Question

Which method is being used to control for confounding by smoking in each of the studies below?

1. A cohort study of the effect of a new lipid-lowering medication on the incidence of CHD that is limited to non-smokers ≥50 years of age.

Options: Is this Restriction, matching, stratified analysis, randomization or mediation?

Briefly justify why you chose this option?

Answer 1

Stratified analysis
cohort study with new statin lipid-lowering mediation in stroke and CHD with non-smokers and no history of vascular events estimates the effects of the drug within the cause of disease.
Stratified analysis by the person, sex, age, BMI, lipid profile, hypertension, systolic blood pressure that design for improving the efficiency of analysis proceeding with potential confounders in cohort study have the same distribution by strata defined.
The matching method avoids confounding in the study design. cohort studies are observational studies. A randomized study that investigates interventional medicine that not useful for testing causes of disease. randomization controls minimize bias and confounding.