Prediction of dementia of Alzheimer type by different types of subjective cognitive decline

Abstract

Introduction: Subjective cognitive decline (SCD) is a risk condition for dementia, including dementia of Alzheimer type (DAT). Methods: We report sensitivity, specificity, positive and negative predictive values (PPV, NPV) for conversion to all-cause dementia, and DAT in different SCD types (decline in memory, assocated worries, longitudinal consitency, of the AgeCoDe study (n = 2.402, 12 years follow-up). Results: 82.7% of those converting to any dementia and 84.4% of those converting with DAT at follow-up, reported memory decline and fulfilled criteria of SCD at least at one time point before. SCD with worries at two consecutive time points showed a specificity of 92.2% for any dementia and also for DAT as well as a PPV of 44.3% for any dementia and of 36.9% for DAT at follow-up at the expense of low sensitivity. Discussion: Different SCD subtypes were either sensitive or specific for future allcause dementia and DAT in cognitively unimpaired individuals. Modest PPV of the most specific SCD subtypes were achieved in this low prevalence population.

Clinical diagnosis of Alzheimer's disease: recommendations of the International Working Group

“…10. SMC and SCD, when isolated and not supported by objective cognitive impairment, are not specific enough to be considered as part of the AD phenotype 85 . In cognitively unimpaired individuals, self-reported complaints and complaints reported by an informant should be clearly distinguished as the latter are more at-risk of progression 86 and merit a closer follow-up with regular clinical and neuropsychological evaluations.…”

Translation, cross-cultural adaptation, and validity of the Brazilian version of the Cognitive Function Instrument

“…as the criterion to define the SCD group. However, as there is no gold standard questionnaire for the diagnosis of SCD, we opted for a question used in other studies that showed a good predictive value for the progression to MCI or dementia 3,32,33 .…”

The Global Deterioration Scale for Down Syndrome Population (GDS-DS): A Rating Scale to Assess the Progression of Alzheimer’s Disease

“…Furthermore, recent studies in the general population suggest different initial stages on the dementia continuum. In this sense, a subjective cognitive decline (SCD) stage has been proposed as a risk condition announcing possible dementia [ 16 , 17 ], but it must be supported by objective cognitive impairment to be considered part of the AD continuum [ 18 ]. Additionally, mild behavioral impairment (MBI) [ 19 , 20 ] has been proposed as a prodromal neuropsychiatric stage of emergent dementia.…”