Summary BBS2007 - Statictics

BBS2007: “Linear and Logistic regression and Repeated Measures Analysis”


Lecture 3

Repeated measures
analysis
Bjorn Winkens
Methodology and Statistics
Maastricht University



Methodology and Statistics | University of Maastricht © Bjorn Winkens 2021

, Content
• Examples of correlated data
– repeated measures
– clustering
• ‘Simple’ methods
– ignoring dependency (WRONG)
– creating independency
• ‘Advanced’ methods (random intercept model)
– accounting for dependency (PREFERRED)
2

, Examples of correlated data
• Repeated measures within same subject
– Left and right eye /arm /leg /…
– Baseline, after 3, 6, and 12 months (“growth curve”)
– Before treatment, directly after treatment (short term
effect), and 12 months after treatment (long term
effect)
BBS2007: focus on this kind of dependency

• Clustered data
– Patients within a physician/surgeon
– Pupils within a class within a school
3

, Example: grade vs study time
But each subject is measured
twice


 plotted line
ignores
dependency!
Because there are
more than
measurement per
subject

Conclusion?
4