Validity of a remote supervised preclinical Alzheimer’s disease cognitive composite (PACC) score in preclinical and prodromal Alzheimer’s disease.

Abstract

AbstractBackgroundNeuropsychological tests administered to individuals in locations different from the assessor (i.e., remote assessment) can provide substantial reductions in patient burden, study cost and barriers to access. However, such tests must be optimized and validated for use in remote settings. The preclinical cognitive composite score (PACC) is derived from neuropsychological tests of episodic memory, complex attention, and general mental status. This study determined whether a set of neuropsychological tests of these domains, which can provide a PACC score, can be given in a remote supervised setting and remain sensitive to AD related cognitive impairment.MethodOlder adults classified as cognitively unimpaired (CU, n = 30), preclinical AD (n = 30) or prodromal AD (n = 25), with conventional PACC scores known, completed three computerized tests; the International Shopping list Test (ISLT), Continuous Paired Associate Learning Test (CPAL) and the International Digit Symbol Substitution Test, while supervised by a neuropsychologist in in‐clinic and remote settings. All individuals then completed the remote assessments two more times 7days (+/‐4 days) apartResultMain performance measure from each test on each assessment was standardized using the mean and SD of the CU group, assessed under supervision, at baseline. Standardized scores for each assessment were then averaged to yield a PACC score. There was no difference in rates of missing data or group mean score on individual test scores or PACC score, between in‐clinic and remote settings. Compared to the CU group, impairment in performance on the digital PACC in the prodromal AD was substantial (z = ‐1.56) but equivalent between in clinic (9z = 1.57) and remote (z = ‐1.56) settings. Performance on the digital PACC was slightly worse in the preclinical AD group (z = –0.42) but did not differ for settings. The reliability of the digital PACC score was very high (r = 0.87).ConclusionThe digital PACC derived from neuropsychological tests given in remote supervised contexts is acceptable, valid, reliable and sensitive to AD related cognitive impairment when given in‐clinic or remotely.