Publications

Effect heterogeneity and variable selection for standardizing causal effects to a target population

Published in European Journal of Epidemiology, 2019

In this paper we explain our thinking on the generalizability of randomized trials to a wider audience; and compare and contrast the COST parameters approach with two competing frameworks for external validity.

Recommended citation: Huitfeldt A, Swanson SA, Stensrud MJ, Suzuki E. "Effect heterogeneity and variable selection for standardizing causal effects to a target population". In press, European Journal of Epidemiology http://ahuitfeldt.github.io/files/paper6.pdf

On the collapsiblity of measures of effect in the counterfactual causal framework

Published in Emerging Themes in Epidemiology, 2019

Here, we provide a new weighting scheme for causal measures of effect. While this is a technical note containing only a minor new result (which is subsequently used in the European Journal of Epidemiology paper listed above), I believe it demonstrates my ability to write methodological papers in a language that is accessible to non-methodologists; the paper has repeatedly been discussed on social media by applied epidemiologists who wish to understand collapsibility.

Recommended citation: Huitfeldt A, Stensrud MJ, Suzuki E. "On the collapsiblity of measures of effect in the counterfactual causal framework". Emerging Themes in Epidemiology 16(1), 2019 http://ahuitfeldt.github.io/files/paper5.pdf

The choice of effect measure for binary outcomes

Published in Epidemiologic Methods, 2018

This publication is the methodological foundation of my proposed theoretical framework for reasoning about generalizability of randomized trials. We introduce a new class of effect measures, the counterfactual outcome state transition (COST) parameters, and show how they can be used to derive results with important implications for meta-analysis and effect heterogeneity.

Recommended citation: Huitfeldt A, Goldstein A, Swanson SA. "The choice of effect measure for binary outcomes: Introducing counterfactual outcome state transition parameters". Epidemiologic Methods 2018, 2161-962X http://ahuitfeldt.github.io/files/paper4.pdf

Is caviar a risk factor for being a millionaire?

Published in BMJ, 2016

I argue that the term “risk factor” is ambiguous, and that this semantic ambiguity has resulted in methodological confusion. The paper was published in the Christmas Edition of the BMJ, received coverage in the press, and was extensively discussed on social media (Altmetrics score: 220).

Recommended citation: Huitfeldt, A. "Is caviar a risk factor for being a millionaire?". BMJ 2016;355:i6536 http://ahuitfeldt.github.io/files/paper3.pdf

Comparative effectiveness research using observational data: Active comparators to emulate target trials with inactive comparators

Published in eGEMs, 2016

This paper contributes to the theory of active comparators in clinical research. We discuss attempts to minimize bias in observational studies by using a comparator group consisting of individuals who initiate a drug unrelated to the outcome of interest, and clarify the conditions under which this approach leads to valid inferences.

Recommended citation: Huitfeldt A, Hernan MA, Kalager M, Robins JM. "Comparative effectiveness research using observational data: Active comparators to emulate target trials with inactive comparators". eGEMs: Vol. 4: Iss. 1, Article 20. http://ahuitfeldt.github.io/files/paper2.pdf

Methods to estimate the comparative effectiveness of clinical strategies that administer the same intervention at different times

Published in Current Epidemiology Reports, 2015

In clinical guidelines, it is often necessary to recommend how often a procedure should be repeated, and how the interval between procedures should be adapted to a patient’s risk profile based on earlier findings. We take steps towards formalizing an approach for answering such questions.

Recommended citation: Huitfeldt A, Kalager M, Robins JM, Hoff G, Hernan MA. "Methods to estimate the comparative effectiveness of clinical strategies that administer the same intervention at different times".Curr Epidemiol Reports 2015;2(3):149-61 http://ahuitfeldt.github.io/files/paper1.pdf

Anders Huitfeldt