Examkin

Question

Difficulty: MediumStudy Design

A hospital infection control committee is investigating an unusual cluster of central line-associated bloodstream infections (CLABSIs) in the medical intensive care unit. Over the last quarter, 15 patients developed the infection. To identify potential risk factors, the committee plans to compare the clinical records of these 15 patients against 60 randomly selected patients who had central lines in the same unit during the identical time frame but did not develop the infection. The investigators aim to evaluate various prior exposures, such as the type of sterile dressing used, the duration of catheterization, and the specific personnel performing the insertion. Based on this proposed methodology, which of the following statements are accurate? (Select all that apply)

  1. The appropriate statistical measure of association for this investigation is the odds ratio.Answer
  2. The study is particularly well-suited for evaluating multiple potential exposures simultaneously.Answer
  3. C
    Participants are initially categorized according to their exposure status to determine the subsequent development of the outcome.
  4. D
    This methodology allows investigators to directly calculate the absolute incidence of the bloodstream infections in the intensive care unit.
  5. E
    Performing a stratified analysis on the data will help the investigators differentiate between recall bias and observer bias.

Answer

The investigation uses a case-control design, which appropriately calculates an odds ratio and is well-suited for evaluating multiple simultaneous exposures.
The scenario describes a classic case-control study, as patients are selected based on their disease outcome (CLABSI versus no CLABSI) and their past exposures are subsequently analyzed. Case-control studies are highly advantageous for evaluating multiple potential exposures simultaneously, which is crucial during outbreak investigations. Furthermore, because researchers dictate the number of cases and controls, the true incidence cannot be determined; therefore, the odds ratio is the mathematical measure used to estimate the relative risk.

Step-by-Step Solution

1
Identify the study design described in the vignette.
The researchers are starting with patients who already have the disease (15 CLABSI cases) and comparing them to patients without the disease (60 controls) to look back at past exposures.
Recognizing the directionality of the study (disease to exposure) defines it as a case-control study.
2
Determine the fundamental characteristics and statistical outputs of a case-control study.
Case-control studies are optimal for rare diseases or outbreaks, can evaluate multiple exposures for one outcome, and use the odds ratio to estimate association.
Understanding the strengths and limitations of the identified study design allows for the evaluation of the given statements.
3
Evaluate each option based on case-control methodology.
The statements regarding the odds ratio and the ability to evaluate multiple exposures accurately reflect case-control design principles.
Cohort studies categorize by exposure and can measure incidence; stratification addresses confounding, not bias types.

Key Concept

Characteristics of Case-Control Studies
Rate this question

Topics

Study Design

More questions from this topic