Evidence map›Paper›PMID 33302878›Full record

ArticleBMC medical research methodology2020

Integrating expert opinions with clinical trial data to analyse low-powered subgroup analyses: a Bayesian analysis of the VeRDiCT trial.

Russell Thirard, Raimondo Ascione, Jane M Blazeby, Chris A Rogers

Open access · goldAbstract read
In one paragraph

Article in BMC medical research methodology, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.

0numbers the graph read from it
0cells of the map it votes in
4citing papers in PubMed
1.1field-weighted citation impact, top 19% of its field
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.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

4 citing papers in PubMed, 9 citations in OpenAlex.

  1. Article
  2. Article
  3. Article
  4. Informed Bayesian survival analysis.BMC medical research methodology · 2022
    Article
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

4 authors at 3 institutions in 1 country.

Russell ThirardBristol Trials Centre (BTC), University of Bristol, Zone A, level 7, Bristol Royal Infirmary, Bristol, BS2 8HW, UK. russell.thirard@bristol.ac.uk.ORCID 0000-0002-1441-1834
Raimondo AscioneBristol Heart Institute, Bristol Medical School, University of Bristol, Bristol, UK.
Jane M BlazebyNational Institute for Health Research Bristol Biomedical Research Centre, Bristol, UK.
Chris A RogersBristol Trials Centre (BTC), University of Bristol, Zone A, level 7, Bristol Royal Infirmary, Bristol, BS2 8HW, UK.
Bristol Royal Infirmary · GBUniversity Hospitals Bristol NHS Foundation Trust · GBUniversity of Bristol · GB

Funding

Medical Research Council MR/K025643/1Research Trainees Coordinating Centre NIHR-RM-FI-2017-08-017
6 · The paper itself

Abstract

backgroundTypically, subgroup analyses in clinical trials are conducted by comparing the intervention effect in each subgroup by means of an interaction test. However, trials are rarely, if ever, adequately powered for interaction tests, so clinically important interactions may go undetected. We discuss the application of Bayesian methods by using expert opinions alongside the trial data. We applied this methodology to the VeRDiCT trial investigating the effect of preoperative volume replacement therapy (VRT) versus no VRT (usual care) in diabetic patients undergoing cardiac surgery. Two subgroup effects were of clinical interest, a) preoperative renal failure and b) preoperative type of antidiabetic medication.

methodsClinical experts were identified within the VeRDiCT trial centre in the UK. A questionnaire was designed to elicit opinions on the impact of VRT on the primary outcome of time from surgery until medically fit for hospital discharge, in the different subgroups. Prior beliefs of the subgroup effect of VRT were elicited face-to-face using two unconditional and one conditional questions per subgroup analysis. The robustness of results to the 'community of priors' was assessed. The community of priors was built using the expert priors for the mean average treatment effect, the interaction effect or both in a Bayesian Cox proportional hazards model implemented in the STAN software in R.

resultsExpert opinions were obtained from 7 clinicians (6 cardiac surgeons and 1 cardiac anaesthetist). Participating experts believed VRT could reduce the length of recovery compared to usual care and the greatest benefit was expected in the subgroups with the more severe comorbidity. The Bayesian posterior estimates were more precise compared to the frequentist maximum likelihood estimate and were shifted toward the overall mean treatment effect.

conclusionsIn the VeRDiCT trial, the Bayesian analysis did not provide evidence of a difference in treatment effect across subgroups. However, this approach increased the precision of the estimated subgroup effects and produced more stable treatment effect point estimates than the frequentist approach. Trial methodologists are encouraged to prospectively consider Bayesian subgroup analyses when low-powered interaction tests are planned.

trial registrationISRCTN, ISRCTN02159606 . Registered 29th October 2008.

Indexed as

Bayes TheoremClinical Trials as TopicHumansLikelihood FunctionsProportional Hazards ModelsSurveys and QuestionnairesBayesian analysisCardiac surgeryElicitationSubgroup analysesSurvivalVolume replacement therapy

Identifiers

PMID33302878
PMCPMC7727208
OpenAlexW3112949972

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

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.