Prognosis of Mild Cognitive Impairment in General Practice: Results of the German AgeCoDe Study

Abstract

PURPOSEThe concept of mild cognitive impairment (MCI) has recently been introduced into the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) as mild neurocognitive disorder, making it a formal diagnosis. We investigated the prognostic value of such a diagnosis and analyzed the determinants of the future course of MCI in the AgeCoDe study (German Study on Ageing, Cognition, and Dementia in Primary Care Patients). METHODSWe recruited 357 patients with MCI aged 75 years or older from primary care practices and conducted follow-up with interviews for 3 years. Depending on the course of impairment over time, the patients were retrospectively split into 4 groups representing remittent, fluctuating, stable, and progressive courses of MCI. We performed ordinal logistic regression analysis and classification and regression tree (CART) analysis.RESULTS Overall, 41.5% of the patients had remission of symptoms with normal cognitive function 1.5 and 3 years later, 21.3% showed a fluctuating course, 14.8% had stable symptoms, and 22.4% had progression to dementia. Patients were at higher risk for advancing from one course to the next along this spectrum if they had symptoms of depression, impairment in more than 1 cognitive domain, or more severe cognitive impairment, or were older. The result on a test of the ability to learn and reproduce new material 10 minutes later was the best indicator at baseline for differentiating between remittent and progressive MCI. Symptoms of depression modified the prognosis. CONCLUSIONSIn primary care, about one-quarter of patients with MCI have progression to dementia within the next 3 years. Assessments of memory function and depressive symptoms are helpful in predicting a progressive vs a remittent course. When transferring the concept of MCI into clinical diagnostic algorithms (eg,, however, we should not forget that three-quarters of patients with MCI stayed cognitively stable or even improved within 3 years. They should not be alarmed unnecessarily by receiving such a diagnosis. 2014;158-165. doi:10.1370/afm.1596. Ann Fam Med INTRODUCTION Mild cognitive impairment (MCI) is a common condition in the elderly with a prevalence of 16.0% in individuals without dementia 1 and an incidence rate of 63.6 (per 1,000 person-years). 2 It is considered to be a transitional state between normal and pathologic cognitive decline. MCI is defined by a cognitive performance below that expected for age and educational attainment, but above a pathologic level as in early dementia. Patients show essentially normal functional activities.Winblad et al 3 classified the clinical presentations of MCI into subtypes according to the impaired cognitive domains, such as memory, orientation, intellectual abilities, and higher cortical functioning. Taking into account memory deficits and the number of cognitive domains impaired, MCI subtypes have been classified as follows: amnestic single domain (impairment of memory only), amnestic multidomain (impairment of memory and 1 or more o...

Conversion to dementia in mild cognitive impairment diagnosed with DSM‐5 criteria and with Petersen's criteria

“…Yet, more than half the DSM5‐MCI cases ( n = 78, 56.1%) were alive and non‐demented 4.5 years after the baseline assessment. Even in a clinical setting, in primary care, using diagnostic criteria ‘very similar to the mild neurocognitive disorder in the DSM‐5' the German AgeCoDe study found that only one‐quarter of patients with MCI have progression to dementia within the next 3 years . Therefore, these results suggest that there is still some way to go for recommending the MCI concept for wider use in population‐based settings.…”

“…In conclusion, this study shows that using more stringent DSM5‐MCI criteria is associated with an increased rate of conversion to dementia and AD, regardless of how progression to dementia is measured, when compared with the more classical P‐MCI criteria . Still, most MCI individuals do not develop dementia, and both clinicians and health administrators should be cautious when transferring the concept of MCI into population‐based settings as this might create unnecessary concern . Incorporation of genetic and biomarker assessments in future studies, in addition to the clinical assessment of MCI, may lend added clarity in the crucial search of early identifiers of individuals at risk of dementia and AD.…”

Mild cognitive impairment in primary care: a clinical review

“…In a large prospective cohort study of patients with MCI, overall, 41.5% of the patients had remission of symptoms with normal cognitive function 1.5 and 3 years later, 21.3% showed a fluctuating course, 14.8% had stable symptoms and 22.4% had progression to dementia 47. However, even in individuals who convert to normal cognition after a diagnosis of MCI, the risk of developing dementia later in life remains high in this population 48.…”

Progression von leichter kognitiver Störung zur Demenz in deutschen Hausarztpraxen: Eine retrospektive, datenbankgestützte Auswertung

“…Die biomarkerorientierte Demenzdiagnostik hat dazu geführt, dass die Wahrscheinlichkeit einer korrekten Diagnosestellung der Alzheimer-Krankheit bereits im Stadium der leichten kognitiven Störung (MCI) möglich ist [1,2]. Die Progression von einer leich-ten kognitiven Störung zu einer Demenz ist gegenwärtig vor allem im Forschungszusammenhang von Interesse [3]. Hausärzten wird eine Schlüsselrolle bei der frühzeitigen Differenzialdiagnostik kognitiver Störungen zugeschrieben [4,5].…”