Examkin

Soru

Zorluk: OrtaEpidemiologic Study Designs

A team of gastroenterology researchers is investigating potential pharmacological risk factors for microscopic colitis. The investigators review pathology records at a large tertiary care center to identify 150 patients who were diagnosed with microscopic colitis via colonoscopy between 2020 and 2025. As a comparison group, they select 300 patients who underwent colonoscopy for chronic diarrhea during the same timeframe but were found to have normal colonic mucosa. The researchers then review the electronic health records of all participants to determine the frequency and duration of proton pump inhibitor (PPI) use in the 12 months preceding their colonoscopies. Which of the following best describes the study design utilized in this investigation?

  1. Case-control studyCevap
  2. B
    Retrospective cohort study
  3. C
    Cross-sectional study
  4. D
    Prospective cohort study
  5. E
    Nested case-control study

Cevap

Case-control study
The correct answer accurately identifies that the researchers grouped participants based on disease status (microscopic colitis cases versus normal mucosa controls) and then looked back in time to assess past exposure to proton pump inhibitors. This outcome-to-exposure methodology is the hallmark of a case-control study.

Adım Adım Çözüm

1
Analyze how the researchers selected the initial study groups.
Participants were selected based on whether they had microscopic colitis (the outcome) or normal colonic mucosa (lack of the outcome).
Identifying the basis of group selection is the primary step in determining an epidemiologic study design.
2
Determine the temporal direction of the investigation.
After selecting groups based on the outcome, the researchers looked backward into the electronic health records to determine past PPI use (the exposure).
The temporal relationship between selection and data collection distinguishes case-control from cohort studies.
3
Combine the selection criteria and temporal direction to identify the specific design.
Selecting by outcome and looking back for exposure defines a case-control study.
This precisely matches the methodology described in the clinical vignette.

Anahtar Kavram

A case-control study identifies participants based on the presence or absence of a specific disease (outcome) and investigates past records or histories to determine the frequency of a suspected risk factor (exposure).
Bu soruyu puanla

Konular

Epidemiologic Study Designs

Bu konudan daha fazla soru