Evidence map›Paper›PMID 37118802›Full record

ArticleTrials2023

Using re-randomisation designs to increase the efficiency and applicability of retention studies within trials: a case study.

Beatriz Goulao, Anne Duncan, Karen Innes, Craig R Ramsay, Brennan C Kahan

Abstract read
In one paragraph

Article in Trials, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
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

1 citing paper in PubMed.

  1. Trial
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

5 authors.

Beatriz GoulaoHealth Services Research Unit, University of Aberdeen, Aberdeen, Scotland. beatriz.goulao@abdn.ac.uk.ORCID http://orcid.org/0000-0003-1490-7183
Anne DuncanHealth Services Research Unit, University of Aberdeen, Aberdeen, Scotland.
Karen InnesHealth Services Research Unit, University of Aberdeen, Aberdeen, Scotland.
Craig R RamsayHealth Services Research Unit, University of Aberdeen, Aberdeen, Scotland.
Brennan C KahanMRC Clinical Trials Unit at UCL, London, UK.

Funding

Chief Scientist Office HSRU1Medical Research Council MC_UU_00004/07Medical Research Council MC_UU_00004/09
6 · The paper itself

Abstract

backgroundPoor retention in randomised trials can lead to serious consequences to their validity. Studies within trials (SWATs) are used to identify the most effective interventions to increase retention. Many interventions could be applied at any follow-up time point, but SWATs commonly assess interventions at a single time point, which can reduce efficiency.

methodsThe re-randomisation design allows participants to be re-enrolled and re-randomised whenever a new retention opportunity occurs (i.e. a new follow-up time point where the intervention could be applied). The main advantages are as follows: (a) it allows the estimation of an average effect across time points, thus increasing generalisability; (b) it can be more efficient than a parallel arm trial due to increased sample size; and (c) it allows subgroup analyses to estimate effectiveness at different time points. We present a case study where the re-randomisation design is used in a SWAT.

resultsIn our case study, the host trial is a dental trial with two available follow-up points. The Sticker SWAT tests whether adding the trial logo's sticker to the questionnaire's envelope will result in a higher response rate compared with not adding the sticker. The primary outcome is the response rate to postal questionnaires. The re-randomisation design could double the available sample size compared to a parallel arm trial, resulting in the ability to detect an effect size around 28% smaller.

conclusionThe re-randomisation design can increase the efficiency and generalisability of SWATs for trials with multiple follow-up time points.

Indexed as

Research DesignHumansSample SizeSurveys and QuestionnairesRe-randomisationRetentionSWAT (study within a trial)Trial methodologyTrials

Identifiers

PMID37118802
PMCPMC10148456

What OpenQuestion holds

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LicenceCC BY
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Registered trials

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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.