Announcing March BEMC Talk

Dear Berlin-area Epidemiological Methods Enthusiasts,

You are invited to our next BEMC Talk on Wednesday, March 6th. Also join us this week for the BEMC Journal Club! The paper is already posted online.

BEMC Talk: Wednesday, March 6th, 2019 @ 4pm

“Regression shrinkage: better answers to causal questions” – Maarten van Smeden, Leiden

  • Please register online:
  • Description: “In this lecture, I will discuss regression shrinkage in the context of causal epidemiologic research. Although regression shrinkage methods have predominantly been used in prediction research (i.e. not to answer causal questions) to avoid statistical overfitting, I will posit the view that some of these methods can also improve estimates of exposure-outcome relationships. In particular, I will illustrate how a simple-to-apply approach known as Firth’s correction removes an often overlooked estimation bias in conventional regression analyses such as logistic regression.
  • Location: Seminar room of the Neurology Clinic; Bonhoefferweg 3 entrance, 3rdfloor, Charité – Campus Mitte

Upcoming Berlin Epi Events:

  • February 20st– BEMC JClub – Paper posted online
  • March 6th– BEMC Talk  “Shrinkage for causal inference” – Maarten van Smeden, Leiden
  • March 20th – BEMC JClub – Paper posted online
  • April 3rd – BEMC Talk –”One Size Does Not Fit All: Teaching Introductory Epidemiology” –Pamela Rist, Boston
  • April 17th – BEMC JClub – Paper will be posted online in late February
  • May 8th– BEMC Talk – “Machine Learning for Population-Based Health Studies” – Christoph Lippert, Potsdam
  • May 15th – BEMC JClub – Paper will be posted online in late March
  • June 5th – BEMC Talk – “Cool applications in R for epidemiologists” – Jochen Kruppa, Berlin

Interested in other Institute of Public Health events? Visit our calendar to check out upcoming conferences & short courses!

Follow BEMC on Twitter and leave questions for our speakers: @BEMColloquium

Lars Andersen, Time-dependent propensity scores: an application

Dear BEMCers,

This month, we are sharing a summary prepared by a student earning credit for the BEMC together with a photo. Thanks to the student, who prefers to remain anonymous!

This past Wednesday, Lars Andersen from Aarhus, Denmark, lectured on the use of time-dependent propensity score matching to address changes of treatment and covariates over time at the BEMC. After giving a general outline, Andersen introduced the immortal time bias as well as the related concept of “resuscitation bias” and explained how the latter can be avoided using risk set matching. As time-variant confounding remains an issue in the analysis phase, Lars Andersen introduced time-dependent propensity score matching as a strategy to deal with such a challenge.

As a clinician, Andersen explained how the nature of his clinical field and research questions inform his methodological choices. To illustrate these methods, Andersen elaborated on one of his papers dealing with tracheal intubation during cardiac arrests. In the paper, the authors could demonstrate that intubation lowered the chance of survival in an analysis using time-dependent propensity score matching while the unadjusted analysis revealed the opposite.


See you in March!