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Clock completion: an objective screening test for dementia
Watson YI, Arfken CL, Birge SJ.. Journal of the American Geriatrics Society, 1993-11-01
Topic: Brain imaging, connectivity and assessment
Objective To develop a simple, readily administered and scored screening test for dementia utilizing the clock-drawing task. Design Retrospective analysis of clock-drawing errors and prospective validations. Setting Hospital-based outpatient geriatric assessment clinic, rehabilitation service, apartment building for older adults, and long-term care facility. Participants Convenience sample of patients attending the geriatric assessment clinic, patients on the rehabilitation service, or residents of the above sites. Measurements Sensitivity and specificity of a clock-scoring system in identifying patients with dementia and the comparison of this system with the Short Blessed Test (SBT) in the diagnosis of dementia and in the prospective validation of the test. Results Of the 10 clock-drawing errors evaluated, placement of digits in a pre-drawn circle had the greatest sensitivity and specificity in distinguishing patients with irreversible dementia from patients with other disorders who did not meet NINCDS-ADRDA criteria for probable dementia. The derived scoring system had a sensitivity of 87% and a specificity of 82%, compared with a sensitivity of 82% and a specificity of 88% for the SBT in identifying dementia. Test-retest reliability for the distinction between demented and non-demented was 82%, with a Kappa of 0.63 for the clock completion, and 82%, with a Kappa of 0.62 for the SBT. Inter-rater reliability for clock completion was 0.90 to 0.93. Conclusion A simple, completely objective scoring system for a clock completion test has been developed which involves only the number of digits placed in the fourth quadrant of a pre-drawn circle. This readily administered test is as effective in screening for dementia as the longer six-item SBT.
Key findings
- Results Of the 10 clock-drawing errors evaluated, placement of digits in a pre-drawn circle had the greatest sensitivity and specificity in distinguishing patients with irreversible dementia from patients with other disorders who did not meet NINCDS-ADRDA criteria for probable dementia.
- The derived scoring system had a sensitivity of 87% and a specificity of 82%, compared with a sensitivity of 82% and a specificity of 88% for the SBT in identifying dementia.
Study details
- Evidence strengthLow
How this study scored 36/100
Published in a peer-reviewed journal. Scored zero for study design, sample size, effect reported, studied in people and randomised / 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 multi-centre collaboration, so those were left out: it earned 21 of the 58 points we could judge it on, which is 36 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Journal of the American Geriatrics Society) |
| Journal's citation record | — / 4 | No journal record from OpenAlex — left out of this score |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 1 / 5 | Rated “low” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 1993 — older than 20 years, still counted |
| 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 | No randomisation 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 |
| Multi-centre collaboration | — / 3 | Institutions not listed — left out of this score |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 8227899) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Points | 21 / 58 | Scored on 11 of 20 parts. We have no data for the rest, so they are left out: 21 of the 58 points we could judge it on is 36 out of 100. |
| Total | 36 / 100 | — |
What each of these 20 components measures, and what this score is not →
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APA 7th
Watson, Y. I., Arfken, C. L., & Birge, S. J. (1993). Clock completion: an objective screening test for dementia. Journal of the American Geriatrics Society. https://doi.org/10.1111/j.1532-5415.1993.tb07308.x
Vancouver
Watson YI, Arfken CL, Birge SJ. Clock completion: an objective screening test for dementia. Journal of the American Geriatrics Society. 1993. doi:10.1111/j.1532-5415.1993.tb07308.x. PMID: 8227899.
BibTeX
@article{watson1993-8227899,
author = {Watson, Y. I. and Arfken, C. L. and Birge, S. J.},
title = {{Clock completion: an objective screening test for dementia}},
journal = {Journal of the American Geriatrics Society},
year = {1993},
doi = {10.1111/j.1532-5415.1993.tb07308.x},
pmid = {8227899},
url = {https://doi.org/10.1111/j.1532-5415.1993.tb07308.x}
}