在有效疣治疗试验（EverT）中实施盲法结局评估——经验教训

Implementation of blinded outcome assessment in the Effective Verruca Treatments trial (EverT) - lessons learned.

作者信息

Cockayne Sarah, Hewitt Catherine, Hashmi Farina, Hicks Kate, Concannon Michael, McIntosh Caroline, Thomas Kim, Hall Jill, Watson Judith, Torgerson David, Watt Ian

机构信息

Department of Health Sciences, York Trials Unit, University of York, York, UK.

School of Health Sciences, University of Salford, Salford, UK.

出版信息

J Foot Ankle Res. 2016 Jul 12;9:21. doi: 10.1186/s13047-016-0155-4. eCollection 2016.

DOI:10.1186/s13047-016-0155-4

PMID:27408622

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC4941023/

Abstract

BACKGROUND

Trials using inadequate levels of blinding may report larger effect sizes than blinded studies. It has been suggested that blinded outcome assessment in open trials may in some cases be undertaken by assessments of photographs. The aim of this paper is to explore the effect of using different methods to assess the primary outcome in the EVerT (Effective Verruca Treatments) trial. It also aims to give an overview of the experiences of using digital photographs within the trial.

METHODS

We undertook a secondary analysis to explore the effect of using three different methods to assess the primary outcome in the EVerT trial: assessment of digital photographs by blinded healthcare professionals; blinded healthcare professional assessment at the recruiting site and patient self-report. The verruca clearance rates were calculated using the three different methods of assessment. A Cohen's kappa measure of inter-rater agreement was used to assess the agreement between the methods. We also investigated the experiences of healthcare professionals using digital photographs within the trial.

RESULTS

Digital photographs for 189 out of 240 (79 %) patients in the trial were received for outcome assessment. Of the 189 photographs, 30 (16 %) were uninterpretable. The overall verruca clearance rates were 21 % (43/202,) using the unblinded patient self-reported outcome, 6 % (9/159,) using blinded assessment of digital photographs and 14 % (30/210,) using blinded outcome assessment at the site.

CONCLUSIONS

Despite differences in the clearance rates found using different methods of outcome assessment, this did not change the original conclusion of the trial, that there is no evidence of a difference in effectiveness between cryotherapy and salicylic acid. Future trials using digital photographs should consider individual training needs at sites and have a backup method of assessment agreed a priori.

TRIAL REGISTRATION

ISRCTN Registry ISRCTN18994246.

摘要

背景

与采用盲法的研究相比，使用盲法水平不足的试验可能报告更大的效应量。有人提出，在开放试验中，盲法结局评估在某些情况下可通过对照片的评估来进行。本文旨在探讨在EVerT（有效跖疣治疗）试验中使用不同方法评估主要结局的效果。它还旨在概述在试验中使用数码照片的经验。

方法

我们进行了一项二次分析，以探讨在EVerT试验中使用三种不同方法评估主要结局的效果：由盲法医疗专业人员评估数码照片；在招募地点由盲法医疗专业人员评估以及患者自我报告。使用三种不同的评估方法计算跖疣清除率。采用Cohen's kappa评分者间一致性测量法来评估这些方法之间的一致性。我们还调查了医疗专业人员在试验中使用数码照片的经验。