Match each epidemiological study scenario to the most appropriate measure of disease frequency or association it is designed to calculate.
- Researchers select 500 patients with biopsy-proven pancreatic cancer and 500 age-matched patients admitted for orthopedic trauma, then review their medical records for a history of chronic pancreatitis.Odds ratio (ratio of the odds of exposure among cases to the odds of exposure among controls)
- A health department screens 10,000 residents over a one-week period to assess the total burden of active tuberculosis in the community in order to allocate appropriate healthcare resources.Point prevalence (proportion of the population with the condition at a specific time)
- A multicenter study enrolls 5,000 adults without cardiovascular disease, categorizes them based on their daily sodium intake, and tracks them for 10 years to compare the rate of new-onset myocardial infarction.Relative risk (ratio of the incidence of disease among exposed to the incidence among unexposed)
- A double-blind study randomizes patients with heart failure to receive either standard therapy or a novel beta-blocker, subsequently determining the number of individuals who must be prescribed the new medication to prevent one hospitalization.Number needed to treat (inverse of the absolute risk reduction)
Cevap
The case-control study maps to the odds ratio. The cross-sectional screening maps to point prevalence. The prospective cohort study maps to relative risk. The randomized controlled trial for intervention benefit maps to the number needed to treat.
Matching these study designs to their respective epidemiological measures requires an understanding of how subjects are sampled and what temporal relationships are assessed. Case-control studies (sampling by outcome) yield odds ratios. Cohort studies (sampling by exposure and following prospectively) yield true incidence rates and thus relative risks. Cross-sectional surveys measure disease burden at one snapshot in time, yielding prevalence. Clinical trials evaluating the benefit of an intervention often report its clinical utility via the number needed to treat.
Adım Adım Çözüm
Anahtar Kavram
The appropriate measure of disease frequency or association depends entirely on the underlying epidemiological study design and the method of subject sampling.