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Why was the CONSORT Statement introduced?

Posted on 5th November 2021 by

Tutorials and Fundamentals

A well designed and accurately implemented randomized controlled trial (RCT) provides the most reliable evidence on the efficacy of healthcare interventions. However, bias may occur due to inadequate methods and poor design, which may result in reporting biased results. This can be misleading in clinical decision-making in healthcare at all levels – from treatment decisions to the formulation of national public health policies. Critical appraisal of the quality of clinical trials is possible only if the design, conduct, and analysis of RCTs are described accurately and completely.

The CONSORT statement?

The term CONSORT stands for Consolidated Standards of Reporting Trials. The CONSORT statement is a 25-item checklist and a flow diagram which is an evidence-based, minimum set of recommendations for reporting randomized trials to alleviate the problems arising from inadequate reporting of RCTs. The CONSORT statement improves the ability to assess validity of clinical trials and also permits better decisions regarding inclusion and possibly weighting of a study within systematic reviews and meta-analyses.

What led to the CONSORT statement being developed?

RCTs are assigned the highest level of evidence. The RCT reports published should be of the highest possible standard for better patient care. It should be able to convey in a transparent manner why the study was undertaken, the study design, study methodology, and analysis of the data.

In 1978, JA Freiman et al carried out a survey of studies conducted between 1960 and 1975. Over 71 RCTs with negative results were published and a majority of them had very few patients to observe moderate or large differences. Allocation concealment was not clearly reported in 61% (n=43) of these RCTs. The results of this survey showed a potential of 25% improvement was possible among 57 of those negative trials and 34 of those trials had a potential of 50% improvement. Many of those studies concluded the test therapy to be as ‘no different from the control’ using inadequate sample size.  This highlighted the importance of proper planning of a clinical trial and the sample size calculation.

As a corrective measure, in the early 1990s, the Standards of Reporting Trials (SORT) group conducted a 2-day workshop, which put forth a new proposal for the reporting of RCTs. This proposal contained 24 essential items that are necessary to be included in the report of a trial.

Another group, the Asilomar Working Group on Recommendations for Reporting of Clinical Trials in the Biomedical Literature, also set a proposal that consisted of a checklist of items that should be included when reporting clinical trials, along with a suggestion that editors add it to the ‘Instructions for Authors’.

In the mid-1990s, these two independent groups participated in a meeting to improve the quality of reports of RCTs by merging the best of SORT and Asilomar proposals into a single, coherent, list of evidence-based recommendations, which led to the publication of the CONSORT statement. This statement was developed by an international group of clinical trialists, statisticians, epidemiologists, and biomedical editors, and was first published in 1996.

The first iteration of the checklist consisted of 21-items that pertain mainly to the methods, results and discussion of an RCT report and key pieces of information necessary to evaluate the internal and external validity of the report.

Further development of the CONSORT statement

In 1999, the original CONSORT checklist was revised to a 22-item checklist, with the latest revised edition being CONSORT 2010 statement, a 25-item checklist (pdf) with accompanying flow diagram (pdf)

The usefulness of CONSORT is enhanced by continuous monitoring of the clinical trials. Modification can be permitted depending on the merits of maintaining or dropping current items and including new items. The checklist is flexible for modifications. For example, the flowchart was modified to accommodate the additional information when Meinert observed that the flow diagram did not provide important information regarding the number of participants who entered each phase of an RCT’s enrolment, treatment allocation, follow-up and data analysis.

The CONSORT statement aims at comprehensive and complete reporting of randomized controlled trials. 

References (pdf)


Jehath Syed

Completed Doctor of Pharmacy and currently pursuing doctoral research at JSS Academy of Higher Education & Research, Mysuru in the area of geriatric medicine to develop a pharmacist comprehensive geriatric care model to promote optimal elderly care and their medical safety. View more posts from Jehath

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