Intact global cognitive and olfactory ability predicts lack of transition to dementia

Alzheimers Dement. 2020 Feb;16(2):326-334. doi: 10.1016/j.jalz.2019.08.200. Epub 2020 Jan 4.


Introduction: Odor identification deficits characterize Alzheimer's disease and other dementias. We examined if intact performance on brief cognitive and odor identification tests predicts lack of transition to dementia.

Methods: In an urban community, 1037 older adults without dementia completed the 40-item University of Pennsylvania Smell Identification Test, which includes the 12-item Brief Smell Identification Test (B-SIT). Data from 749 participants followed up for 4 years were analyzed.

Results: In covariate-adjusted survival analyses, impairment on the Blessed Orientation Memory Concentration Test and B-SIT each predicted dementia (n = 109), primarily Alzheimer's disease (n = 101). Among participants with intact olfactory (B-SIT ≥ 11/12 correct) and cognitive (Blessed Orientation Memory Concentration Test ≤ 5/28 incorrect) ability, 3.4% (4/117) transitioned to dementia during follow-up with no transitions in the 70-75 and 81-83 years age group quartiles.

Discussion: Odor identification testing adds value to global cognitive testing, and together can identify individuals who rarely transition to dementia, thereby avoiding unnecessary diagnostic investigation.

Keywords: Cognition; Dementia; Diagnosis; Investigation; Olfaction.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Aged, 80 and over
  • Cognition / physiology*
  • Dementia / diagnosis*
  • Female
  • Healthy Volunteers*
  • Humans
  • Male
  • Neuropsychological Tests / statistics & numerical data
  • Olfaction Disorders / diagnosis
  • Smell / physiology*