Evidence map›Paper›PMID 42498954›Full record

ArticleDiagnostic and prognostic research2026

Treatment effect estimation by comparing observed and predicted outcomes: conditions for valid inference and practical illustration.

Lotta M Meijerink, Artuur M Leeuwenberg, Jungyeon Choi, Bas B L Penning de Vries, Johannes A Langendijk, Judith G M van Loon, Remi A Nout, Karel G M Moons, Ewoud Schuit

Abstract read
In one paragraph

Article in Diagnostic and prognostic research, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

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3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

Lotta M MeijerinkJulius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Universiteitsweg 100, 3508 GA, Utrecht, The Netherlands. l.m.meijerink-20@umcutrecht.nl.ORCID https://orcid.org/0000-0002-1511-6781
Artuur M LeeuwenbergJulius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Universiteitsweg 100, 3508 GA, Utrecht, The Netherlands.
Jungyeon ChoiJulius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Universiteitsweg 100, 3508 GA, Utrecht, The Netherlands.
Bas B L Penning de VriesJulius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Universiteitsweg 100, 3508 GA, Utrecht, The Netherlands.
Johannes A LangendijkDepartment of Radiation Oncology, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands.
Judith G M van LoonMAASTRO Clinic, Doctor Tanslaan 12, 6229 ET, Maastricht, The Netherlands.
Remi A NoutDepartment of Radiotherapy, Erasmus MC Cancer Institute, Dr Molewaterplein 40, 3015 GD, Rotterdam, The Netherlands.
Karel G M MoonsJulius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Universiteitsweg 100, 3508 GA, Utrecht, The Netherlands.
Ewoud SchuitJulius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Universiteitsweg 100, 3508 GA, Utrecht, The Netherlands.

Funding

ZonMw 10580012210025
6 · The paper itself

Abstract

backgroundOne non-randomized approach to estimate the average effect of a newly introduced treatment is to compare observed outcomes under the new treatment with predicted outcomes under the standard treatment. These counterfactual predictions are made using a model developed before the new treatment was introduced, using patient characteristics and individualized treatment information. Although the approach has been intuitively applied (e.g., as model-based clinical evaluation in radiotherapy) and can be recognized as a specific case of standardization, a method of virtual controls or a g-method, the theory and conditions required for unbiased treatment effect estimation have not been formally described. The objective of this paper is to formalize the approach and clarify these conditions.

methodsWe formalize the approach within the potential outcomes framework for causal inference. We explain the methodology, its necessary conditions, and approaches for assessing their validity. These conditions are furthermore illustrated through a case study from radiotherapy, estimating the benefit of proton therapy compared to photon therapy on dysphagia in patients with head and neck cancer.

resultsWe describe a set of five sufficient conditions, including examples of violations: transportability, ignorability of treatment assignment, consistency, positivity, and correct model specification. While these conditions are largely untestable, we describe how empirical evidence, such as comparing predicted and observed outcomes in related samples, can increase confidence in their plausibility.

conclusionWhen the prediction model predicts well in relevant (sub)populations, the approach can yield unbiased treatment effect estimates. However, there are many possible sources of bias. Therefore, we recommend systematic consideration of all required conditions, informed by domain expertise, and the use of empirical evidence whenever possible to support their plausibility.

Indexed as

ATTAverage treatment effect among the treatedCounterfactual predictionModel-based clinical evaluationTransportabilityVirtual controls

Identifiers

PMID42498954
PMCPMC13397745

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.