Question

Jerry is studying the relationship between taking drug A and risk of Stroke. In his study 60 people took the drug and 40 did not. Of those who took the drug, 10 had a stroke. Of those who did not take the drug, 5 had a stroke. The study took place over 10 years. Please draw a 2 by 2 table that represents this information.

What is the AR? What is the CIR? What are the three criteria for identifying a confounder in your DAG?

Answer 1

  RELATIONSHIP BETWEEN DRUG A & RISK OF STROKE

2 BY 2 TABLE

	PATIENTS WHO DEVELOPED STROKE	PATIENTSWHO DIDN'T DEVELOP STROKE	TOTAL
PATIENTS WHO TOOK DRUG A	10	50	60
PATIENTS WHO DIDN'T TAKE DRUG A	05	35	40
		TOTAL SAMPLES	100

AR means Action Research

Confounding Variable: also known as a third variable or mediator variable, influences both the independent variable and dependent variable.Being unaware of or failing to control for confounding variables may cause the researcher to analyse the results incorrectly.

Three criteria for identifying a confounder in DAG are that

1. it should be proxy (indirect indicator) measure of a cause, in unexposed people.
2. It must be correlated (positively or negatively) with exposure in the study population.
3. Must not be an intermediate step in the casual pathway between exposure and disease.