Cluster Trials

The CONSORT extension for Cluster Trials was updated in 2012 to be in-line with CONSORT 2010 and is available for download below. 

The main CONSORT Statement provides recommendations for reporting parallel group randomized trials, in which individual participants are randomly assigned to health care interventions. Cluster trials, however, randomize interventions to groups of patients (e.g., families, medical practices) rather than to individual patients. The main issue associated with their design, conduct, analysis, and interpretation, compared with individually randomized trials, is that two different units of measurement—the cluster and the patient—are used. Each needs to be reported carefully.

Available Downloads

Document Word Format PDF Format
Checklist Download n/a
Flow Diagram jpg n/a
Explanation & Elaboration n/a Download


Campbell MK, Piaggio G, Elbourne DR, Altman DG; for the CONSORT Group. Consort 2010 statement: extension to cluster randomised trials. BMJ. 2012 Sep 4;345:e5661. PMID: 22951546


Extensions of the CONSORT Statement

The main CONSORT Statement is based on the "standard" two-group parallel design. However, there are several variations to the standard trial methodology, including different design aspects (e.g., cluster), interventions (e.g., herbals) and data (e.g., harms).

To help improve the reporting of these trials the main CONSORT Statement has been extended and modified by members of the CONSORT group for application in these various areas. The resulting CONSORT extensions are presented in this section. This list is, by no means, exhaustive; and work is constantly in progress.

Please note that modifications to the CONSORT checklist or flow diagram that are not developed with the involvement of the CONSORT Group do not have permission to name their work "CONSORT".

Some work, however, has been done to modify the CONSORT Statement without the involvement of the Group. These unofficial extensions of the CONSORT Statement can be found here.


Finding the Appropriate Extension

The table below lists the current official extensions of the CONSORT statement.  You can click on each extension to learn more about it or to explore that extension in the checklist viewer application.


Cluster Trials Herbal Medicinal Interventions CONSORT-Outcomes 2022 Checklist (for combined completion of CONSORT 2010) CONSORT-PRO
Non-Inferiority and Equivalence Trials Non-Pharmacologic Treatment Interventions CONSORT-Outcomes 2022 Extension items only (for separate completion of CONSORT 2010 and CONSORT-Outcomes 2022 items) Harms
Pragmatic Trials Acupuncture Interventions  


N-of-1 Trials Chinese Herbal Medicine Formulas   Equity
Pilot and Feasibility Trials  Social and Psychological Interventions   Randomised Crossover Trial Reporting
Within Person Trials      
Multi-Arm Parallel-Group Randomized Trials      
Adaptive Designs