Underdiagnosis of mild cognitive impairment: A consequence of ignoring practice effects

Autor: Jeremy A. Elman, Amy J. Jak, Matthew S. Panizzon, Xin M. Tu, Tian Chen, Chandra A. Reynolds, Daniel E. Gustavson, Carol E. Franz, Sean N. Hatton, Kristen C. Jacobson, Rosemary Toomey, Ruth McKenzie, Hong Xian, Michael J. Lyons, William S. Kremen
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring, Vol 10, Iss 1, Pp 372-381 (2018)
Druh dokumentu: article
ISSN: 2352-8729
DOI: 10.1016/j.dadm.2018.04.003
Popis: Abstract Introduction Longitudinal testing is necessary to accurately measure cognitive change. However, repeated testing is susceptible to practice effects, which may obscure true cognitive decline and delay detection of mild cognitive impairment (MCI). Methods We retested 995 late‐middle‐aged men in a ∼6‐year follow‐up of the Vietnam Era Twin Study of Aging. In addition, 170 age‐matched replacements were tested for the first time at study wave 2. Group differences were used to calculate practice effects after controlling for attrition effects. MCI diagnoses were generated from practice‐adjusted scores. Results There were significant practice effects on most cognitive domains. Conversion to MCI doubled after correcting for practice effects, from 4.5% to 9%. Importantly, practice effects were present although there were declines in uncorrected scores. Discussion Accounting for practice effects is critical to early detection of MCI. Declines, when lower than expected, can still indicate practice effects. Replacement participants are needed for accurately assessing disease progression.
Databáze: Directory of Open Access Journals