A pediatrician is reviewing medical literature to determine if there is an association between prenatal exposure to a newly approved antiemetic medication and the development of biliary atresia in infants. Because biliary atresia is extremely rare, she finds a study that first identifies patients who have already been diagnosed with this hepatic condition. The authors then identified a comparable group of healthy infants without the condition. Finally, they reviewed both groups' maternal pharmacy records to compare the prior rates of antiemetic use during the first trimester. Which of the following best describes the epidemiological study design used by these authors?
- Case-control studyAnswer
- BRetrospective cohort study
- CCross-sectional study
- DProspective cohort study
- ERandomized controlled trial
Answer
Case-control study
The described study is observational and begins by grouping patients based on the presence or absence of the outcome (biliary atresia). After identifying these cases and controls, the researchers look backward in time (retrospectively) to determine the frequency of the exposure (antiemetic use) in both groups. This design is highly efficient for studying rare diseases and is the hallmark of a case-control study.
Step-by-Step Solution
Key Concept
Case-control studies are observational studies that begin by selecting individuals based on their disease status (cases vs. controls) and then look retrospectively to assess for prior exposures.