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Subjective cognitive decline as a predictor of future cognitive decline: a systematic review
Parfenov VA, Zakharov VV, Kabaeva AR, Vakhnina NV.. Dementia & neuropsychologia, 2020-07-01
Topic: Risk, prevention and care in population studies
Over 44 million people suffer from dementia around the world. Researchers estimated that there will be 48.1 million people with dementia by 2020 and 90.3 million by 2040. In addition to dementia, mild cognitive impairment (MCI) and subjective cognitive decline (SCD) relate to cognitive impairment. It has been established that MCI precedes dementia, however the significance of SCD is still unclear. Recent studies suggest that SCD could be a risk factor for objective cognitive impairment. SCD is defined as а self-estimated decline in cognitive capacity in comparison to an individual's previous level of functioning, which cannot be determined by neuropsychological tests. Objectives To perform a systematic review of prospective longitudinal cohort studies that assessed the risk of MCI and dementia among people with SCD. Methods A search was carried out for all available peer-reviewed articles in English related to SCD in PubMed and PsychINFO databases from database initiation through January 2020. The keywords used for the search were 'subjective cognitive (or memory) impairment (or decline or complaints)'. Three authors separately determined the inclusion or exclusion of all articles retrieved for full-text evaluation. Results The chance of progression to dementia in the SCD group was 2.17 (95% confidence interval [95%CI] 1.53‒3.07; p Conclusions SCD might precede cognitive impairment, however, more detailed longitudinal studies should be conducted.
Key findings
- Recent studies suggest that SCD could be a risk factor for objective cognitive impairment.
- Results The chance of progression to dementia in the SCD group was 2.17 (95% confidence interval [95%CI] 1.53‒3.07; p Conclusions SCD might precede cognitive impairment, however, more detailed longitudinal studies should be conducted.
Why it matters
This systematic review found that people with subjective cognitive decline had a higher chance of progressing to dementia. The authors conclude more detailed longitudinal studies are needed, and no treatment or prevention is tested.
Study details
- Study designsystematic review
- Evidence strengthHigh
How this study scored 57/100
Published in a peer-reviewed journal, and it is a systematic review of all the studies on the question. Scored zero for sample size, effect reported and studied in people because the record does not state it. We have no data on senior author's track record, so that was left out: it earned 55 of the 96 points we could judge it on, which is 57 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Dementia & neuropsychologia) |
| Journal's citation record | 0 / 4 | Dementia & Neuropsychologia: journal h-index 58 (OpenAlex, 2026-10-29) |
| Study design | 12 / 12 | A systematic review of all the studies on the question |
| Strength of evidence | 5 / 5 | Rated “high” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 2 / 5 | 2020 — within 10 year(s) of the newest study here |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 0 / 3 | Not stated whether this was studied in people — scores zero (not stated in the record — scored 0) |
| Randomised / blinded | 0 / 2 | A review of other studies — randomisation is not credited here |
| Times cited | 5 / 7 | Cited 130 times (OpenAlex, 2026-10-10) |
| Citations per year | 3 / 5 | 16.2 citations a year over 8 year(s) since 2020 |
| Impact for its field and year | 2 / 6 | Cited 2.1× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 2 / 6 | Cited by 3 other studies in this library |
| Still being cited | 3 / 4 | Cited 92 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | — / 4 | OpenAlex's profile for last-listed author Natalya Vasilyevna Vakhnina holds only 4 work(s), too few to judge a track record — left out of this score |
| Institution's track record | 0 / 3 | Sechenov University: institution h-index 284 (OpenAlex) |
| Multi-centre collaboration | 0 / 3 | OpenAlex lists 1 institution(s) in 1 country — scores zero (affiliation lists can be incomplete) |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 32973979) |
| Free to read | 2 / 2 | Free to read |
| Points | 55 / 96 | Scored on 19 of 20 parts. We have no data for the rest, so they are left out: 55 of the 96 points we could judge it on is 57 out of 100. |
| Total | 57 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
- DOI: 10.1590/1980-57642020dn14-030007
- PubMed: 32973979
- Original source →
- Free full text: Dementia & Neuropsychologia →
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. Check the citation against the original before you use it.
APA 7th
Parfenov, V. A., Zakharov, V. V., Kabaeva, A. R., & Vakhnina, N. V. (2020). Subjective cognitive decline as a predictor of future cognitive decline: a systematic review. Dementia & neuropsychologia. https://doi.org/10.1590/1980-57642020dn14-030007
Vancouver
Parfenov VA, Zakharov VV, Kabaeva AR, Vakhnina NV. Subjective cognitive decline as a predictor of future cognitive decline: a systematic review. Dementia & neuropsychologia. 2020. doi:10.1590/1980-57642020dn14-030007. PMID: 32973979.
BibTeX
@article{parfenov2020-32973979,
author = {Parfenov, V. A. and Zakharov, V. V. and Kabaeva, A. R. and Vakhnina, N. V.},
title = {{Subjective cognitive decline as a predictor of future cognitive decline: a systematic review}},
journal = {Dementia \& neuropsychologia},
year = {2020},
doi = {10.1590/1980-57642020dn14-030007},
pmid = {32973979},
url = {https://doi.org/10.1590/1980-57642020dn14-030007}
}
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