| Course | HS830 Advanced Health Issues and Trends |
|---|---|
| Unit | Unit 3 |
| Paper type | Evidence appraisal |
| Length | About 1,380 words, 7 pages double-spaced |
| Format | APA 7 student paper |
| School | Purdue University Global |
| Program | Doctor of Health Science (DHSc) |
| Updated | October 2026 |
Free sample paper for HS830 Unit 3
Fewer New Cases, More Diagnoses: A Unit 3 Evidence Appraisal of the Claim That Dementia Is Becoming Less Common
[Student Name]
Purdue University Global
HS830: Advanced Health Issues and Trends
Unit 3 Evidence Appraisal
[Instructor Name]
[Date]
The consultancy report and the health system are composite; the studies appraised are real and their figures are reported as published.
The Claim and the Decision It Supports
The report's central sentence is that "dementia is becoming less common in the United States, so demand for memory care beds will grow more slowly than older forecasts assumed." It is offered in support of one decision: reducing a planned 48-bed memory care wing to 32 beds. Three sources stand behind the sentence. The report cites the Framingham Heart Study for falling incidence, the Health and Retirement Study for falling prevalence, and its own tabulation of Medicare claims, which it mentions only in a footnote because it shows recorded dementia diagnoses rising. The appraisal asks four questions of each source in the same order: what the series counts, how a case is defined, whether that definition held steady across the period, and who sits in the denominator. Holding the order fixed is the method. It lets a reader see whether the three series are measuring one thing or three, which the report never asks.
Source One: The Framingham Cohort
What it counts. Satizabal et al. (2016) followed participants of the Framingham Heart Study and its offspring cohort aged 60 and older across four five-year epochs, beginning in the late 1970s and ending in the late 2000s. The series counts new cases of dementia, which is incidence, not the number of people living with it.
How a case is defined. Dementia was diagnosed through ongoing cognitive surveillance and review by a panel of at least one neurologist and one neuropsychologist, using criteria from the Diagnostic and Statistical Manual of the period. That is a demanding, clinically grounded definition, and it was applied by the same study team throughout.
Whether the definition held. Largely yes. The study applied consistent review procedures across epochs, which is its great strength. The age- and sex-adjusted five-year incidence fell from 3.6 per 100 persons in the first epoch to 2.8, 2.2 and 2.0 per 100 in the later epochs, a decline of about 44 percent from first to last (Satizabal et al., 2016).
Who is in the denominator. Framingham participants are overwhelmingly white residents of one Massachusetts town and their offspring, and they became better educated over the decades. The decline appeared only among participants with at least a high school diploma. A pooled analysis of several cohorts in Europe and the United States found a similar pattern, an incidence decline of about 13 percent per decade, but those cohorts share Framingham's limitation of mostly white, relatively advantaged samples (Wolters et al., 2020).
Framingham shows that the risk of developing dementia at a given age fell for a particular population; it says nothing directly about how many people will need a memory care bed.
Source Two: The Health and Retirement Study
What it counts. Langa et al. (2017) compared dementia prevalence among adults 65 and older in two nationally representative waves of the Health and Retirement Study, 2000 and 2012. This is prevalence, the share of the population living with dementia at a point in time.
How a case is defined. Respondents were not examined by clinicians. Dementia was classified from a cognitive test battery administered in the survey, with proxy interviews for those unable to respond, using a scoring method validated against a clinically assessed subsample. The method is well established, but it classifies rather than diagnoses.
Whether the definition held. The same classification method was applied to both waves, so the comparison is internally consistent. Prevalence fell from 11.6 percent in 2000 to 8.8 percent in 2012, and greater educational attainment explained part of the decline (Langa et al., 2017). A later analysis using the same survey through 2016 reported a fall from 12.2 percent to 8.5 percent over sixteen years, with declines across groups but persistent gaps by race, ethnicity and education (Hudomiet et al., 2022).
Who is in the denominator. The survey samples community-dwelling and institutionalized older adults across the country and weights them to represent the national population. It is the strongest national source of the three. Its weakness for this decision is that a falling share is not a falling count. A smaller share of a much larger older population can still mean more people.
Source Three: The Report's Claims Tabulation
What it counts. The consultancy tabulated Medicare fee-for-service beneficiaries with a dementia diagnosis code on at least one claim in a year. This counts recorded diagnoses among people who used services and were coded.
How a case is defined. By billing codes entered by clinicians and coders, not by any standard assessment. A person with dementia who never receives a diagnosis is not counted, and a person given a code after a single visit for confusion is.
Whether the definition held. No. Over the period the report covers, awareness campaigns, the Medicare annual wellness visit with its cognitive assessment requirement and changes in coding practice all raised the chance that dementia would be recorded. Rising diagnoses in claims are therefore exactly what improved detection would produce even if true prevalence fell.
Who is in the denominator. Fee-for-service beneficiaries only, a group that has shrunk as a share of Medicare as enrollment in Medicare Advantage grew, and that differs in health and income from those who left it. The denominator moved during the series.
Why the Three Series Can Disagree Without Contradiction
Incidence, prevalence and recorded diagnosis can move in different directions at once. Incidence can fall while prevalence holds, if people with dementia now live longer after onset. Prevalence can fall while recorded diagnoses climb, if a larger share of existing cases is detected and coded. The report treats the three as one trend and then sets the claims data aside as an anomaly. A better reading is that they agree: the risk of developing dementia at a given age has fallen in some groups, the share of older adults living with it has fallen nationally, and the health system is recording more of the cases that exist.
Verdict on the Claim
The claim splits along the line the evidence draws. The statement that age-specific risk of dementia has fallen for some cohorts is supported by consistent cohort and survey evidence, with the caveat that the strongest evidence comes from mostly white, educated samples. The statement that the number of people needing memory care will shrink is not supported. Clinical Alzheimer's disease among adults 65 and over in the United States was estimated to affect about six million people in 2020, a count projected to more than double by 2060 as the population ages, even under assumptions that build in falling age-specific risk (Rajan et al., 2021). A falling rate applied to a rapidly growing older population still produces a rising count.
Implications for the Memory Care Decision
The board should not reduce the wing on the strength of this report. The appropriate input for a bed decision is a projected count of residents with moderate to severe dementia in the system's service area, built from local population projections and age-specific prevalence, not a national rate trend. If that projection, run with the lower post-2000 rates, still supports 48 beds, the wing should proceed as planned. If it supports fewer, the case for a smaller wing will rest on local demand rather than a misread national trend. Either way, the claims series has a use the report missed: rising diagnoses mean more families will arrive already knowing the diagnosis and asking for placement, which argues for planning intake capacity alongside beds.
Limits of This Appraisal
The appraisal relies on published summaries of each study's methods and did not reanalyze any data. The claims tabulation is described from the report, which did not release its code lists. Evidence on incidence trends among Black and Hispanic older adults, who carry a higher burden of dementia, is thinner than for white adults, and a local projection should test how sensitive its bed estimate is to that uncertainty.
References
Hudomiet, P., Hurd, M. D., & Rohwedder, S. (2022). Trends in inequalities in the prevalence of dementia in the United States. Proceedings of the National Academy of Sciences, 119(46), e2212205119. https://doi.org/10.1073/pnas.2212205119
Langa, K. M., Larson, E. B., Crimmins, E. M., Faul, J. D., Levine, D. A., Kabeto, M. U., & Weir, D. R. (2017). A comparison of the prevalence of dementia in the United States in 2000 and 2012. JAMA Internal Medicine, 177(1), 51-58. https://doi.org/10.1001/jamainternmed.2016.6807
Rajan, K. B., Weuve, J., Barnes, L. L., McAninch, E. A., Wilson, R. S., & Evans, D. A. (2021). Population estimate of people with clinical Alzheimer's disease and mild cognitive impairment in the United States (2020-2060). Alzheimer's & Dementia, 17(12), 1966-1975. https://doi.org/10.1002/alz.12362
Satizabal, C. L., Beiser, A. S., Chouraki, V., Chêne, G., Dufouil, C., & Seshadri, S. (2016). Incidence of dementia over three decades in the Framingham Heart Study. New England Journal of Medicine, 374(6), 523-532. https://doi.org/10.1056/NEJMoa1504327
Wolters, F. J., Chibnik, L. B., Waziry, R., Anderson, R., Berr, C., Beiser, A., Bis, J. C., Blacker, D., Bos, D., Brayne, C., Dartigues, J.-F., Darweesh, S. K. L., Davis-Plourde, K. L., de Wolf, F., Debette, S., Dufouil, C., Fornage, M., Goudsmit, J., Grasset, L., ... Hofman, A. (2020). Twenty-seven-year time trends in dementia incidence in Europe and the United States: The Alzheimer Cohorts Consortium. Neurology, 95(5), e519-e531. https://doi.org/10.1212/WNL.0000000000010022
The Purdue Global HS830 Unit 3 instructions
This unit usually calls for a critical appraisal of the evidence behind a claim about a health trend, often a claim found in a report, news article or policy brief. Expect five to seven pages in APA format. The appraisal should restate the claim and the decision it supports, then examine each source's design, case definition, consistency over time and population. Many prompts ask learners to explain how sources that seem to disagree may in fact be measuring different things. A verdict is expected, and the strongest ones split a claim into the parts the evidence supports and the parts it does not. A short section on implications for the decision and the appraisal's own limits usually completes the paper.
How the HS 830 Unit 3 example is put together
The paper restates the report's sentence and the bed decision it supports. Each source then receives four labeled paragraphs: what it counts, how a case is defined, whether the definition held and who is in the denominator. Framingham's panel-confirmed diagnoses and mostly white, educated cohort are weighed, along with a pooled analysis of several cohorts finding a decline of about 13 percent per decade. The survey's cognitive classification method and national sampling are next, followed by a later analysis showing prevalence falling to 8.5 percent by 2016. The claims series is judged unstable because detection and coding changed. A section explains why the three can disagree, and the verdict cites projections that cases will more than double by 2060.
Where the points sit in the HS830 Unit 3 rubric
Appraisal rubrics generally weight the critical analysis of sources most heavily, followed by the synthesis across sources, the soundness of the conclusion, the use of evidence and APA style. Analysis points depend on engaging with each study's methods rather than its abstract; case definition and population are where most marks are won or lost. Synthesis rewards explaining how different measures relate, such as incidence, prevalence and recorded diagnosis. Conclusions earn credit when they are as narrow as the evidence allows and tied back to the original decision. Applying the same standard to sources that support and oppose the claim often separates top papers from the rest. Reference accuracy and matching in-text citations make up the remaining points.
HS830 Unit 3 help from the desk
The common error is summarizing what each study found without asking how it defined a case, which hides why the sources diverge. Another is treating a falling rate as a falling count, ignoring population aging. Some appraisals dismiss inconvenient data, such as rising diagnoses, instead of explaining them. Verdicts that simply accept or reject the claim usually lose points for nuance. Papers that never return to the decision at stake read as literature reviews. If the claim you were assigned concerns a different condition, perhaps diabetes or heart failure, send the report or article, and an appraisal can be prepared that applies the same four questions to your sources. Leaving out the cohort's demographic makeup is another frequent omission that graders flag.
Get an HS830 Unit 3 example written to your instructions
Appraisal prompts usually name the claim, and sometimes the sources as well. Forward the prompt and rubric, plus the report or article if one was assigned; each series then gets tested for what it counts, how cases are defined and whether that definition held steady over the period. First custom samples are free. Expect yours inside 24-48h. The paper above is an original model document written by our desk, not a submitted student paper and not an official Purdue University Global document.
More HS830 papers and DHSc samples
- HS830 Unit 1: Vendor Concentration Discussion Post
- HS830 Unit 2: Pediatric Issue Scan With Four Tests
- HS830 Unit 4: Trend Data Analysis
- HS830 Unit 5: Seminar Reflection
- HS830 Unit 6: Counterargument Memo
- HS830 Unit 7: Horizon Scanning Report
- HS830 Unit 8: Implications Briefing
- HS830 Unit 9: Position Paper
- HS830 Unit 10: Emerging Issue Analysis
- HS820 Unit 3: Dutch and Swiss Comparative Matrix
- HS810 Unit 3: Stakeholder Power Map
HS830 Unit 3 questions, answered
What is the difference between incidence and prevalence here?
Incidence counts new cases arising in a population over a period; prevalence counts everyone living with the condition at a point in time. They can diverge: longer survival raises prevalence even when new cases fall. The sample keeps the terms separate because the composite report used them interchangeably, and that single slippage carried most of its argument.
Do I need to read the original studies?
Yes, at least their methods sections. Summaries of the Framingham and HRS findings often drop how cases were defined, and that definition is the whole appraisal. Library access usually covers the journals involved. Where a source sits behind a paywall you cannot reach, say what you read instead and limit the judgment accordingly.
Can an appraisal conclude that a claim is partly right?
It usually should. Evidence rarely supports or refutes a trend claim entirely, and doctoral rubrics reward splitting the claim along the line the evidence draws. The sample accepts that age-specific risk has fallen in some cohorts and rejects the inference that caseloads will shrink. Stating both, with the reason for each, is stronger than a single verdict.
Where can I find a free HS830 Unit 3 sample paper?
The complete Unit 3 evidence appraisal is posted here, testing whether dementia is becoming less common across three series with a split verdict and margin notes.
Should the hospital shrink its memory care wing?
Not on this report's evidence. The paper recommends a local projection of residents with moderate to severe dementia, since a falling national rate can coexist with a rising local count.