The following advertisement is focused on LDL particle number (LDL-P) testing, a novel new screening method used for assessing LDL. Based on the study shown in the advertisement, initial levels of LDL-C and LDL-P were obtained in 5584 individuals and the cumulative incidence of cardiovascular events was tracked. Which of the following choices best identifies the study design used in the advertisement?
A)Case-control study
B)Cross-sectional study
C)Prospective cohort study
D)Randomized clinical trial
E)Retrospective cohort study

Question

The following advertisement is focused on LDL particle number (LDL-P) testing, a novel new screening method used for assessing LDL. Based on the study shown in the advertisement, initial levels of LDL-C and LDL-P were obtained in 5584 individuals and the cumulative incidence of cardiovascular events was tracked.  Which of the following choices best identifies the study design used in the advertisement?
A)Case-control study
B)Cross-sectional study
C)Prospective cohort study
D)Randomized clinical trial
E)Retrospective cohort study

Quizplus · Accepted Answer

Explanation: The advertisement describes a study consisting of 5584 individuals without pre-existing cardiovascular disease who were categorized into study groups based on their LDL-P and LDL-C levels. They were then monitored for 5 years to assess the incidence of cardiovascular events. This is consistent with a prospective cohort study. In a prospective cohort study, a group of subjects (ie, the cohort) is selected and their exposure status is determined (eg, low LDL or high LDL). The cohort is then followed for a certain period and observed for development of the outcome (eg, cardiovascular events). (Choice A) A case-control study is designed by selecting patients with a particular disease (cases) and patients without that disease (controls) and then retrospectively determining their exposure status. (Choice B) A cross-sectional study, also known as a prevalence study, is characterized by the simultaneous measurement of an exposure and outcome within a specific population. It is a "snapshot study" that frequently uses surveys, making it relatively inexpensive and easy to perform. (Choice D) A randomized clinical trial directly compares 2 or more treatments. The subjects are usually randomly assigned to a treatment group or control group and then monitored for development of the outcome of interest. (Choice E) In a retrospective cohort study, the exposure status is determined at a particular point in the past and patients are tracked retrospectively, typically through their medical records. Educational objective: Prospective cohort studies are organized by selecting a group of individuals (ie, the cohort), determining their exposure status, and then following them over time for development of the disease of interest.

The Following Advertisement Is Focused on LDL Particle Number (LDL-P)