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Using a newly validated algorithm to estimate prevalence and incidence of Alzheimer’s Disease and related dementias in Medicare claims
Ana Sofía Afonso, Krista Marie Schroeder, Huabo Wang, Sarah Grace, Adam Phipps, John Randall Sims. Alzheimer s & Dementia, 2023-12-01
Topic: Amyloid, tau and blood-test diagnosis
Abstract Background Few published studies have estimated the prevalence and incidence of Alzheimer’s disease (AD) and AD related dementias (ADRD) in the US Medicare population using fit‐for‐purpose claims algorithms. This study utilized a newly validated administrative claims algorithm for identifying ADRD, the “1‐year Bynum‐Standard ADRD algorithm”, adjusted for positive predictive value (PPV) and sensitivity, to estimate the 2019 annual prevalence and annual incidence of ADRD in US Medicare patients 65+ years of age. Methods This study utilized Medicare Part A and B claims (Fee‐For‐Service and Medicare Advantage) limited to patients with at least one 2019 medical encounter. The study’s source population was limited to those 65+ years of age with Medicare Part D coverage and 1‐year pre‐encounter continuous enrollment. Utilizing the 1‐year Bynum‐Standard ADRD claims algorithm, patients with ADRD were compiled. As the Brynum‐Standard algorithm includes AD as well as related dementias, a second AD cohort was built adapting the algorithm’s code list to include only specific AD diagnoses. Prevalence was calculated as a percent of the source population after adjustment for PPV and sensitivity of the algorithm. Incidence calculations required a 1‐year pre‐diagnosis exclusion period. Results From 53.9 million Medicare patients with at least one 2019 medical encounter, 33.3 million patients qualified for the source population. Of these patients, 2.7 million (8.0%) qualified as having ADRD using the 1‐year Bynum‐Standard algorithm and 0.86 million of these patients (32.2%) were newly diagnosed (incident). After adjusting for 31.3% sensitivity and 70.3% PPV of the algorithm the estimated 2019 annual prevalence and incidence of ADRD in the Medicare population aged 65 or older was 18% and 5.8% respectively. When limited to patients with specific AD diagnoses only, 1.0 million prevalent and 0.37 million incident patients were identified resulting in an annual adjusted prevalence and incidence of 6.9% and 2.5% respectively. Prevalence and incidence calculations including adjustments are provided in figure 1. Conclusion Using a fit‐for‐purpose validated algorithm, the 2019 annual prevalence and incidence of ADRD in the Medicare population aged 65+ with Part D enrollment was estimated to be 18% and 5.8% respectively.
Key findings
- Results From 53.9 million Medicare patients with at least one 2019 medical encounter, 33.3 million patients qualified for the source population.
Why it matters
This study used a validated claims algorithm to estimate 2019 prevalence and incidence of Alzheimer's disease and related dementias in the US Medicare population. It is a methods study for measuring how common dementia is, not a study of treating, curing or preventing it.
Study details
- Effect size8.0%; 32.2%; or 31.3
- Evidence strengthModerate
How this study scored 33/100
Published in a peer-reviewed journal. Scored zero for study design, sample size, studied in people and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Alzheimer s & Dementia) |
| Journal's citation record | 2 / 4 | Alzheimer s & Dementia: journal h-index 228 (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 | 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 | 3 / 5 | 2023 — within 6 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 | 2 / 3 | Effect reported as a number, without an interval or test |
| 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 | 0 / 7 | Cited 0 times (OpenAlex, 2026-10-10) |
| Citations per year | 0 / 5 | 0.0 citations a year over 5 year(s) since 2023 |
| Impact for its field and year | 0 / 6 | Cited 0.0× 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 | 0 / 4 | Cited 0 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 2 / 4 | Last-listed author John Randall Sims: h-index 41 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | Eli Lilly (United States): institution h-index 744 (OpenAlex) |
| Multi-centre collaboration | 0 / 3 | OpenAlex lists 1 institution(s) in 1 country — scores zero (affiliation lists can be incomplete) |
| Indexed in PubMed | 1 / 2 | Not in PubMed, but has a DOI |
| Free to read | 2 / 2 | Free to read |
| Total | 33 / 100 | — |
What each of these 20 components measures, and what this score is not →
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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. Check the citation against the original before you use it.
APA 7th
Afonso, A. S., Schroeder, K. M., Wang, H., Grace, S., Phipps, A., & Sims, J. R. (2023). Using a newly validated algorithm to estimate prevalence and incidence of Alzheimer’s Disease and related dementias in Medicare claims. Alzheimer s & Dementia. https://doi.org/10.1002/alz.073664
Vancouver
Afonso AS, Schroeder KM, Wang H, Grace S, Phipps A, Sims JR. Using a newly validated algorithm to estimate prevalence and incidence of Alzheimer’s Disease and related dementias in Medicare claims. Alzheimer s & Dementia. 2023. doi:10.1002/alz.073664.
BibTeX
@article{afonso2023-bd017ecc,
author = {Afonso, Ana Sofía and Schroeder, Krista Marie and Wang, Huabo and Grace, Sarah and Phipps, Adam and Sims, John Randall},
title = {{Using a newly validated algorithm to estimate prevalence and incidence of Alzheimer’s Disease and related dementias in Medicare claims}},
journal = {Alzheimer s \& Dementia},
year = {2023},
doi = {10.1002/alz.073664},
url = {https://doi.org/10.1002/alz.073664}
}