Question

alzheimers disease is marked by amyloid plaques and tau tangles, and new amyloid - clearing drugs can slow decline only after mild cognitive problems begin. drawing on decades of data from the population - based mayo clinic study of aging, researchers built a risk calculator that combines age, sex, apoe genotype (a common genetic risk marker), and brain amyloid pet findings (from amyloid - sensitive brain scans) to estimate an individuals chances of developing mild cognitive impairment or dementia over the next decade or across the lifespan. the tool shows that women and apoe e4 carriers face higher lifetime risk, and amyloid pet has the largest impact on predictions. although currently a research instrument, the calculator follows a model already familiar in preventive medicine: cholesterol - based heart risk scores that help clinicians decide when to start statins. its design suggests that ______
12
mark for review
which choice most logically completes the text?
a clinicians can already rely on amyloid pet findings alone to diagnose alzheimers in symptom - free individuals and predict exactly when each person will slip into mild cognitive impairment.
b these individualized risk estimates could eventually guide earlier, personalized decisions about starting anti - amyloid therapy or adopting preventive lifestyle changes long before noticeable memory and thinking problems arise.
c because it depends on pet scans and genetics, this calculator is likely to remain mainly a research tool rather than a practical guide for everyday decisions about when to intervene.
d long - term follow - up of community participants suggests that dementia is rarer than previously thought, so calculators based on these data will mostly downplay peoples chances of ever developing cognitive decline.

Explanation:

To solve this, we analyze the context: the risk calculator for Alzheimer's follows a preventive medicine model (like cholesterol - based heart risk scores for statins). Option A claims clinicians can already rely on amyloid PET alone to diagnose and predict, but the text says the calculator is currently a research instrument, so A is wrong. Option B fits: the calculator's design (following a preventive medicine model) suggests it could guide early, personalized decisions about therapy or lifestyle changes before symptoms, as the heart risk score model guides statin decisions. Option C contradicts the preventive medicine model analogy (heart risk scores are practical), so C is wrong. Option D introduces new info about dementia prevalence not in the text, so D is wrong.

Answer:

B. these individualized risk estimates could eventually guide earlier, personalized decisions about starting anti - amyloid therapy or adopting preventive lifestyle changes long before noticeable memory and thinking problems arise.