Investigating the effect of independent, blinded digital image assessment on the STOP GAP trial.
Background: Blinding 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 outc...
| Publicado en: | Trials Vol. 18; pp. 1 - 11 |
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| Autores principales: | , , , , , , , |
| Formato: | research randomized controlled trial Journal Article |
| Publicado: |
BioMed Central
2/2/2017
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=122975554&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 122975554 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 17456215 38OC jtl: Trials issn: 17456215 maglogo: N pubinfo: dt: 2/2/2017 vid: 18 pid: 24147 pub: BioMed Central artinfo: ui: 122975554 122975554 NLM28153051 122975554 10.1186/s13063-017-1779-9 NLM28153051 122975554 ppf: 1 ppct: 10 formats: tig: atl: Investigating the effect of independent, blinded digital image assessment on the STOP GAP trial. aug: au: Patsko, Emily Godolphin, Peter J. Thomas, Kim S. Hepburn, Trish Mitchell, Eleanor J. Craig, Fiona E. Bath, Philip M. Montgomery, Alan A. affil: Nottingham Clinical Trials Unit, University of Nottingham, Nottingham, UK sug: subj: Pyoderma Gangrenosum Drug Therapy Skin Drug Effects Prednisolone Therapeutic Use Immunosuppressive Agents Therapeutic Use Photography Methods Cyclosporine Therapeutic Use Image Interpretation, Computer Assisted Pyoderma Gangrenosum Pathology Aged Cyclosporine Adverse Effects Software Time Factors Wound Healing Drug Effects Male Female Prednisolone Adverse Effects Human Middle Age Reproducibility of Results Judgment Skin Pathology Adult Immunosuppressive Agents Adverse Effects Predictive Value of Tests Observer Bias Study Design Treatment Outcomes Comparative Studies Multicenter Studies Randomized Controlled Trials Evaluation Research Validation Studies Scales Ways of Coping Questionnaire Aged: 65+ years Middle Aged: 45-64 years Adult: 19-44 years Male Female ab: Background: Blinding 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.Methods: The 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.Results: Eighty-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).Conclusions: Blinded 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 Registration: Current Controlled Trials, www.isrctn.com ISRCTN35898459. Registered on 26 May 2009. pubtype: Academic Journal doctype: research randomized controlled trial Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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