Evidence map›Paper›PMID 29843774›Full record

SynthesisTrials2018

Post-trial follow-up methodology in large randomised controlled trials: a systematic review.

Rebecca Llewellyn-Bennett, Danielle Edwards, Nia Roberts, Atticus H Hainsworth, Richard Bulbulia, Louise Bowman

Abstract readSystematic Review
PubMed Full text at PMC Publisher
In one paragraph

Synthesis in Trials, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 25 papers, 2 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
25citing papers in PubMed, 2 pooled it
–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

25 citing papers in PubMed, 2 syntheses or guidelines pooled it.

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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

6 authors.

Rebecca Llewellyn-BennettMRC Population Health Research Unit, Clinical Trial Service Unit (CTSU), Nuffield Department of Population Health, University of Oxford, Richard Doll Building, Roosevelt Drive, Oxford, OX3 7LF, UK. rebecca.llewellyn-bennett@ndph.ox.ac.uk.ORCID http://orcid.org/0000-0002-9708-9923
Danielle EdwardsMRC Population Health Research Unit, Clinical Trial Service Unit (CTSU), Nuffield Department of Population Health, University of Oxford, Richard Doll Building, Roosevelt Drive, Oxford, OX3 7LF, UK.
Nia RobertsBodleian Health Care Libraries, University of Oxford, Roosevelt Drive, Oxford, OX3 7LF, UK.
Atticus H HainsworthMolecular and Clinical Sciences Research Institute, St George's University of London, Cranmer Terrace, London, SW17 0RE, UK.
Richard BulbuliaMedical Research Council Population Health Research Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK.
Louise BowmanMedical Research Council Population Health Research Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK.

Funding

Medical Research Council MC_U137686861Medical Research Council MR/L023784/2National Centre for the Replacement, Refinement and Reduction of Animals in Research G0800701/1Royal College of Surgeons of England Research Fellowship
6 · The paper itself

Abstract

backgroundRandomised controlled clinical trials typically have a relatively brief in-trial follow-up period which can underestimate safety signals and fail to detect long-term hazards, which may take years to appear. Extended follow-up after the scheduled closure of the trial allows detection of both persistent or enhanced beneficial effects following cessation of study treatment (i.e. a legacy effect) and the emergence of possible adverse effects (e.g. development of cancer).

methodsA systematic review was conducted following PRISMA guidelines to qualitatively compare post-trial follow-up methods used in large randomised controlled trials. Five bibliographic databases, including Medline and the Cochrane Library, and one trial registry were searched. All large randomised controlled trials (more than 1000 adult participants) published from March 2006 to April 2017 were evaluated. Two reviewers screened and extracted data attaining > 95% concordance of papers checked. Assessment of bias in the trials was evaluated using the Cochrane Risk of Bias tool.

resultsFifty-seven thousand three hundred and fifty-two papers were identified and 65 trials which had post-trial follow-up (PTFU) were included in the analysis. The majority of trials used more than one type of follow-up. There was no evidence of an association between the retention rates of participants in the PTFU period and the type of follow-up used. Costs of PTFU varied widely with data linkage being the most economical. It was not possible to assess associations between risk of bias during the in-trial period and proportions lost to follow-up during the PTFU period. DISCUSSION: Data captured during the post-trial follow-up period can add scientific value to a trial. However, there are logistical and financial barriers to overcome. Where available, data linkage via electronic registries and records is a cost-effective method which can provide data on a range of endpoints. SYSTEMATIC REVIEW REGISTRATION: Not applicable for PROSPERO registration.

Indexed as

Research DesignEndpoint DeterminationFollow-Up StudiesHumansPatient DropoutsRandomized Controlled Trials as TopicTime FactorsTreatment OutcomeCostEffectiveFollow-upLong-termMethodologyPost-trialRandomised controlled trialRetention

Identifiers

PMID29843774
PMCPMC5975470

What OpenQuestion holds

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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.