Cognition (ADAS-Cog) and the Neuropsychological Test Battery (NTB) are validated outcome measures for clinical trials in Alzheimer's disease and are approved also for regulatory purposes. However, it is not clear how comparable they are in measuring cognitive function. In fact, many recent trials in Alzheimer's disease patients have failed and it has been questioned if ADAS-Cog still is a sensitive measure. MATERIALS AND METHODS: The present paper examines the psychometric properties of ADAS-Cog and NTB, based on a post hoc analysis of data from a clinical trial (NCT01024660), which was conducted by AstraZeneca, in mild-to-moderate Alzheimer's disease (AD) patients, with a Mini Mental State Examination (MMSE) Total score 16-24. Acceptability, reliability, different types of validity and ability to detect change were assessed using relevant statistical methods. Total scores of both tests, as well as separate domains of both tests, including the Wechsler Memory Scale (WMS), Rey Auditory Verbal Learning Test (RAVLT) and Delis-Kaplan Executive Function System (D-KEFS) Verbal Fluency Condition, were analyzed. RESULTS: Overall, NTB performed well, with acceptable reliability and ability to detect change, while ADAS-Cog had insufficient psychometric properties, including ceiling effects in 8 out of a total of 11 ADAS-Cog items in mild AD patients, as well as low test-retest reliability in some of the items. DISCUSSION: Based on a direct comparison on the same patient sample, we see advantages of the NTB compared with the ADAS-Cog for the evaluation of cognitive function in the population of mild-to-moderate AD patients. The results suggest that not all of ADAS-Cog items are relevant for both mild and moderate AD population. CONCLUSIONS: This validation study demonstrates satisfactory psychometric properties of the NTB, while ADAS-Cog was found to be psychometrically inadequate.
AIMS: To conduct a psychometric analysis to determine the adequacy of instruments that measure cognition in Alzheimer's disease trials. BACKGROUND: Both the Alzheimer's Disease Assessment Scale - Cognition (ADAS-Cog) and the Neuropsychological Test Battery (NTB) are validated outcome measures for clinical trials in Alzheimer's disease and are approved also for regulatory purposes. However, it is not clear how comparable they are in measuring cognitive function. In fact, many recent trials in Alzheimer's diseasepatients have failed and it has been questioned if ADAS-Cog still is a sensitive measure. MATERIALS AND METHODS: The present paper examines the psychometric properties of ADAS-Cog and NTB, based on a post hoc analysis of data from a clinical trial (NCT01024660), which was conducted by AstraZeneca, in mild-to-moderate Alzheimer's disease (AD) patients, with a Mini Mental State Examination (MMSE) Total score 16-24. Acceptability, reliability, different types of validity and ability to detect change were assessed using relevant statistical methods. Total scores of both tests, as well as separate domains of both tests, including the Wechsler Memory Scale (WMS), Rey Auditory Verbal Learning Test (RAVLT) and Delis-Kaplan Executive Function System (D-KEFS) Verbal Fluency Condition, were analyzed. RESULTS: Overall, NTB performed well, with acceptable reliability and ability to detect change, while ADAS-Cog had insufficient psychometric properties, including ceiling effects in 8 out of a total of 11 ADAS-Cog items in mild ADpatients, as well as low test-retest reliability in some of the items. DISCUSSION: Based on a direct comparison on the same patient sample, we see advantages of the NTB compared with the ADAS-Cog for the evaluation of cognitive function in the population of mild-to-moderate ADpatients. The results suggest that not all of ADAS-Cog items are relevant for both mild and moderate AD population. CONCLUSIONS: This validation study demonstrates satisfactory psychometric properties of the NTB, while ADAS-Cog was found to be psychometrically inadequate.
Authors: Holly Posner; Rosie Curiel; Chris Edgar; Suzanne Hendrix; Enchi Liu; David A Loewenstein; Glenn Morrison; Leslie Shinobu; Keith Wesnes; Philip D Harvey Journal: Innov Clin Neurosci Date: 2017-02-01
Authors: Roos J Jutten; Sietske A M Sikkes; Wiesje M Van der Flier; Philip Scheltens; Pieter Jelle Visser; Betty M Tijms Journal: Neurology Date: 2021-06-01 Impact factor: 11.800
Authors: Roos J Jutten; John Harrison; Philippe R Lee Meeuw Kjoe; Esther M Opmeer; Niki S M Schoonenboom; Frank Jan de Jong; Craig W Ritchie; Philip Scheltens; Sietske A M Sikkes Journal: Alzheimers Dement (Amst) Date: 2017-12-27
Authors: Roos J Jutten; John Harrison; Frank Jan de Jong; André Aleman; Craig W Ritchie; Philip Scheltens; Sietske A M Sikkes Journal: Alzheimers Dement (N Y) Date: 2017-02-09
Authors: Roos J Jutten; John E Harrison; Philippe R Lee Meeuw Kjoe; Silvia Ingala; R Vreeswijk; R A J van Deelen; Frank Jan de Jong; Esther M Opmeer; André Aleman; Craig W Ritchie; Philip Scheltens; Sietske A M Sikkes Journal: Alzheimers Res Ther Date: 2019-05-15 Impact factor: 6.982