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.

lars_andersenbemc

See you in March!

Announcing February BEMC Talk

Dear Berlin-area Epidemiological Methods Enthusiasts,

Thank you for participating in our 2018 BEMC Talks! We will be taking a short break in January and look forwarding to seeing you again in February!

You are invited to our next BEMC Talk on Wednesday, February 6th.

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

“The use of time-depending propensity score matching to address changes of treatment and covariates over time” – Lars Andersen, Aarhus, Denmark

  • Please register online: https://goo.gl/forms/jKhS5kVGIR0fTvX03
  • Description: “Time-related biases, such as immortal time bias, are well-known within the epidemiology literature. However, they continue to be a problem in the published medical literature. The lecture will focus on time-related bias and how they can be effectively addressed using a combination of risk set matching and time-dependent propensity scores. Studies with cardiac arrest, where a specific type of time-related bias (“resuscitation time bias”) is a problem, will be used as examples.”
  • Location: Virchow-Saal, Philippstr. 11, Charité – Campus Mitte (this location is only for December 2018 and February 2019)

Upcoming Berlin Epi Events:

  • February 20th – BEMC JClub  – Paper posted online
  • March 6th – BEMC Talk  “Shrinkage for causal inference” Maarten van Smeden, Leiden
  • March 20th – BEMC JClub – Paper will be posted online in late January
  • April 3rd – BEMC Talk Pamela Rist, Boston
  • April 17th – BEMC JClub – Paper will be posted online in late February
  • Tuesday, May 7th – IPH Lecture (no BEMC Talk in May)– Frits Rosendaal from Leiden

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

End of 2018: wrap-up

A big thanks to all of our fantastic speakers and of course, our engaged Berlin-area epidemiology community for another great year of BEMC! Here a few impressions from the last several months. We just finalized our 2019 BEMC Talks line-up. Next year, we’re bringing in epi talent from Aarhus, Leiden, Boston, Berlin, Los Angeles, Vancouver, Toulouse, & Tirol. Check out the ‘Talks’ tab. Wishing you a relaxing last few days off and, of course, guten Rutsch!

-Jess, Magdalen, Bob & Tobias

Announcing December BEMC Talk

Dear Berlin-area Epidemiological Methods Enthusiasts,

You are invited to our next BEMC Talk on Wednesday, December 5th.

BEMC Talk: Wednesday, December 5th, 2018 @ 4pm

“This talk has no title” – James Robins, Boston

  • We have reached capacity for the lecture hall. Please understand our inability to accept walk-ins today.
  • Description: “Dr. Robins is the Mitchell L. and Robin LaFoley Dong Professor of Epidemiology at the Harvard TH Chan School of Public Health. He is a renowned epidemiologist and biostatistician, as well as an award-winning mentor. His contributions to quantitative methods helped define modern epidemiology. In addition to leading the movement to improve methods for causal inference in observational health research studies, Dr. Robins developed novel methods for evaluating time-varying exposures, including structural nested models and marginal structural models. His recent work has addressed diverse domains including higher order influence function estimators, identification of effects with instrumental variables, enhancing the validity of per-protocol analyses of trials, and integrating empirical and simulation studies. We offer no title for the talk because Dr. Robins’ public lectures are notoriously unpredictable, but they are reliably entertaining, provocative, and insightful.”
  • Location: Virchow-Saal, Philippstr. 11, Charité – Campus Mitte (this location is only for December)

Upcoming Berlin Epi Events:

  • Nov 14th @ 4pm – BEMC JClub  – Paper posted online
  • Dec 19th @ 4pm – BEMC JClub Cancelled. 
  • January – BEMC Events Cancelled. See you in February!
  • February 6th  – BEMC Talk  “Time-related biases and the use of propensity scores to address those” Lars Andersen, Copenhagen
  • Feb 14th @ 4pm – BEMC JClub  – Paper will be posted online in late January

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

Announcing November BEMC Talk

Dear Berlin-area Epidemiological Methods Enthusiasts,

You are invited to our next BEMC Talk on Wednesday, November 7th.

BEMC Talk: Wednesday, November 7th, 2018 @ 4pm

“Multi state modelling in chronic diseases” – Dr. Ralph Brinks, Düsseldorf

  • If you haven’t already done so, please register in advance: https://goo.gl/forms/sfxMmTOg51egpMeh2
  • Description: “Multi-state models are a useful extension of the epidemiologist’s toolbox. The classical illness-death model gains fundamental insights about relations between the prevalence and incidence of a chronic disease – insights beyond the folkloristic ‘prevalence odds equals incidence times duration’.  A variety of applications is presented, e.g. diabetes and rheumatic diseases in the study of dementia. With a simple extension, the illness-death model is helpful in studying diseases with a prolonged state of undiagnosed disease such as hypertension or cancer.
  • Location: Seminar room of the Neurology Clinic; Bonhoefferweg 3 entrance, 3rd floor, Charité – Campus Mitte

Upcoming Berlin Epi Events:

  • Nov 14th @ 4pm – BEMC JClub  – Paper posted online
  • December 5th – BEMC Talk – “This talk has to title” – Professor James Robins, Boston (location: Virchow-Saal, Philippstr. 12, Charite Campus Mitte)
  • Dec 19th @ 4pm – BEMC JClub Cancelled. 
  • January – Winter Break, no BEMC
  • February 6th – BEMC Talk – “Time-related biases and the use of propensity scores to address those” – Professor Lars Andersen, Copenhagen

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

Announcing October BEMC Talk

Dear Berlin-area Epidemiological Methods Enthusiasts,

You are invited to our next BEMC Talk on Wednesday, October 10th.

BEMC Talk: Wednesday, October 10th, 2018 @ 4pm

“Interactive DAGs: Exploring causality theory with Dagitty” – Dr. Johannes Textor (Nijmegen)

  • If you haven’t already done so, please register in advance: https://goo.gl/forms/nEchjAyHekh41o2u1
  • Description: “DAGs can be useful to aid causal interpretation of observational data, but sensibly applying DAGs in practice can be very challenging. The talk will discuss (1) how we can test whether a DAG is mis-specified or inconsistent with a dataset; (2) how we can deal with the issue of statistical equivalence between DAGs; and (3) how we can conduct DAG-based analyses when the presence of latent confounders cannot be ruled out. Hands-on examples will be given that use the website ‘dagitty.net’ and the accompanying R package.”
  • Location: Seminar room of the Neurology Clinic; Bonhoefferweg 3 entrance, 3rd floor, Charité – Campus Mitte

Upcoming Berlin Epi Events:

  • Oct 17th @ 4pm – no JClub. Join us at the IPH Lecture with Maria Glymour, ScD, MS, Professor at UCSF School of Medicine, as she presents “Are we ready for a biomarker-only based diagnostic criterion for research in Alzheimer’s Disease?”.
  • November 7th – BEMC Talk – “Multi state modelling in chronic diseases”  – Dr. Ralph Brinks, Düsseldorf
  • December 5th – BEMC Talk – Professor James Robins, Boston

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

Announcing September BEMC Talk

Dear Berlin-area Epidemiological Methods Enthusiasts,

You are invited to our next BEMC Talk on Wednesday, September 5th.

BEMC Talk: Wednesday, September 5th, 2018 @ 4pm

“Covariate selection in observational studies with limited knowledge of the true causal structure” – Dr. Sebastian Baumeister (Augsburg)

  • If you haven’t already done so, please register in advance: https://goo.gl/forms/MPnYT5NQVoeSKt3F3
  • Description: “Unconfoundedness is assumed to generate an unbiased estimate of a causal effect on an outcome. If there is sufficient knowledge on the underlying causal structure, established covariate selection criteria based on a causal directed acyclic graph (DAG) can be used to select subsets of observed pretreatment covariates. However, although variable selection approaches should be based on an understanding of the causal structure representing the common cause pathways between treatment and outcome, the true causal structure is rarely known. When knowledge of the causal structure is not sufficient for use of a DAG, alternative covariate selection strategies are needed. Common suggestions when the causal structure is only partially known include “all observed pretreatment covariates” (Rubin) or the “disjunctive cause criterion” (VanderWeele & Shpister). Data-driven procedures for selection of covariates have also been proposed (e.g., change-in-MSE, focused selection, CovSel). Defining subsets of covariates that are sufficient to control for confounding empirically is difficult in the absence of background knowledge on the causal data-generating mechanism because adjustment for covariates that are affected by the exposure or the outcome and adjustment for instruments can increase bias.”
  • Location: Seminar room of the Neurology Clinic; Bonhoefferweg 3 entrance, 3rd floor, Charité – Campus Mitte

Upcoming Berlin Epi Events:

  • Sept 19th @ 4pm – BEMC JClub  – Paper is posted online
  • October 10th – BEMC Talk “Interactive DAGs: Exploring causality theory with Dagitty” – Dr. Johannes Textor, Nijmegen 
  • Oct 17th @ 4pm – no JClub. Join us at the IPH Lecture with Maria Glymour, ScD, MS, Professor at UCSF School of Medicine, as she presents “Are we ready for a biomarker-only based diagnostic criterion for research in Alzheimer’s Disease?” Please register for the event: https://iph-lecture.eventbrite.de
  • November 7th – BEMC Talk – “Multi state modelling in chronic diseases”  – Dr. Ralph Brinks, Düsseldorf
  • December 5th – BEMC Talk – Professor James Robins, Boston

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

Summer Break! No BEMC Talk in August – see you in September.

Dear Berlin-area Epidemiological Methods Enthusiasts,

we hope you are enjoying a nice summer holiday, perhaps by a lake, the sea, or on a mountain.

As a reminder, we will not be having a BEMC Talk or Journal Club in August.

  • August – no BEMC Talk or JClub – Enjoy your summer break!
  • August 20-24th – IPH Intensive Short Course – “Advanced Epidemiologic Methods – causal research and prediction modeling” (Instructors: Rolf Groenwold/Maarten van Smeden)
  • September 5th – BEMC Talk – Prof Dr. Sebastian Baumeister, Regensburg
  • October 10th – BEMC Talk – “Interactive DAGs: Exploring causality theory with Dagitty” – Dr. Johannes Textor, Neijmigen
  • October 17th- no JClub. Join us at the IPH Lecture with Maria Glymour, ScD, MS, Professor at UCSF School of Medicine, as she presents “Are we ready for a biomarker-only based diagnostic criterion for research in Alzheimer’s Disease?”.

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

July 18th: Next BEMC JClub

Dear friends of the BEMC,

Please join us for one last journal club before the summer break.

We’ll be reading:

Hernán MA, Robins JM. Using Big Data to Emulate a Target Trial When a Randomized Trial Is Not Available. Am J Epidemiol. 2016 Apr 15;183(8):758–64.

We will meet next week Wednesday, July 18th at 4pm at our usual location (Click here for all details and to send in your questions/comments on the paper in advance).

See you there!

Here’s a picture from the July 4th BEMC Talk- thanks to all who joined us and to Prof. Rose for a great talk!

Image uploaded from iOS (1).jpg

Announcing July BEMC Talk

Dear Berlin-area Epidemiological Methods Enthusiasts,

You are invited to our next BEMC Talk on Wednesday, July 4th.

BEMC Talk: Wednesday, July 4th, 2018 @ 4pm

“Applications of computer adaptive testing and item response theory in health outcomes assessment” – Professor Matthias Rose (Berlin)

  • If you haven’t already done so, please register in advance: https://goo.gl/forms/uPEdQQlPePd9vffo2
  • Description: “With an increased life-expectancy, the challenges for modern medicine have changed significantly over the last decades. Acute diseases are declining in western societies whereas the number of patients with chronic diseases increases and more patients are suffering from multimorbid conditions. Thus, the need to reconsider the measurement of treatment success has emerged, and in particular how to include the patients’ perspective into routine health outcome assessments. The talk will present new psychometric methods for the measurement of Patient-Reported Outcomes (PRO) promising to provide more comparable, more precise and less burdensome assessment tools.”
  • Location: Seminar room of the Neurology Clinic; Bonhoefferweg 3 entrance, 3rd floor, Charité – Campus Mitte

Upcoming Berlin Epi Events:

  • August – no BEMC Talk or JClub – Enjoy your summer break!
  • August 20-24th – IPH Intensive Short Course – “Advanced Epidemiologic Methods – causal research and prediction modeling” (Instructors: Rolf Groenwold/Maarten van Smeden)
  • September 5th – BEMC Talk – Prof Dr. Sebastian Baumeister, Regensburg

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