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Validity and reliability of the Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change. The Alzheimer's Disease Cooperative Study
Lara Schneider, Jason T. Olin, Rachelle Smith Doody, Christopher M. Clark, John C. Morris, Barry Reisberg, Frederick A. Schmitt, Michael Grundman, Ronald G. Thomas, Steven H. Ferris. Alzheimer Disease & Associated Disorders, 1997
Topic: Amyloid, tau and blood-test diagnosis
This article reports the development and psychometric properties of the Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change (ADCS-CGIC). At present, a number of unvalidated CGIC scales are used in clinical trials, with various methods for making ratings. The ADCS-CGIC was designed on the basis of a survey of ADCS clinicians and by adapting existing instruments. It includes an organized but unstructured format, with which a clinician can address clinically relevant change. The instrument's reliability and validity were assessed in a prospective trial of Alzheimer's disease (AD) and healthy subjects over a 12-month period. It showed good short-term reliability at 1 and 2 months, with 90 and 94% of AD subjects, respectively, rated as having changed not at all or only minimally. The ADCS-CGIC's face validity was demonstrated by untreated. AD subjects rated as having worsened over time at both 6 months (56% rated as having worsened) and 12 months (81% rated as having worsened), whereas only 2% of control subjects showed minimal worsening. As a measure of predictive validity, ADCS-CGIC ratings at 12 months were significantly associated with change on four severity scales. As with other measures, change ratings were sensitive to dementia severity. Moderately impaired subjects showed greater worsening than other subjects. ADCS-CGIC ratings of greater worsening were made after the informant interview, regardless of whether informants or subjects were interviewed first. The ADCS-CGIC is a valid and reliable instrument for use in clinical trials.
Why it matters
Reports the development and testing of the ADCS-CGIC, a clinician rating of overall change designed for Alzheimer's clinical trials. At 12 months, 81% of untreated Alzheimer's participants were rated as worsened, while only 2% of controls showed minimal worsening, and the authors conclude it is valid and reliable for use in clinical trials.
How this study scored 44/100
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 strength of evidence, so that was left out: it earned 42 of the 95 points we could judge it on, which is 44 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Alzheimer Disease & Associated Disorders) |
| Journal's citation record | 1 / 4 | Alzheimer Disease & Associated Disorders: journal h-index 131 (OpenAlex, 2026-10-29) |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | — / 5 | No evidence rating recorded — left out of this score |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 1997 — 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 | 6 / 7 | Cited 649 times (OpenAlex, 2026-10-10) |
| Citations per year | 4 / 5 | 20.9 citations a year over 31 year(s) since 1997 |
| Impact for its field and year | 4 / 6 | Cited 11.8× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 0 / 6 | No other study in this library cites it |
| Still being cited | 2 / 4 | Cited 33 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 3 / 4 | Last-listed author Steven H. Ferris: h-index 91 (OpenAlex, whole career) |
| Institution's track record | 2 / 3 | University of Southern California: institution h-index 1,521 (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 9236949) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Points | 42 / 95 | Scored on 19 of 20 parts. We have no data for the rest, so they are left out: 42 of the 95 points we could judge it on is 44 out of 100. |
| Total | 44 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
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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. The record names 10 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.
APA 7th
Schneider, L., Olin, J. T., Doody, R. S., Clark, C. M., Morris, J. C., Reisberg, ., et al. (1997). Validity and reliability of the Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change. The Alzheimer's Disease Cooperative Study. Alzheimer Disease & Associated Disorders. https://doi.org/10.1097/00002093-199700112-00004
Vancouver
Schneider L, Olin JT, Doody RS, Clark CM, Morris JC, Reisberg , et al. Validity and reliability of the Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change. The Alzheimer's Disease Cooperative Study. Alzheimer Disease & Associated Disorders. 1997. doi:10.1097/00002093-199700112-00004. PMID: 9236949.
BibTeX
@article{schneider1997-9236949,
author = {Schneider, Lara and Olin, Jason T. and Doody, Rachelle Smith and Clark, Christopher M. and Morris, John C. and Reisberg, Barry and Schmitt, Frederick A. and Grundman, Michael and Thomas, Ronald G. and Ferris, Steven H.},
title = {{Validity and reliability of the Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change. The Alzheimer's Disease Cooperative Study}},
journal = {Alzheimer Disease \& Associated Disorders},
year = {1997},
doi = {10.1097/00002093-199700112-00004},
pmid = {9236949},
url = {https://doi.org/10.1097/00002093-199700112-00004}
}
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