Evidence map›Paper›PMID 28153051›Full record

Trial reportTrials2017

Investigating the effect of independent, blinded digital image assessment on the STOP GAP trial.

Emily Patsko, Peter J Godolphin, Kim S Thomas, Trish Hepburn, Eleanor J Mitchell, Fiona E Craig, Philip M Bath, Alan A Montgomery

Open access · goldAbstract readComparative StudyMulticenter StudyRandomized Controlled Trial
In one paragraph

Trial report in Trials, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
2.6field-weighted citation impact, top 7% 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

2 citing papers in PubMed, 8 citations in OpenAlex.

  1. Trial
  2. 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

8 authors at 2 institutions in 1 country.

Emily PatskoNottingham Clinical Trials Unit, University of Nottingham, Nottingham, UK.
Peter J GodolphinNottingham Clinical Trials Unit, University of Nottingham, Nottingham, UK. peter.godolphin@nottingham.ac.uk.
Kim S ThomasCentre of Evidence Based Dermatology, University of Nottingham, Nottingham, UK.
Trish HepburnNottingham Clinical Trials Unit, University of Nottingham, Nottingham, UK.
Eleanor J MitchellNottingham Clinical Trials Unit, University of Nottingham, Nottingham, UK.
Fiona E CraigDepartment of Dermatology, Aberdeen Royal Infirmary, Aberdeen, UK.
Philip M BathStroke Trials Unit, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK.
Alan A MontgomeryNottingham Clinical Trials Unit, University of Nottingham, Nottingham, UK.
University of Nottingham · GBAberdeen Royal Infirmary · GB

Funding

Department of Health RP-PG-0407-10177
6 · The paper itself

Abstract

backgroundBlinding is the process of keeping treatment assignment hidden and is used to minimise the possibility of bias. Trials at high risk of bias have been shown to report larger treatment effects than low-risk studies. In dermatology, one popular method of blinding is to have independent outcome assessors who are unaware of treatment allocation assessing the endpoint using digital photographs. However, this can be complex, expensive and time-consuming. The objective of this study was to compare the effect of blinded and unblinded outcome assessment on the results of the STOP GAP trial.

methodsThe STOP GAP trial compared prednisolone to ciclosporin in treating pyoderma gangrenosum. Participants' lesions were measured at baseline and at 6 weeks to calculate the primary outcome, speed of healing. Independent blinded assessors obtained measurements from digital photographs using specialist software. In addition, unblinded treating clinicians estimated lesion area by measuring length and width. The primary outcome was determined using blinded measurements where available, otherwise unblinded measurements were used (method referred to as trial measurements). In this study, agreement between the trial and unblinded measurements was determined using the intraclass correlation coefficient (ICC). The STOP GAP trial's primary analysis was repeated using unblinded measurements only. We introduced differential and nondifferential error in unblinded measurements and investigated the effect on the STOP GAP trial's primary analysis.

resultsEighty-six (80%) of the 108 patients were assessed using digital images. Agreement between trial and unblinded measurements was excellent (ICC = 0.92 at baseline; 0.83 at 6 weeks). There was no evidence that the results of the trial primary analysis differed according to how the primary outcome was assessed (p value for homogeneity = 1.00).

conclusionsBlinded digital image assessment in the STOP GAP trial did not meaningfully alter trial conclusions compared with unblinded assessment. However, as the process brought added accuracy and credibility to the trial it was considered worthwhile. These findings question the usefulness of digital image assessment in a trial with an objective outcome and where bias is not expected to be excessive. Further research should investigate if there are alternative, less complex ways of incorporating blinding in clinical trials.

trial registrationCurrent Controlled Trials, www.isrctn.com ISRCTN35898459. Registered on 26 May 2009.

Indexed as

DermatologistsImage Interpretation, Computer-AssistedAdultAgedBiasCyclosporineFemaleHumansImmunosuppressive AgentsJudgmentMaleMiddle AgedObserver VariationPhotographyPredictive Value of TestsPrednisoloneCyclosporineImmunosuppressive AgentsPrednisoloneAdjudicationBlindingClinical trialsDigital imagesDigital photographsOutcome assessmentPyoderma gangrenosumRandomised controlled trial

Identifiers

PMID28153051
PMCPMC5288857
OpenAlexW2573718477

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.