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Brennan Kahan

@brennankahan.bsky.social
770 followers 305 following 40 posts

Principal Research Fellow in Medical Statistics at MRC Clinical Trials Unit at UCL. Clinical trials, estimands, estimation. scholar.google.co.uk/citations?user…

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Reposted by Brennan Kahan
Jack Wilkinson @jdwilko.bsky.social · 24/09/2026
The integrity of evidence synthesis is threatened by problematic randomised controlled trials. These may be fraudulent, or subject to critical errors. INSPECT-SR is a tool to assess trustworthiness of RCTs - out today: www.bmj.com/content/394/...
bmj.com
INSPECT-SR tool for assessing trustworthiness of randomised controlled trials
The integrity of evidence synthesis is threatened by problematic randomised controlled trials, where there are serious concerns about the trustworthiness of the data or findings. Such concerns could b...
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The Cochrane Collaboration @cochrane.org · 24/09/2026
INSPECT-SR – a tool for assessing the trustworthiness of randomized controlled trials – has been published today in @bmj.com, giving researchers a structured way to identify problematic studies before they're included in systematic reviews. 🔗 www.cochrane.org/about-us/new... #ResearchIntegrity
“Systematic reviews are only as credible as the studies they include.” — phrased as a Cochrane senior research integrity editor; a magnifying glass rests on stacked papers in the background to emphasize careful scrutiny of research.
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Brennan Kahan @brennankahan.bsky.social · 21/09/2026
Reminder: job opportunity for 3 Statistical Methodologists (research fellow/senior research fellow level) to work at UCL. Closing date: Friday, September 25th.
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Michael Marks @drmichaelmarks.bsky.social · 15/09/2026
Applications closing this week. Looking for a mathematical modeller to come and work on STI modelling @lshtm.bsky.social - 3yr funded post-doc. @sbfnk.bsky.social @rozeggo.bsky.social @nicolamlow.bsky.social @drlouisedyson.bsky.social @cmmid-lshtm.bsky.social @thomrawson.bsky.social @banks.ac
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Brennan Kahan @brennankahan.bsky.social · 15/09/2026
***JOB ALERT*** We are seeking to appoint 3 Statistical Methodologists to work on methods related to the statistical analysis of clinical trials, or innovative design methodology. The posts will be based within the UCL Institute of Clinical Trials and Methodology. www.ucl.ac.uk/work-at-ucl/...
ucl.ac.uk
UCL – University College London
UCL is consistently ranked as one of the top ten universities in the world (QS World University Rankings 2010-2022) and is No.2 in the UK for research power (Research Excellence Framework 2021).
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Richard Riley (R²) @richarddriley.bsky.social · 11/09/2026
We've got two online IPD meta-analysis training courses this Autumn, with places still available - one is a general introduction about doing IPDMA projects (the whole process, not just the stats bit) & the other is about the statistical modelling aspects - more here: www.ipdma.co.uk/training-cou...
ipdma.co.uk
Training courses | IPD Meta-Analysis
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Reposted by Brennan Kahan
Journal of Clinical Epidemiology @jclinepi.bsky.social · 24/08/2026
Choice of estimands and estimators affected the interpretation of results for some outcomes in a cluster-randomised trial (RESTORE) due to informative cluster size - Journal of Clinical Epidemiology www.jclinepi.com/article/S089...
jclinepi.com
Choice of estimands and estimators affected the interpretation of results for some outcomes in a cluster-randomised trial (RESTORE) due to informative cluster size
In cluster-randomised trials (CRTs), different estimands can be targeted, such as the individual- or cluster-average effect. These two estimands can differ in magnitude when outcomes or treatment effe...
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Reposted by Brennan Kahan
Richard Riley (R²) @richarddriley.bsky.social · 31/07/2026
*NEW ARTICLE* - delighted to announce that the MEMTAB 2025 abstracts are now published in Diagnostic and Prognostic Research! link.springer.com/article/10.1...
link.springer.com
Methods for Evaluating Models, Tests And Biomarkers (MEMTAB): Abstracts from the 7th International Conference, MEMTAB 2025 - Diagnostic and Prognostic Research
Diagnostic and Prognostic Research -
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Marion Campbell @marionkcampbell.bsky.social · 16/07/2026
We are hiring!! Our trials unit, CHaRT, is looking to appoint a Deputy Director (Methodology). The role will provide methodological leadership across CHaRT’s portfolio. A really exciting opportunity for anyone interested in a leadership role in clinical trials!! See: www.abdn.ac.uk/jobs/vacanci...
abdn.ac.uk
Deputy Director (Methodology), Medicine, Medical Sciences & Nutrition (ACE014A) | The University of Aberdeen
University of Aberdeen Research Jobs
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Reposted by Brennan Kahan
Jack Wilkinson @jdwilko.bsky.social · 24/06/2026
Next INSPECT-SR training workshop: July 23rd www.trybooking.com/uk/events/la...
trybooking.com
Introduction to INSPECT-SR Training Workshop July
An introductory 2-hour online workshop will introduce participants to the INSPECT-SR tool for assessing trustworthiness of randomised controlled...
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Reposted by Brennan Kahan
Richard Riley (R²) @richarddriley.bsky.social · 11/06/2026
NEW VIDEO: "Systematic Reviews of Prognosis Research & Prediction Models" - a broad 20 minute introduction, concluding with some exciting news for the field! youtu.be/CgYvaOG2Ta8
youtu.be
Systematic Reviews of Prognosis Research & Prediction Models
YouTube video by Richard_D_Riley
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Richard Riley (R²) @richarddriley.bsky.social · 10/06/2026
COURSE: 'Statistical Methods for Risk Prediction & Prognostic Models' - last chance to book for this online course (6th to 9th July 2026) - more details at www.prognosisresearch.com/training-cou...
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Gary Collins @gscollins.bsky.social · 28/05/2026
NEW #openaccess PAPER in Lancet Digital Health “Critical appraisal of fairness metrics for artificial intelligence-based clinical prediction models” www.thelancet.com/journals/lan... #predictiveAI #digitaltech #AI #machinelearning #datascience #fairness #healthequity
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Marion Campbell @marionkcampbell.bsky.social · 25/05/2026
There is also a short explainer published in #JAMA 8/8 jamanetwork.com/journals/jam...
jamanetwork.com
The CRT-Estimands Framework for Cluster Randomized Trials
This Viewpoint discusses some specific challenges in defining estimands for cluster randomized trials and illustrates how the CRT-Estimands Framework can be applied to improve the interpretation of tr...
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Marion Campbell @marionkcampbell.bsky.social · 25/05/2026
The full text of the extended estimand framework for cluster trials was published in the BMJ led by @brennankahan.bsky.social 7/8 www.bmj.com/content/393/...
bmj.com
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Marion Campbell @marionkcampbell.bsky.social · 25/05/2026
These include specifying the population of both clusters and individuals; outlining how intercurrent events will be handled at both levels, how clusters are weighted and whether summaries are marginal or cluster specific 6/8
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Marion Campbell @marionkcampbell.bsky.social · 25/05/2026
The cluster trials (cRCT) estimand framework extension outlines what exactly needs to be made explicit in a cluster trial estimand - there are five key things be considered 5/8
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Marion Campbell @marionkcampbell.bsky.social · 25/05/2026
In cluster trials, how we deal with the clusters can affect the estimate of the treatment effect, so we also need to be really clear about what exactly we are estimating, in whom and how, otherwise the reported treatment effect may be misinterpreted 4/8
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Marion Campbell @marionkcampbell.bsky.social · 25/05/2026
“Intercurrent events” are post-randomisation events (eg discontinuation/switching of treatment etc) and the estimand describes how these events will be handled in the analysis. In cluster trials these can happen at both the cluster and the individual level 3/8
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Marion Campbell @marionkcampbell.bsky.social · 25/05/2026
An #estimand is effectively a more precise specification of the research question(s) and how the treatment effect is to be estimated (hence estimand). It also precisely describes how so called “intercurrent events” will be handled in the analysis. 2/8
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Marion Campbell @marionkcampbell.bsky.social · 25/05/2026
At the Society of Clinical Trials (#SCT2026) conference last week, one of the topics being discussed was estimands & intercurrent events in cluster trials. Perfect timing for the publication of the new cRCT estimand framework 1/8 #MethodologyMonday #129
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Richard Riley (R²) @richarddriley.bsky.social · 22/05/2026
🎬 I've just uploaded a new video explaining the premise of our new general sample size framework for prediction model development, and how it embeds and extends previous work youtu.be/eglPq1aTl7k
youtu.be
A general sample size framework for developing or updating a predictive algorithm (prediction model)
YouTube video by Richard_D_Riley
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Reposted by Brennan Kahan
Gary Collins @gscollins.bsky.social · 21/05/2026
*** NEW PAPER *** The CRT-Estimands Framework - a consensus based extension of the ICH E9(R1) addendum for cluster randomised trials - now been published in the @bmj.com. -> www.bmj.com/content/393/... + commentary in @jama.com -> jamanetwork.com/journals/jam... @unibirmingham.bsky.social
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JAMA @jama.com · 21/05/2026
💬 Viewpoint: The #CRT-Estimands Framework defines five key attributes for cluster randomized trials, clarifying treatment effect and supporting accurate result interpretation for clinical stakeholders. ja.ma/4wG0Vcx
An excerpt from JAMA, titled 'The CRT-Estimands Framework for Cluster Randomized Trials' by Brennan C. Kahan, PhD, et al., includes a table outlining attributes and explanations related to study design and analysis.
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Darren Dahly @statsepi.bsky.social · 20/05/2026
Happy #ClinicalTrials Day Trial design and conduct is no place for novices with best intentions. Patient participants make sacrifices. Medical progress holds its breath. Large sums of public and private money is invested. So get it right, from the start. statsepi.substack.com/p/dealing-wi...
statsepi.substack.com
Dealing with
There are no negative trials - just ones we learn from and ones we don't
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Jonathan Bartlett @jonathan-bartlett.bsky.social · 13/05/2026
Perspectives on statistics in medicine: Annual joint LSHTM/RSS lecture on 16th June, by Prof. Marion Campbell. Further details here: www.lshtm.ac.uk/newsevents/e...
lshtm.ac.uk
Perspectives on statistics in medicine: Annual joint LSHTM/RSS lecture | LSHTM
Future directions in the evaluation of innovative technologies in healthcare: Technology in healthcare is rapidly advancing. For example, a recent healthcare report suggests that 9 out of 10
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Munya Dimairo @mdimairo.bsky.social · 08/05/2026
We are seeking key stakeholders in clinical trials research and related decision-making processes to contribute to guidance development on statistical analysis plans for adaptive and platform trials and on the disclosure of interim information in these trials. See details below 👇🏾👇🏾
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Richard Riley (R²) @richarddriley.bsky.social · 28/04/2026
My wife’s short film ‘Opening Up’ is now free to watch! A romantic comedy drama starring Tamsin Outhwaite and Gary Beadle, it’s won lots of festival awards and was even selected for the HollyShorts Film Festival in LA. Enjoy 🙏 www.youtube.com/watch?v=OEdy...
youtube.com
Opening Up | Drama Short Film | British Romance
YouTube video by CenterFrame | Filmmakers Community
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Tim Morris @timpmorris.bsky.social · 27/03/2026
There’s a very nice commentary on the tension between relevance and reliability. ‘What Makes an Estimand Useful? Guidance on the Choice of Intercurrent Event Strategies’ By @brennankahan.bsky.social Fan Li, Michael Harhay & @suziecro.bsky.social 4/ doi.org/10.1002/sim....
doi.org
What Makes an Estimand Useful? Guidance on the Choice of Intercurrent Event Strategies
While the use of estimands in randomized trials is increasing, there is little guidance on which intercurrent event strategies should be used. The article by Fleming et al. seeks to address this gap....
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Tim Morris @timpmorris.bsky.social · 27/03/2026
New commentary in Statistics in Medicine: ‘A Causal Perspective on “Appropriate Implementation of ICH E9(R1) Addendum Strategies” (Comment on Fleming et al.)’ By me, Alex Ocampo, Jesper Madsen, Hege Michiels, Sanne Roels. 1/ doi.org/10.1002/sim....
doi.org
A Causal Perspective on “Appropriate Implementation of ICH E9(R1) Addendum Strategies” (Comment on Fleming et al.)
This commentary offers perspectives on delivering “rigorous causal inference on meaningful estimands” that differ from the opinions recently shared by Fleming et al. We (1) depict a more robust pathw...
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Donald Szlosek @dszlosek.bsky.social · 24/03/2026
For anyone who is doing statistical simulation work, I honestly cannot recommend @timpmorris.bsky.social's elegant 2019 manuscript on ADEMP framework enough. Outlining a structured approach to planning sim studies, w/in-depth examples+how to display Monte Carlo SEs. #statssky#statistics #academicsky
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Laure Wynants @laurewynants.bsky.social · 18/03/2026
✨ New open-access book✨ I’ve seen how powerful prediction models can be, but also how often they fall short. We wrote a book, covering not just development, but also when models are needed, and how to ensure real-world impact. www.maastrichtuniversitypress.nl/cpm
maastrichtuniversitypress.nl
%%title%% %%sep%% Maastricht University Press
Open Access book by Luc Smits, Sander van Kuijk, and Laure Wynants: This open-access textbook offers a practical and comprehensive guide to developing, validating, and implementing clinical prediction...
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Triad sou. @triadsou.bsky.social · 18/03/2026
A Causal Perspective on “Appropriate Implementation of ICH E9(R1) Addendum Strategies” (Comment on Fleming et al.) Tim P. Morris, Alex Ocampo, Jesper Madsen, Hege Michiels, Sanne Roels. Statistics in Medicine. onlinelibrary.wiley.com/doi/10.1002/...
onlinelibrary.wiley.com
A Causal Perspective on “Appropriate Implementation of ICH E9(R1) Addendum Strategies” (Comment on Fleming et al.)
This commentary offers perspectives on delivering “rigorous causal inference on meaningful estimands” that differ from the opinions recently shared by Fleming et al. We (1) depict a more robust pathw...
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Reposted by Brennan Kahan
Triad sou. @triadsou.bsky.social · 18/03/2026
What Makes an Estimand Useful? Guidance on the Choice of Intercurrent Event Strategies. Brennan C. Kahan, Fan Li, Michael O. Harhay, Suzie Cro. Statistics in Medicine. onlinelibrary.wiley.com/doi/10.1002/...
onlinelibrary.wiley.com
What Makes an Estimand Useful? Guidance on the Choice of Intercurrent Event Strategies
While the use of estimands in randomized trials is increasing, there is little guidance on which intercurrent event strategies should be used. The article by Fleming et al. seeks to address this gap....
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Eslam Maher @eslammaher.bsky.social · 18/03/2026
COMMENTARY: What Makes an Estimand Useful? Guidance on the Choice of Intercurrent Event Strategies @brennankahan.bsky.social @suziecro.bsky.social onlinelibrary.wiley.com/doi/full/10....
onlinelibrary.wiley.com
What Makes an Estimand Useful? Guidance on the Choice of Intercurrent Event Strategies
While the use of estimands in randomized trials is increasing, there is little guidance on which intercurrent event strategies should be used. The article by Fleming et al. seeks to address this gap....
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Reposted by Brennan Kahan
Journal of Clinical Epidemiology @jclinepi.bsky.social · 22/02/2026
The epistemological trap from the real-world evidence concept. - Journal of Clinical Epidemiology www.jclinepi.com/article/S089...
jclinepi.com
The epistemological trap from the real-world evidence concept.
‘Real-world’ evidence (RWE) and related terms are gaining popularity in scientific literature, usually in reference to evidence collected outside of traditional randomized controlled trials (RCT). How...
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GESIS Training @gesistraining.bsky.social · 02/03/2026
*Using Simulation Studies to Evaluate Statistical Methods* by @matteoq21.bsky.social & Tra My Pham (@mrcctu.bsky.social). 🗓️ 19 – 20 & 26 – 27 November 2026 🏢 Online 🌐 t1p.de/simulation_s...
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Pausal Zivference @pausalz.bsky.social · 11/02/2026
As a known HR hater, it brings me no joy to post this but I do think some papers are a bit sloppy with their criticisms of the HR (as highlighted by this nice paper) Some say the overall HR is not causal. But I don't think this is the case for reasons provided here
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AusTriM CRE @austrim-cre.bsky.social · 04/02/2026
"An online sample size calculator for designing partially clustered trials" (@klange-au.bsky.social et al) has now been published in Clinical Trials! doi.org/10.1177/1740... This free and user-friendly online calculator makes it easier to ensure a trial is appropriately powered ✅
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Tim Morris @timpmorris.bsky.social · 09/01/2026
New post on a topic you might have struggled with if you do simulation studies. For a given data-generating mechanism, you might wonder “What is the true value of my estimand?” This post describes four ways to learn it. tpmorris.substack.com/p/learning-t...
Banner for blog post, showing the title and part of the image in the post (with its own alt text in the post).
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OCTRU Trials Hub @octructu.bsky.social · 05/01/2026
New Year, New Job? 📆 If you'd like to contribute to the design, conduct & analysis of research projects (and more!), we are looking for a Medical Statistician to join our team! Apply by 2nd Feb, 12 noon. Find out more, and see all of OCTRU's vacancies here: www.ndorms.ox.ac.uk/octru/about-...
The words 'JOB VACANCY' on the left hand side, and the OCTRU logo on the right hand side, on a white background showing graphs
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Tim Feeney @tfeend.bsky.social · 19/12/2025
As an editor I often see authors fall into a trap of stressing some fancy statistical technique for estimating causal effects. Often neglected are the necessary assumptions to map the data to the estimand. @pausalz.bsky.social and I wrote about it here www.bmj.com/content/391/... #EpiSky
bmj.com
Causal inference is hard, and advanced statistical analysis is not enough
Health researchers need to fully understand the underlying assumptions to uncover cause and effect. Timothy Feeney and Paul Zivich explain Physicians ask, answer, and interpret myriad causal question...
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Brennan Kahan @brennankahan.bsky.social · 05/12/2025
New paper in @jclinepi.bsky.social: **Estimands: what they are and why we should use them** We provide simple explanations of: -estimands and intercurrent events -how these relate to familliar concepts like ITT -how to write estimands for protocols -and more www.jclinepi.com/article/S089...
jclinepi.com
Estimands: what they are and why we should use them
In clinical trials, postrandomization events, such as treatment discontinuation or the use of rescue medication, can complicate the interpretation of results. An estimand is a precise description of t...
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Darren Dahly @statsepi.bsky.social · 05/12/2025
Just a reminder about the new all-island Irish Reproducibility Network. There are already lots of great people involved. You can sign up and find local site leads with the link, and if you are based in Cork feel free to reach out to me directly. irishrn.org
irishrn.org
Home - Irish Reproducibility Network
My WordPress Blog
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Gary Collins @gscollins.bsky.social · 07/11/2025
NEW PAPER: "Reporting guidelines for studies involving generative artificial intelligence applications: what do I use, and when?" --> www.nature.com/articles/s41... #HealthTech #ClinicalAI #MachineLearning #MedAI #AIinMedicine #TransparentAI #HealthInnovation #GenAI
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Marion Campbell @marionkcampbell.bsky.social · 03/11/2025
The term #estimand is now part of the technical language of trials - but it remains a concept that many find hard to understand. Recent work has aimed to make the term more accessible to researchers, patients & public 1/8 #MethodologyMonday #127
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Gary Collins @gscollins.bsky.social · 30/10/2025
NEW paper "Clinical prediction models using machine learning in oncology: challenges and recommendations" --> tinyurl.com/2h2mcy5h #machinelearning #prediction #statssky #MLsky #methodsmatter
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StatsCI @statsci.bsky.social · 28/10/2025
📢 New publication in #Trials led by @suziecro.bsky.social with the HEALTHY STATS public involvement group: Supporting public involvement in defining estimands: a practical tool accessibly explaining the five key attributes of an estimand trialsjournal.biomedcentral.com/articles/10....
trialsjournal.biomedcentral.com
Supporting public involvement in defining estimands: a practical tool accessibly explaining the five key attributes of an estimand - Trials
Background An estimand is a precise description of the treatment effect a trial is aiming to find out. We previously identified that public partners (defined as patients and/or members of the public w...
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UCL Innovative Clinical Trials Unit @innovative-ctu.bsky.social · 27/10/2025
We're excited to share our latest work on estimands in clinical trials! 📄 Estimating treatment effects in trials with outcome data truncated by death: A case study on aligning estimators with estimands. 🔗 Read the full paper: journals.sagepub.com/doi/10.1177/...
journals.sagepub.com
Sage Journals: Discover world-class research
Subscription and open access journals from Sage, the world's leading independent academic publisher.
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