Controlled trials: allocation concealment, random allocation, and blinding

BMJ ◽  
2015 ◽  
Vol 350 (may15 2) ◽  
pp. h2633-h2633 ◽  
Author(s):  
P. Sedgwick
Keyword(s):  
Allocation Concealment ◽  
Controlled Trials ◽  
Random Allocation

scholarly journals Randomized Controlled Trials on Complementary and Traditional Medicine in the Korean Literature

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Chang-Kyu Kim ◽  
Da-Hee Kim ◽  
Myeong Soo Lee ◽  
Jong-In Kim ◽  
L. Susan Wieland ◽  
...  
Keyword(s):  
Randomized Controlled Trials ◽  
Traditional Medicine ◽  
Systematic Reviews ◽  
Allocation Concealment ◽  
Risk Of Bias ◽  
Controlled Trials ◽  
Korean Literature ◽  
Language Bias ◽  
Randomized Controlled ◽  
Study Characteristics

Objective. This study aimed to identify all of the features of complementary and alternative (CAM) randomized controlled trials (RCTs) in the Korean literature and then introduce English-speaking researchers to the bibliometric and risk of bias characteristics of this literature.Methods. Eleven electronic databases and sixteen Korean journals were searched to August 2013 for RCTs of CAM therapies. Key study characteristics were extracted and risk of bias was assessed using the Cochrane Collaboration’s tool for assessing risk of bias.Results. Three hundred and sixty publications met our inclusion criteria. Complementary and traditional medicine RCTs in the Korean literature emerged in the mid-1990s and increased in the mid-2000s. The most common CAM interventions include acupuncture (59.4%) and herbal medicine (8.3%). The largest proportion of trials evaluated CAM for musculoskeletal conditions (20.7%). Adequate methods of randomization were reported in 41.7% of the RCTs, whereas only 8.3% reported adequate allocation concealment. A low proportion of trials reported participant blinding (34.2%) and outcome assessor blinding (22.5%).Conclusions. Korean CAM RCTs are typically omitted from systematic reviews resulting in the potential for language bias. This study will enable these trials of diverse quality to be identified and assessed for inclusion in future systematic reviews on CAM interventions.

Using scratch card technology for random allocation concealment in a clinical trial with a crossover design

2012 ◽  
Vol 10 (1) ◽  
pp. 125-130 ◽  
Author(s):  
Mags E Beksinska ◽  
Carol Joanis ◽  
Jenni A Smit ◽  
Jacqueline Pienaar ◽  
Gilda Piaggio
Keyword(s):  
Clinical Trial ◽  
Allocation Concealment ◽  
Crossover Design ◽  
Random Allocation

Assessment of Reporting Quality in Randomised Controlled Trials of Acupuncture for Post-Stroke Rehabilitation Using the Consort Statement and Stricta Guidelines

2017 ◽  
Vol 35 (2) ◽  
pp. 100-106 ◽  
Author(s):  
Jingchun Zeng ◽  
Guohua Lin ◽  
Lixia Li ◽  
Liming Lu ◽  
Chuyun Chen ◽  
...  
Keyword(s):  
Stroke Rehabilitation ◽  
Randomised Controlled Trials ◽  
Reporting Quality ◽  
Consort Statement ◽  
Allocation Concealment ◽  
Controlled Trials ◽  
Quality Of Reporting ◽  
Post Stroke ◽  
Randomised Controlled

Objectives To evaluate the completeness of reporting of randomised controlled trials (RCTs) of acupuncture for post-stroke rehabilitation in order to provide information to facilitate transparent and more complete reporting of acupuncture RCTs in this field. Methods Multiple databases were searched from their inception through September 2015. Quality of reporting for included papers was assessed against a subset of criteria adapted from the Consolidated Standards for Reporting Trials (CONSORT) 2010 statement and the Standards for Reporting Interventions in Controlled Trials of Acupuncture (STRICTA) guidelines. Each item was scored 1 if it was reported, or 0 if it was not clearly stated. Descriptive statistical analysis was performed. Cohen's κ-statistics were calculated to assess agreement between the two reviewers. Results A total of 87 RCTs were included in the full text. Based on CONSORT, good reporting was evident for items “Randomised’ in the title or abstract’, ‘Participants’, ‘Statistical methods’, ‘Recruitment’, ‘Baseline data’, and ‘Outcomes and estimation’, with positive rates >80%. However, the quality of reporting for the items ‘Trial design’, ‘Outcomes’, ‘Sample size’, ‘Allocation concealment’, ‘Implementation’, ‘Blinding’, ‘Flow chart’, ‘Intent-to-treat analysis’, and ‘Ancillary analyses’ was very poor with positive rates <10%. Based on STRICTA, the items ‘Number of needle insertions per subject per session’, ‘Responses sought’, and ‘Needle type’ had poor reporting with positive rates <50%. Substantial agreement was observed for most items and good agreement was observed for some items. Conclusions The reporting quality of RCTs in acupuncture for post-stroke rehabilitation is unsatisfactory and needs improvement.

scholarly journals Impact of risk of bias on the magnitude of treatment effects of randomized controlled trials in implant dentistry

2020 ◽  
Author(s):  
Ruolin Ding ◽  
Wenxin Lu ◽  
Jianru Yi ◽  
Liang Zhang ◽  
Zhihe Zhao
Keyword(s):  
Randomized Controlled Trials ◽  
Treatment Effects ◽  
Permutation Test ◽  
Random Sequence ◽  
Allocation Concealment ◽  
Risk Of Bias ◽  
Selective Reporting ◽  
Controlled Trials ◽  
Randomized Controlled ◽  
Implant Dentistry

Abstract Background: Risk of bias (RoB) could influence the magnitude of treatment effects of randomized controlled trials (RCTs). This study aims to investigate the potential influence of RoB on treatment effects estimates in RCTs in implant dentistry. Methods: The RCTs published in five leading oral implant journals during the recent five years were electronically searched. The RoB was assessed using the Cochrane Collaboration RoB tool. The meta-regression analysis and Monte Carlo permutation test were performed to identify the association between RoB and the magnitude of treatment effects.Results: A considerable amount of studies have high RoB in blinding of participants and personnel, and unclear RoB in allocation concealment and selective reporting. The treatment effects were exaggerated by flaws in allocation concealment for binary outcomes and by deficiencies in random sequence generation and selective reporting for continuous outcomes.Conclusion: RoB frequently exists in RCTs recently published in implant dentistry, which may lead to the exaggeration of treatment effects. Better study design, implementation, and reporting are required for clinical trials in implant dentistry to ensure more reliable evidence.

scholarly journals Use of scratchcards for allocation concealment in a prehospital randomised controlled trial

2018 ◽  
pp. emermed-2018-207881 ◽  
Author(s):  
Leigh Keen ◽  
Jenna Katherine Bulger ◽  
Nigel Rees ◽  
Helen Snooks ◽  
Greg Fegan ◽  
...  
Keyword(s):  
Cost Effectiveness ◽  
Randomised Controlled Trial ◽  
Prehospital Care ◽  
Controlled Trial ◽  
Allocation Concealment ◽  
Prehospital Setting ◽  
Random Allocation ◽  
Registration Number ◽  
Randomised Controlled ◽  
Fascia Iliaca Compartment Block

BackgroundRapid Analgesia for Prehospital Hip Disruption was a small study designed to determine the feasibility of undertaking a randomised controlled trial (RCT) to test the clinical and cost-effectiveness of paramedics administering Fascia Iliaca Compartment Block as early prehospital pain relief to patients with a fractured hip. The objective was to devise a simple and effective method of random allocation concealment suitable for use by paramedics while in the emergency prehospital setting.MethodsScratchcards were produced using scratch-off silver stickers which concealed the trial arm allocation. Paramedics were each allocated a unique range of consecutive numbers, used as both the scratchcard number and the patient’s study ID. The cards were designed to allow the paramedic to write on the incident number, date and signature. A small envelope holding the cards was prepared for each paramedic. The study took place between 28 June 2016 and 31 July 2017 in the Swansea area.ResultsNineteen trial paramedics used 71 scratchcards throughout the study and reported no problems randomly allocating patients using the scratchcards. Five protocol deviations were reported in relation to scratchcard use. On auditing the scratchcards, all unused cards were located, and no evidence of tampering with the silver panel was found.ConclusionParamedics can use scratchcards as a method of randomly allocating patients in trials in prehospital care. In the future, a method that allows only the top card to be selected and a more protective method of storing the cards should be used. Scratchcards can be considered for wider use in RCTs in the emergency prehospital setting.Trial registration numberISRCTN60065373; Post-results.

scholarly journals Assessing the risk of bias in randomized controlled trials in the field of dentistry indexed in the Lilacs (Literatura Latino-Americana e do Caribe em Ciências da Saúde) database

2011 ◽  
Vol 129 (2) ◽  
pp. 85-93 ◽  
Author(s):  
Christiane Alves Ferreira ◽  
Carlos Alfredo Salles Loureiro ◽  
Humberto Saconato ◽  
Álvaro Nagib Atallah
Keyword(s):  
Randomized Controlled Trials ◽  
Research Question ◽  
Allocation Concealment ◽  
Risk Of Bias ◽  
Low Risk ◽  
Controlled Trials ◽  
Level Of Evidence ◽  
Randomized Controlled ◽  
Decision Making Processes ◽  
Meta Analyses

CONTEXT AND OBJECTIVE: Well-conducted randomized controlled trials (RCTs) represent the highest level of evidence when the research question relates to the effect of therapeutic or preventive interventions. However, the degree of control over bias between RCTs presents great variability between studies. For this reason, with the increasing interest in and production of systematic reviews and meta-analyses, it has been necessary to develop methodology supported by empirical evidence, so as to encourage and enhance the production of valid RCTs with low risk of bias. The aim here was to conduct a methodological analysis within the field of dentistry, regarding the risk of bias in open-access RCTs available in the Lilacs (Literatura Latino-Americana e do Caribe em Ciências da Saúde) database. DESIGN AND SETTING: This was a methodology study conducted at Universidade Federal de São Paulo (Unifesp) that assessed the risk of bias in RCTs, using the following dimensions: allocation sequence generation, allocation concealment, blinding, and data on incomplete outcomes. RESULTS: Out of the 4,503 articles classified, only 10 studies (0.22%) were considered to be true RCTs and, of these, only a single study was classified as presenting low risk of bias. The items that the authors of these RCTs most frequently controlled for were blinding and data on incomplete outcomes. CONCLUSION: The effective presence of bias seriously weakened the reliability of the results from the dental studies evaluated, such that they would be of little use for clinicians and administrators as support for decision-making processes.

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