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Zorluk: KolayEpidemiologic Study Designs

A public health physician is investigating an outbreak of acute gastroenteritis following a large community picnic. To determine the source of the outbreak, the physician identifies 50 individuals who developed gastroenteritis symptoms within 48 hours of the event. The physician then identifies 100 individuals who attended the picnic but did not develop any symptoms. Both groups are interviewed about the specific foods they consumed at the picnic. Which of the following best describes the epidemiologic study design used in this investigation?

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

Cevap

Case-control study
The study describes grouping subjects based on their outcome status (those with acute gastroenteritis versus those without) and then retrospectively assessing their exposure (foods consumed at the picnic). This is the hallmark of a case-control study, which is frequently used to quickly investigate outbreaks.

Adım Adım Çözüm

1
Identify how the subjects were initially selected or grouped by the investigator.
The physician specifically selected 50 individuals with the outcome (gastroenteritis) and 100 individuals without the outcome.
Understanding the grouping mechanism is the primary step in identifying an observational study design.
2
Determine the timing of the exposure assessment relative to the grouping.
After being grouped by their disease status, both groups were asked to recall their past food consumption.
Looking backward in time for an exposure after grouping subjects by outcome is the defining characteristic of a specific study type.
3
Classify the study design based on these specific characteristics.
Grouping by outcome and looking retrospectively at exposure characterizes a case-control study.
This precisely matches the classic definition and typical application of a case-control design.

Anahtar Kavram

In a case-control study, subjects are selected based on the presence (cases) or absence (controls) of a disease, and their previous exposure status is then assessed and compared.
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Epidemiologic Study Designs

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