van Maurik IS, et al. - Researchers strived to construct biomarker-based prognostic models that enabled determination of future Alzheimer's disease (AD) dementia in patients with mild cognitive impairment (MCI). This study gave biomarker-based prognostic models that could help in determining AD dementia and any type of dementia in patients with MCI at the individual level. They supported clinical decision making and application of biomarkers in daily practice.

• This study belonged to the Alzheimer’s Biomarkers in Daily Practice (ABIDE) project.
• The researchers studied 525 patients with MCI from the Amsterdam Dementia Cohort (longitudinal cohort, tertiary referral center).
• From September 1, 1997, through August 31, 2014, all patients had their baseline visit to a memory clinic.
• They constructed prognostic models by Cox proportional hazards regression with patient characteristics (age, sex, and Mini-Mental State Examination [MMSE] score), magnetic resonance imaging (MRI) biomarkers (hippocampal volume, normalized whole-brain volume), cerebrospinal fluid (CSF) biomarkers (amyloid-β1-42, tau), and combined biomarkers.
• From November 1, 2015, to October 1, 2016, data were examined.
• AD dementia and any type of dementia after 1 and 3 years were the clinical end points.

• Among the 525 patients, 210 (40.0%) were female.
• The mean (SD) age was 67.3 (8.4) years.
• The 3-year progression risk to AD dementia ranged from 26% (95% CI, 19%-34%) in younger men with MMSE scores of 29 to 76% (95% CI, 65%-84%) in older women with MMSE scores of 24 (1-year risk: 6% [95% CI, 4%-9%] to 24% [95% CI, 18%-32%]) on the basis of age, sex, and MMSE score only.
• When MRI results were abnormal, 3- and 1-year progression risks were 86% (95% CI, 71%-95%) and 27% (95% CI, 17%-41%), 82% (95% CI, 73%-89%) and 26% (95% CI, 20%-33%) when CSF test results were abnormal, and 89% (95% CI, 79%-95%) and 26% (95% CI, 18%-36%) when the results of both tests were abnormal.
• On the other hand, after normal MRI results, 3- and 1-year progression risks were 18% (95% CI, 13%-27%) and 3% (95% CI, 2%-5%), 6% (95% CI, 3%-9%) and 1% (95% CI, 0.5%-2%) after normal CSF test results, and 4% (95% CI, 2%-7%) and 0.5% (95% CI, 0.2%-1%) after combined normal MRI and CSF test results.
• Although somewhat lower, the prognostic value of models determining any type of dementia was in the same order of magnitude.
• External validation in Alzheimer’s Disease Neuroimaging Initiative 2 demonstrated that these models were highly robust.