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62/100

✓ Peer-reviewed alzhub usefulness score 62 out of 100. Risk factors

Topic: Brain imaging, connectivity and assessment

Plain-language summary

The development of Alzheimer's disease (AD) later in life may be reflective of environmental factors operating over the course of a lifetime. Educational and occupational attainments have been found to be protective against the development of the disease but participation in activities has received little attention. In a case-control study, we collected questionnaire data about 26 nonoccupational activities from ages 20 to 60. Participants included 193 people with probable or possible AD and 358 healthy control-group members. Activity patterns for intellectual, passive, and physical activities were classified by using an adaptation of a published scale in terms of "diversity" (total number of activities), "intensity" (hours per month), and "percentage intensity" (percentage of total activity hours devoted to each activity category). The control group was more active during midlife than the case group was for all three activity categories, even after controlling for age, gender, income adequacy, and education. The odds ratio for AD in those performing less than the mean value of activities was 3.85 (95% confidence interval: 2.65-5.58, P < 0.001). The increase in time devoted to intellectual activities from early adulthood (20-39) to middle adulthood (40-60) was associated with a significant decrease in the probability of membership in the case group. We conclude that diversity of activities and intensity of intellectual activities were reduced in patients with AD as compared with the control group. These findings may be because inactivity is a risk factor for the disease or because inactivity is a reflection of very early subclinical effects of the disease, or both.

Cite this study APA, Vancouver, BibTeX · download .bib or .ris

APA 7th

Friedland, R. P., Fritsch, T., Smyth, K. A., Koss, E., Lerner, A. J., Chen, C. H., et al. (2001). Patients with Alzheimer's disease have reduced activities in midlife compared with healthy control-group members. Proceedings of the National Academy of Sciences. https://doi.org/10.1073/pnas.061002998

Vancouver

Friedland RP, Fritsch T, Smyth KA, Koss E, Lerner AJ, Chen CH, et al. Patients with Alzheimer's disease have reduced activities in midlife compared with healthy control-group members. Proceedings of the National Academy of Sciences. 2001. doi:10.1073/pnas.061002998. PMID: 11248097.

BibTeX

@article{friedland2001-11248097,
  author  = {Friedland, Robert Paul and Fritsch, Thomas and Smyth, Kathleen A. and Koss, Elisabeth and Lerner, Alan Jay and Chen, Chien Hsiun and Petot, Grace J. and Debanne, Sara M.},
  title   = {{Patients with Alzheimer's disease have reduced activities in midlife compared with healthy control-group members}},
  journal = {Proceedings of the National Academy of Sciences},
  year    = {2001},
  doi     = {10.1073/pnas.061002998},
  pmid    = {11248097},
  url     = {https://doi.org/10.1073/pnas.061002998}
}

Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. The record names 8 authors; APA and Vancouver show the first six, BibTeX and the downloads carry all of them. Check the citation against the original before you use it.

How to read this study

Design: this is a case-control study. People with the condition are compared with people without it, looking backward at past exposures. Recall of the past can be uneven between the groups, and the design shows association, not cause.
Size: the record lists 193 participants. Ask whether that is enough for the question, and who they were.
Effect: the record gives no effect size, so the summary above cannot say how large any difference was.

What the evidence grade means here

This page is graded moderate. alzhub.org assigns the grade automatically from keywords in the abstract, not from reading the paper. Moderate means the abstract mentions a cohort, case-control or longitudinal design. It can add at most 5 of the 100 points in the study score, and it is a label about design, not a verdict on whether the findings are true.

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Key findings

The increase in time devoted to intellectual activities from early adulthood (20-39) to middle adulthood (40-60) was associated with a significant decrease in the probability of membership in the case group.
We conclude that diversity of activities and intensity of intellectual activities were reduced in patients with AD as compared with the control group.
These findings may be because inactivity is a risk factor for the disease or because inactivity is a reflection of very early subclinical effects of the disease, or both.

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Study details

Study designcase-control study
Participants193
Evidence strengthModerate

How this study scored 62/100

Published in a peer-reviewed journal, and it is a case-control study. Scored zero for effect reported and randomized / blinded because the record does not state it. We have no data on journal's citation record, times cited, citations per year, impact for its field and year, cited by studies here, still being cited, senior author's track record, institution's track record and multicenter collaboration, so those were left out: it earned 36 of the 58 points we could judge it on, which is 62 out of 100.

Component	Points	Why
Journal tier	7 / 10	Tier 3 — peer-reviewed journal (Proceedings of the National Academy of Sciences)
Journal's citation record	— / 4	No journal record from OpenAlex — left out of this score
Study design	6 / 12	A case-control study
Strength of evidence	3 / 5	Rated “moderate” in our summary
Peer-review validation	10 / 10	Peer-reviewed. Published as an article in a named peer-reviewed journal.
How recent	1 / 5	2001 — older than 20 years, still counted
Sample size	2 / 4	193 participants
Effect reported	0 / 3	No effect size reported — scores zero (not stated in the record — scored 0)
Studied in people	3 / 3	Studied in people (participant count stated)
Randomized / blinded	0 / 2	No randomization or blinding stated — scores zero (not stated in the record — scored 0)
Times cited	— / 7	No citation count (not found in OpenAlex) — left out of this score
Citations per year	— / 5	No citation count or no year — left out of this score
Impact for its field and year	— / 6	No field-weighted citation impact (OpenAlex has none yet) — left out of this score
Cited by studies here	— / 6	Not yet checked against this library's citation graph — left out of this score
Still being cited	— / 4	No yearly citation counts — left out of this score
Senior author's track record	— / 4	Senior author's record not available — left out of this score
Institution's track record	— / 3	No institution listed in OpenAlex — left out of this score
Multicenter collaboration	— / 3	Institutions not listed — left out of this score
Indexed in PubMed	2 / 2	Indexed in PubMed (PMID 11248097)
Free to read	2 / 2	Free to read
Points	36 / 58	Scored on 11 of 20 parts. We have no data for the rest, so they are left out: 36 of the 58 points we could judge it on is 62 out of 100.
Total	62 / 100	—

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