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Misidentification of Dementia in Medicare Claims and Related Costs
Zhu CW, Ornstein KA, Cosentino S, Gu Y, Andrews H, Stern Y.. Journal of the American Geriatrics Society, 2018-10-13
Topic: Risk, prevention and care in population studies
Plain-language summary
Objectives To examine how misidentification of dementia affects estimation of Medicare costs in a largely minority cohort of participants for whom accurate in-person diagnoses are available. Design Prospective cohort study. Setting Washington Heights-Inwood Columbia Aging Project, a multiethnic, population-based, prospective study of cognitive aging of Medicare beneficiaries aged 65 and older. Participants Individuals clinically diagnosed with dementia (n=495) and individuals clinically diagnosed without dementia (n=1,701). Measurements Medicare claims-identified dementia was defined according to the presence of any International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes for Alzheimer's disease and related dementias in all available claims during the study period. Participant characteristics associated with claims misidentification of dementia were estimated using logistic regression. Effects of dementia misidentification on Medicare expenditures were estimated using generalized linear models. Results Medicare claims correctly identified 250 of the 495 (51%) dementia cases and 1,565 of the 1,701 (92%) nondementia cases. Sensitivity of claims-identified dementia was 0.51, and specificity was 0.92. Average annual Medicare expenditures were $14,721 for a beneficiary with a clinical diagnosis of dementia, and $18,208 for a beneficiary with claim-identified dementia, suggesting an overestimation of $3,487 per person per year when Medicare claims were used to identify dementia. Total annual expenditures for all beneficiaries with claims-identified dementia were $258,707 lower than that for all those who were clinically diagnosed, suggesting an overall underestimation of total Medicare expenditures if Medicare claims were used to identify dementia. Different types of misidentification have different effects on dementia-related cost estimates. Average annual expenditures per person were highest for false positives. Conclusion Misidentification of dementia in Medicare claims is common. Using claims to identify dementia may result in significantly biased estimates of the cost of dementia. J Am Geriatr Soc 67:269-276, 2019.
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
APA 7th
Zhu, C. W., Ornstein, K. A., Cosentino, S., Gu, Y., Andrews, H., & Stern, Y. (2019). Misidentification of Dementia in Medicare Claims and Related Costs. Journal of the American Geriatrics Society. https://doi.org/10.1111/jgs.15638
Vancouver
Zhu CW, Ornstein KA, Cosentino S, Gu Y, Andrews H, Stern Y. Misidentification of Dementia in Medicare Claims and Related Costs. Journal of the American Geriatrics Society. 2019. doi:10.1111/jgs.15638. PMID: 30315744.
BibTeX
@article{zhu2019-30315744,
author = {Zhu, C. W. and Ornstein, K. A. and Cosentino, S. and Gu, Y. and Andrews, H. and Stern, Y.},
title = {{Misidentification of Dementia in Medicare Claims and Related Costs}},
journal = {Journal of the American Geriatrics Society},
year = {2019},
doi = {10.1111/jgs.15638},
pmid = {30315744},
url = {https://doi.org/10.1111/jgs.15638}
}
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Key findings
- Participant characteristics associated with claims misidentification of dementia were estimated using logistic regression.
- Results Medicare claims correctly identified 250 of the 495 (51%) dementia cases and 1,565 of the 1,701 (92%) nondementia cases.
- Total annual expenditures for all beneficiaries with claims-identified dementia were $258,707 lower than that for all those who were clinically diagnosed, suggesting an overall underestimation of total Medicare expenditures if Medicare claims were used to identify dementia.
- Using claims to identify dementia may result in significantly biased estimates of the cost of dementia.
Why it matters
Medicare claims correctly identified only 51% of clinically diagnosed dementia cases, and total annual expenditures for beneficiaries with claims-identified dementia were $258,707 lower than for those clinically diagnosed. This concerns how dementia is recorded in claims and how that affects cost estimates, not treatment, cure, or prevention.
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Study details
- Study designcohort study
- Participants495
- Evidence strengthModerate
How this study scored 61/100
Published in a peer-reviewed journal, and it is a cohort study following people over time. Scored zero for effect reported and randomized / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Journal of the American Geriatrics Society) |
| Journal's citation record | 3 / 4 | Journal of the American Geriatrics Society: journal h-index 344 (OpenAlex, 2026-10-29) |
| Study design | 7 / 12 | A cohort study following people over time |
| 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 | 2 / 5 | 2019 — within 10 year(s) of the newest study here |
| Sample size | 2 / 4 | 495 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 | 4 / 7 | Cited 75 times (OpenAlex, 2026-10-10) |
| Citations per year | 3 / 5 | 8.3 citations a year over 9 year(s) since 2019 |
| Impact for its field and year | 3 / 6 | Cited 6.8× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 2 / 6 | Cited by 8 other studies in this library |
| Still being cited | 2 / 4 | Cited 20 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 4 / 4 | Last-listed author Yaakov Stern: h-index 162 (OpenAlex, whole career) |
| Institution's track record | 2 / 3 | Columbia University: institution h-index 1,824 (OpenAlex) |
| Multicenter collaboration | 2 / 3 | OpenAlex lists 4 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 30315744) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 61 / 100 | — |
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