Long-term predictive accuracy of the 'mild cognitive impairment due to Alzheimer's disease' criteria.

BackgroundThe development and clinical use of biomarkers has dramatically changed the framework of Alzheimer's disease (AD) management, allowing the diagnosis at the mild cognitive impairment (MCI) stage. In 2015 we compared the prevalence and prognosis of AD at the MCI stage according to different criteria available at that time, and we found that the National Institute of Aging-Alzheimer Association (NIA-AA) criteria provided higher predictive accuracy for AD dementia after 3 years. Since then, we adopted these criteria in clinical practice.ObjectiveTo evaluate the long-term predictive accuracy of the 'MCI due to AD - high likelihood' criteria by taking advantage from an extended follow-up in a memory clinic setting.MethodsPatients were diagnosed according to the 'MCI due to AD - high likelihood' criteria and followed up until conversion to dementia.ResultsOne hundred and fourteen patients with 'MCI due to AD - high likelihood' were enrolled in the study and followed-up for 3.0 ± 1.8 [0.4-8.3] years. During the follow-up 106 (93.0%) patients progressed to dementia, 2 (1.8%) had stroke, 6 (5.3%) died, and none remained in MCI or reverted to normal cognitive status. The average survival time remaining in MCI, analyzed with Kaplan-Meier curve, was 3.2 (95% CI 2.9-3.6) years. Using a multivariate Cox proportional hazards regression model, patients with higher Mini-Mental State Examination kept the MCI status longer.ConclusionsThe diagnostic criteria of NIA-AA 'MCI due to AD - high likelihood' have an excellent long-term predictive accuracy in a memory clinic setting.