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Trajectories of subjective cognitive decline, and the risk of mild cognitive impairment and dementia
Author(s) -
Liew Tau Ming
Publication year - 2020
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1002/alz.036610
Subject(s) - dementia , medicine , cognitive decline , proportional hazards model , cohort , cognition , cognitive impairment , cohort study , gerontology , disease , longitudinal study , pediatrics , demography , psychiatry , pathology , sociology
Background In cognitively‐normal individuals, subjective cognitive decline (SCD) has been reported to predict MCI and dementia (MCI/dementia). However, prior studies mostly captured SCD at single time‐points without considering the longitudinal course of SCD. This study examined whether the trajectories of SCD provide any added information – beyond one‐time assessments of SCD – on the risk of MCI and dementia (MCI/dementia). Method This cohort study included 5,661 participants from the Alzheimer’s Disease Centers across USA, who were ≥50 years and had normal cognition in the first‐four annual visits (Year 1 to Year 4). The participants were evaluated for SCD in the first‐four annual visits (Year 1 to Year 4), and followed‐up almost annually (from Year 4 up to Year 14) for incident MCI/dementia. SCD trajectories – as identified from latent‐class‐growth‐curve‐analysis – were included in Cox‐regression to estimate their risks of MCI/dementia. Result Compared to those without SCD (in the first‐four annual visits), the presence of Intermittent SCD (i.e. reported in 1–2 of the first‐four annual visits) predicted a higher risk (HR 1.4) while Persistent SCD (i.e. reported in 3–4 of the first‐four annual visits) predicted the highest risk (HR 2.2). A quarter of those with Persistent SCD developed MCI/dementia within 4.7 years; in contrast to 5.8 years among those with Intermittent SCD , and 8.0 years among those without SCD. The results remained significant even after adjusting for baseline SCD. Conclusion The findings demonstrate the added utility of SCD trajectories – beyond cross‐sectional assessments of SCD – in identifying high‐risk populations for preventive interventions and trials. They also suggest a potential modification in the current SCD criteria, with the inclusion of ‘persistent SCD over several years’ as one of the key features within SCD plus .