Critical Thinking - Lecture Twenty-Eight

Question 1

Controlling confounding in the study analyses

Answer 1

Stratification
Multivariable Analysis
Standardisation

Question 2

Stratification

Answer 2

Calculating measure of association for each stratum of potential confounder and comparing them

Question 3

Stratification steps

Answer 3

1. Calculate the measure of association between exposure and outcome
2. Divide potential confounder into strata (levels)
3. For each stratum, calculate the measure of association between the exposure and outcome
4. Compare stratum-specific measures of association

Question 4

Strengths of stratification

Answer 4

Easy for small number of potential confounders with limited strata
Can evaluate impact of confounding
Can identify effect modification

Question 5

Limitations of stratification.

Answer 5

Can leave residual confounding

Not feasible when dealing with lots of potential confounders with many strata

Question 6

Multivariable analysis

Answer 6

Statistical method for estimating measure of association whilst controlling for multiple potential confounders

Question 7

Potential issues: controlling in study analyses

Answer 7

Residual confounding

Can only control what you’ve measured

Question 8

How much change indicates confounding?

Answer 8

10% or more

Question 9

Effect modification

Answer 9

The association between exposure and outcome differs across strata of the effect modifier