An investigator interested in the etiology of neonatal jaundice conducted a study where he selected...

In a case-control study, participants are selected based on outcome (e.g., presence or absence of neonatal jaundice), and then past exposures are evaluated. This is consistent with the described methodology.

Toronto Notes 2023 – Epidemiology, “Study Designs”:

“Case-control studies start with the outcome and look backward to assess exposures. They are efficient for studying rare conditions or those with long latency.”

MCCQE1 Objectives (Population Health > 65-2: Epidemiology and Study Design):

“Candidates must distinguish between common study designs and recognize the correct classification based on study structure.”

Cross-sectional studies (A) assess exposure and outcome at the same time. Cohort studies (C) begin with exposure and follow forward. Clinical trials (D) are interventional. Ecological studies (E) analyze population-level data.

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