Schulz et al. BMC Medicine 2010, 8:18
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Open Access

CORRESPONDENCECONSORT 2010 Statement: updated guidelines forreporting parallel group randomised trials
Correspondence

Kenneth F Schulz*1, Douglas G Altman2, David Moher3 for the CONSORT Group

Abstract
The CONSORT statement is used worldwide to improve the reporting of randomised controlled trials. Kenneth Schulz
and colleagues describe the latest version, CONSORT 2010, which updates the reporting guideline based on new
methodological evidence and accumulating experience.
To encourage dissemination of the CONSORT 2010 Statement, this article is freely accessible on bmj.com and will also
be published in the Lancet, Obstetrics and Gynecology, PLoS Medicine, Annals of Internal Medicine, Open Medicine,
Journal of Clinical Epidemiology, BMC Medicine, and Trials.
Introduction
Randomised controlled trials, when appropriately
designed, conducted, and reported, represent the gold
standard in evaluating healthcare interventions. However, randomised trials can yield biased results if they lackmethodological rigour [1]. To assess a trial accurately,
readers of a published report need complete, clear, andtransparent information on its methodology and findings. Unfortunately, attempted assessments frequently
fail because authors of many trial reports neglect to provide lucid and complete descriptions of that critical information [2-4].
That lack of adequate reporting fuelled the development of the original CONSORT (Consolidated Standardsof Reporting Trials) statement in 1996 [5] and its revision
five years later [6-8]. While those statements improved
the reporting quality for some randomised controlled trials, [9,10] many trial reports still remain inadequate [2].
Furthermore, new methodological evidence and additional experience has accumulated since the last revisionin 2001. Consequently, we organised a CONSORT Group
meeting to update the 2001 statement [6-8]. We introduce here the result of that process, CONSORT 2010.
Intent of CONSORT 2010
The CONSORT 2010 Statement is this paper including
the 25 item checklist in the table (Table 1) and the flow
diagram (Figure 1). It provides guidance for reporting all* Correspondence: kschulz@fhi.org
1 Family Health International, Research Triangle Park, NC 27709, USA

Full list of author information is available at the end of the article

randomised controlled trials, but focuses on the mostcommon design type-individually randomised, twogroup, parallel trials. Other trial designs, such as cluster
randomised trials and non-inferiority trials, require varying amounts of additional information. CONSORT
extensions for these designs, [11,12] and other CONSORT products, can be found through the CONSORT
website http://www.consort-statement.org. Along with
the CONSORT statement, we have updated the explanation and elaboration article, [13] which explains the inclusion of each checklist item, provides methodologicalbackground, and gives published examples of transparent
reporting.
Diligent adherence by authors to the checklist items
facilitates clarity, completeness, and transparency ofreporting. Explicit descriptions, not ambiguity or omission, best serve the interests of all readers. Note that the
CONSORT 2010 Statement does not include recommendations for designing, conducting, and analysing trials. It
solely addresses the reporting of what was done and what
was found.
Nevertheless, CONSORT does indirectly affect designand conduct. Transparent reporting reveals deficiencies
in research if they exist. Thus, investigators who conduct
inadequate trials, but who must transparently report,
should not be able to pass through the publication process without revelation of their trial's inadequacies. Thatemerging reality should provide impetus to improved
trial design and conduct in the future, a secondary indirect goal of our work. Moreover, CONSORT can help
researchers in designing their trial.

© 2010 Schulz et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons

BioMed Central Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction inany medium, provided the original work is properly cited.

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Table 1: CONSORT 2010 checklist of information to include when reporting a randomised trial*
Section/Topic

Item No

Checklist item

Title and abstract
1a

Identification as a randomised
trial in the title

1bStructured summary of trial
design, methods, results, andconclusions (for specificguidance see CONSORT for
abstracts [21,31])

2a

Scientific background andexplanation of rationale

2b

Specific objectives or
hypotheses

3aDescription of trial design(such as parallel, factorial)
including allocation ratio

3b

Important changes tomethods after trial
commencement (such as
eligibility criteria), withreasons

4a

Eligibility criteria forparticipants

4b

Settings and locations where
the data were collectedInterventions

5

The interventions for eachgroup with sufficient details toallow replication, including
how and when they wereactually administered

Outcomes

6aCompletely defined prespecified primary andsecondary outcome
measures, including how andwhen they were assessed6b

Any changes to trial outcomes
after the trial commenced,
with reasons

7a

How sample size wasdetermined

7b

When applicable, explanationof any interim analyses andstopping guidelines

8a

Method used to generate therandom allocation sequence

8b

Type of randomisation; detailsof any restriction (such as
blocking and block size)

Introduction
Background and objectives

Methods
Trial design

Participants

Sample size

Randomisation:
Sequence generation

Reported on page No

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Table 1: CONSORT 2010 checklist of information to include when reporting a randomised trial* (Continued)
Allocation concealment
mechanism

9

Mechanism used to
implement the random
allocation sequence (such as
sequentially numberedcontainers), describing any
steps taken to conceal thesequence until interventions
were assigned

Implementation

10

Who generated the random
allocation sequence, who
enrolled participants, and who
assigned participants tointerventions

11a

If done, who was blinded after
assignment to interventions(for example, participants,
care providers, those
assessing outcomes) and how

11b

If relevant, description of thesimilarity of interventions

12a

Statistical methods used tocompare groups for primaryand secondary outcomes

12b

Methods for additional
analyses, such as subgroup
analyses and adjusted
analyses

13a

For each group, the numbersof participants who wererandomly assigned, received
intended treatment, and wereanalysed for the primary
outcome13b

For each group, losses andexclusions after
randomisation, together withreasons

14a

Dates defining the periods ofrecruitment and follow-up

14b

Why the trial ended or was
stoppedBaseline data

15

A table showing baseline
demographic and clinicalcharacteristics for each group

Numbers analysed

16

For each group, number ofparticipants (denominator)
included in each analysis andwhether the analysis was byoriginal assigned groups

Outcomes and estimation

17a

For each primary andsecondary outcome, resultsfor each group, and theestimated effect size and its
precision (such as 95%
confidence interval)

Blinding

Statistical methods

Results
Participant flow (a diagram isstrongly recommended)

Recruitment

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Table 1: CONSORT 2010 checklist of information to include when reporting a randomised trial* (Continued)
17b

For binary outcomes,
presentation of both absoluteand relative effect sizes isrecommended

Ancillary analyses

18

Results of any other analyses
performed, including
subgroup analyses andadjusted analyses,
distinguishing pre-specified
from exploratory

Harms

19

All important harms orunintended effects in eachgroup (for specific guidance
see CONSORT for harms [28])Limitations

20

Trial limitations, addressing
sources of potential bias,
imprecision, and, if relevant,multiplicity of analyses

Generalisability

21

Generalisability (external
validity, applicability) of thetrial findingsInterpretation

22

Interpretation consistent withresults, balancing benefits andharms, and considering otherrelevant evidence

Registration

23

Registration number andname of trial registry

Protocol24

Where the full trial protocol
can be accessed, if available

Funding

25

Sources of funding and othersupport (such as supply of
drugs), role of funders

Discussion

Other information*We strongly recommend reading this statement in conjunction with the CONSORT 2010 Explanation and Elaboration [13] for important
clarifications on all the items. If relevant, we also recommend reading CONSORT extensions for cluster randomised trials [11], non-inferiority
and equivalence trials [12], non-pharmacological treatments [32], herbal interventions [33], and pragmatic trials [34]. Additional extensions
are forthcoming: for those and for up to date references relevant to this checklist, see http://www.consort-statement.org.

Background to CONSORT
Efforts to improve the reporting of randomised controlled trials accelerated in the mid-1990s, spurred partly
by methodological research. Researchers had shown formany years that authors reported such trials poorly, andempirical evidence began to accumulate that some poorly
conducted or poorly reported aspects of trials were associated with bias [14]. Two initiatives aimed at developing
reporting guidelines culminated in one of us (DM) andDrummond Rennie organising the first CONSORT statement in 1996 [5]. Further methodological research on
similar topics reinforced earlier findings [15] and fed into
the revision of 2001 [6-8]. Subsequently, the expanding
body of methodological research informed the refinement of CONSORT 2010. More than 700 studies com-prise the CONSORT database (located on the
CONSORT website), which provides the empirical evidence to underpin the CONSORT initiative.
Indeed, CONSORT Group members continually monitor the literature. Information gleaned from these efforts
provides an evidence base on which to update the CONSORT statement. We add, drop, or modify items based onthat evidence and the recommendations of the CONSORT Group, an international and eclectic group of clinical trialists, statisticians, epidemiologists, and biomedical
editors. The CONSORT Executive (KFS, DGA, DM)
strives for a balance of established and emerging
researchers. The membership of the group is dynamic. As
our work expands in response to emerging projects andneeded expertise, we invite new members to contribute.

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Figure 1 Flow diagram of the progress through the phases of a parallel randomised trial of two groups (that is, enrolment, intervention
allocation, follow-up, and data analysis).

As such, CONSORT continually assimilates new ideas
and perspectives. That process informs the continually
evolving CONSORT statement.
Over time, CONSORT has garnered much support.
More than 400 journals, published around the world andin many languages, have explicitly supported the CONSORT statement. Many other healthcare journals support
it without our knowledge. Moreover, thousands more
have implicitly supported it with the endorsement of the
CONSORT statement by the International Committee ofMedical Journal Editors http://www.icmje.org. Other
prominent editorial groups, the Council of Science Editors and the World Association of Medical Editors, officially support CONSORT. That support seems
warranted: when used by authors and journals, CONSORT seems to improve reporting [9].

Development of CONSORT 2010
Thirty one members of the CONSORT 2010 Group met
in Montebello, Canada, in January 2007 to update the2001 CONSORT statement. In addition to the accumulating evidence relating to existing checklist items, several
new issues had come to prominence since 2001. Someparticipants were given primary responsibility for aggre-

gating and synthesising the relevant evidence on a particular checklist item of interest. Based on that evidence, thegroup deliberated the value of each item. As in prior
CONSORT versions, we kept only those items deemedabsolutely fundamental to reporting a randomised controlled trial. Moreover, an item may be fundamental to atrial but not included, such as approval by an institutional
ethical review board, because funding bodies strictly
enforce ethical review and medical journals usually
address reporting ethical review in their instructions for
authors. Other items may seem desirable, such as reporting on whether on-site monitoring was done, but a lack of
empirical evidence or any consensus on their value cautions against inclusion at this point. The CONSORT 2010
Statement thus addresses the minimum criteria, althoughthat should not deter authors from including other information if they consider it important.
After the meeting, the CONSORT Executive convened
teleconferences and meetings to revise the checklist.
After seven major iterations, a revised checklist was distributed to the larger group for feedback. With that feedback, the executive met twice in person to consider all thecomments and to produce a penultimate version. That
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which was then distributed to the group for feedback.
After consideration of their comments, the executive finalised the statement.
The CONSORT Executive then drafted an updated
explanation and elaboration manuscript, with assistancefrom other members of the larger group. The substanceof the 2007 CONSORT meeting provided the material forthe update. The updated explanation and elaboration
manuscript was distributed to the entire group for additions, deletions, and changes. That final iterative process
converged to the CONSORT 2010 Explanation and Elaboration [13].

Changes in CONSORT 2010
The revision process resulted in evolutionary, not revolutionary, changes to the checklist (Table 1), and the flow
diagram was not modified except for one word (Figure 1).
Moreover, because other reporting guidelines augmenting the checklist refer to item numbers, we kept the existing items under their previous item numbers except forsome renumbering of items 2 to 5. We added additional
items either as a sub-item under an existing item, anentirely new item number at the end of the checklist, or(with item 3) an interjected item into a renumbered segment. We have summarised the noteworthy generalchanges in Appendix 1 and specific changes in Appendix
2. The CONSORT website contains a side by side comparison of the 2001 and 2010 versions.
Implications and limitations
We developed CONSORT 2010 to assist authors in writing reports of randomised controlled trials, editors andpeer reviewers in reviewing manuscripts for publication,and readers in critically appraising published articles. The
CONSORT 2010 Explanation and Elaboration provides
elucidation and context to the checklist items. We
strongly recommend using the explanation and elaboration in conjunction with the checklist to foster complete,
clear, and transparent reporting and aid appraisal of published trial reports.
CONSORT 2010 focuses predominantly on the twogroup, parallel randomised controlled trial, which
accounts for over half of trials in the literature [2]. Mostof the items from the CONSORT 2010 Statement, however, pertain to all types of randomised trials. Nevertheless, some types of trials or trial situations dictate theneed for additional information in the trial report. Whenin doubt, authors, editors, and readers should consult the
CONSORT website for any CONSORT extensions,
expansions (amplifications), implementations, or otherguidance that may be relevant.
The evidence based approach we have used for CONSORT also served as a model for development of otherreporting guidelines, such as for reporting systematic

Page 6 of 9reviews and meta-analyses of studies evaluating interventions [16], diagnostic studies [17], and observational studies [18]. The explicit goal of all these initiatives is toimprove reporting. The Enhancing the Quality andTransparency of Health Research (EQUATOR) Network
will facilitate development of reporting guidelines andhelp disseminate the guidelines: http://www.equator-network.org provides information on all reporting guidelines
in health research.
With CONSORT 2010, we again intentionally declined
to produce a rigid structure for the reporting of randomised trials. Indeed, SORT [19] tried a rigid format,
and it failed in a pilot run with an editor and authors [20].
Consequently, the format of articles should abide by journal style, editorial directions, the traditions of theresearch field addressed, and, where possible, author
preferences. We do not wish to standardise the structureof reporting. Authors should simply address checklist
items somewhere in the article, with ample detail andlucidity. That stated, we think that manuscripts benefit
from frequent subheadings within the major sections,especially the methods and results sections.
CONSORT urges completeness, clarity, and transparency of reporting, which simply reflects the actual trial
design and conduct. However, as a potential drawback, areporting guideline might encourage some authors toreport fictitiously the information suggested by the guidance rather than what was actually done. Authors, peer
reviewers, and editors should vigilantly guard against that
potential drawback and refer, for example, to trial protocols, to information on trial registers, and to regulatory
agency websites. Moreover, the CONSORT 2010 Statement does not include recommendations for designingand conducting randomised trials. The items should elicit
clear pronouncements of how and what the authors did,
but do not contain any judgments on how and what theauthors should have done. Thus, CONSORT 2010 is notintended as an instrument to evaluate the quality of atrial. Nor is it appropriate to use the checklist to construct a "quality score."
Nevertheless, we suggest that researchers begin trials
with their end publication in mind. Poor reporting allows
authors, intentionally or inadvertently, to escape scrutinyof any weak aspects of their trials. However, with wide
adoption of CONSORT by journals and editorial groups,
most authors should have to report transparently allimportant aspects of their trial. The ensuing scrutiny
rewards well conducted trials and penalises poorly conducted trials. Thus, investigators should understand the
CONSORT 2010 reporting guidelines before starting a
trial as a further incentive to design and conduct their trials according to rigorous standards.
CONSORT 2010 supplants the prior version publishedin 2001. Any support for the earlier version accumulated

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from journals or editorial groups will automaticallyextend to this newer version, unless specifically requested
otherwise. Journals that do not currently support CONSORT may do so by registering on the CONSORT website. If a journal supports or endorses CONSORT 2010, it
should cite one of the original versions of CONSORT2010, the CONSORT 2010 Explanation and Elaboration,and the CONSORT website in their "Instructions toauthors." We suggest that authors who wish to cite CONSORT should cite this or another of the original journalversions of CONSORT 2010 Statement, and, if appropriate, the CONSORT 2010 Explanation and Elaboration[13]. All CONSORT material can be accessed through theoriginal publishing journals or the CONSORT website.
Groups or individuals who desire to translate the CONSORT 2010 Statement into other languages should first
consult the CONSORT policy statement on the website.
We emphasise that CONSORT 2010 represents an
evolving guideline. It requires perpetual reappraisal and,if necessary, modifications. In the future we will further
revise the CONSORT material considering comments,
criticisms, experiences, and accumulating new evidence.
We invite readers to submit recommendations via the
CONSORT website.

Appendix 1: Noteworthy general changes in
CONSORT 2010 Statement• We simplified and clarified the wording, such as initems 1, 8, 10, 13, 15, 16, 18, 19, and 21• We improved consistency of style across the items by
removing the imperative verbs that were in the 2001 version• We enhanced specificity of appraisal by breaking
some items into sub-items. Many journals expect authors
to complete a CONSORT checklist indicating where in
the manuscript the items have been addressed. Experience with the checklist noted pragmatic difficulties when
an item comprised multiple elements. For example, item
4 addresses eligibility of participants and the settings andlocations of data collection. With the 2001 version, an
author could provide a page number for that item on the
checklist, but might have reported only eligibility in thepaper, for example, and not reported the settings andlocations. CONSORT 2010 relieves obfuscations andforces authors to provide page numbers in the checklist
for both eligibility and settings.
Appendix 2: Noteworthy specific changes in
CONSORT 2010 Statement
Item 1b (title and abstract)-We added a sub-item on providing a structured summary of trial design, methods,
results, and conclusions and referenced the CONSORT
for abstracts article [21].

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Item 2b (introduction)-We added a new sub-item (formerly item 5 in CONSORT 2001) on "Specific objectives
or hypotheses"
Item 3a (trial design)-We added a new item including
this sub-item to clarify the basic trial design (such as parallel group, crossover, cluster) and the allocation ratio
Item 3b (trial design)-We added a new sub-item that
addresses any important changes to methods after trial
commencement, with a discussion of reasons
Item 4 (participants)-Formerly item 3 in CONSORT
2001
Item 5 (interventions)-Formerly item 4 in CONSORT
2001. We encouraged greater specificity by stating that
descriptions of interventions should include "sufficientdetails to allow replication"[3]Item 6 (outcomes)-We added a sub-item on identifying
any changes to the primary and secondary outcome (endpoint) measures after the trial started. This followed fromempirical evidence that authors frequently provide analyses of outcomes in their published papers that were not
the prespecified primary and secondary outcomes intheir protocols, while ignoring their prespecified outcomes (that is, selective outcome reporting) [4,22]. We
eliminated text on any methods used to enhance the quality of measurements
Item 9 (allocation concealment mechanism)-We
reworded this to include mechanism in both the report
topic and the descriptor to reinforce that authors shouldreport the actual steps taken to ensure allocation concealment rather than simply report imprecise, perhaps banal,
assurances of concealment
Item 11 (blinding)-We added the specification of how
blinding was done and, if relevant, a description of thesimilarity of interventions and procedures. We also eliminated text on "how the success of blinding (masking) was
assessed" because of a lack of empirical evidence supporting the practice as well as theoretical concerns about thevalidity of any such assessment [23,24]
Item 12a (statistical methods)-We added that statisticalmethods should also be provided for analysis of secondary outcomes
Sub-item 14b (recruitment)-Based on empiricalresearch, we added a sub-item on "Why the trial ended or
was stopped" [25]Item 15 (baseline data)-We specified "A table" to clarify
that baseline and clinical characteristics of each group are
most clearly expressed in a table
Item 16 (numbers analysed)-We replaced mention of"intention to treat" analysis, a widely misused term, by amore explicit request for information about retaining
participants in their original assigned groups [26]Sub-item 17b (outcomes and estimation)-For appropriate clinical interpretability, prevailing experience suggested the addition of "For binary outcomes, presentation

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of both relative and absolute effect sizes is recommended"[27]
Item 19 (harms)-We included a reference to the CONSORT paper on harms [28]Item 20 (limitations)-We changed the topic from "Interpretation" and supplanted the prior text with a sentence
focusing on the reporting of sources of potential bias andimprecision
Item 22 (interpretation)-We changed the topic from
"Overall evidence." Indeed, we understand that authors
should be allowed leeway for interpretation under thisnebulous heading. However, the CONSORT Group
expressed concerns that conclusions in papers frequently
misrepresented the actual analytical results and thatharms were ignored or marginalised. Therefore, wechanged the checklist item to include the concepts ofresults matching interpretations and of benefits beingbalanced with harms
Item 23 (registration)-We added a new item on trial registration. Empirical evidence supports the need for trial
registration, and recent requirements by journal editors
have fostered compliance [29]Item 24 (protocol)-We added a new item on availabilityof the trial protocol. Empirical evidence suggests that
authors often ignore, in the conduct and reporting of
their trial, what they stated in the protocol [4,22]. Hence,
availability of the protocol can instigate adherence to theprotocol before publication and facilitate assessment ofadherence after publication
Item 25 (funding)-We added a new item on funding.
Empirical evidence points toward funding source sometimes being associated with estimatedeatment effects [30]Competing interests
Uniform disclosure of potential conflicts of interest: all authors have completed
the ICMJE unified competing interest form at http://www.icmje.org/
coi_disclosure.pdf (available from the corresponding author) and declare (1)DM received grants for this work from Johnson & Johnson, BMJ, and American
Society for Clinical Oncology; KFS and DGA received support for travel to meetings for this work from Johnson & Johnson, BMJ, and American Society for Clinical Oncology; (2) KFS and DA had travel expenses reimbursed by the EQUATOR
Network; KFS has received honoraria for delivering educational presentations
for the American Board of Obstetrics and Gynecology Foundation for Excellence in Women's Health Care, Ortho-McNeil Janssen Scientific Affairs, and theAmerican College of Obstetrics and Gynecology; and has done consultancy for
Wyeth. All authors also declare (3) no spouses, partners, or children with relationships with commercial entities that might have an interest in the submitted work; (4) no non-financial interests that may be relevant to the submitted
work.
Authors' contributions
KFS, DM, and DGA participated in meetings and regular conference calls,
planned the CONSORT 2007 meeting at Montebello, developed the agenda,
prepared background research, identified and invited participants, contributed
to the CONSORT meeting, drafted the manuscript, and, after critical review by
the CONSORT Group, finalised the text of the manuscript. Members of the
CONSORT Group attended the meeting, except for those noted below, andprovided input on and review of the revised checklist and text of this article.
Some members also prepared background material.

Page 8 of 9

Acknowledgements
The CONSORT Group contributors to CONSORT 2010: DG Altman, Centre for
Statistics in Medicine, University of Oxford; Virginia Barbour, PLoS Medicine;Jesse A Berlin, Johnson & Johnson Pharmaceutical Research and Development,
USA; Isabelle Boutron, University Paris 7 Denis Diderot, Assistance Publique desHôpitaux de Paris, INSERM, France; PJ Devereaux, McMaster University, Canada;
Kay Dickersin, Johns Hopkins Bloomberg School of Public Health, USA; Diana
Elbourne, London School of Hygiene & Tropical Medicine; Susan Ellenberg,
University of Pennsylvania School of Medicine, USA; Val Gebski, University ofSydney, Australia; Steven Goodman, Journal of the Society for Clinical Trials, USA;Peter C Gøtzsche, Nordic Cochrane Centre, Denmark; Trish Groves, BMJ; Steven
Grunberg, American Society of Clinical Oncology, USA; Brian Haynes, McMaster
University, Canada; Sally Hopewell, Centre for Statistics in Medicine, Universityof Oxford; Astrid James, Lancet; Peter Juhn, Johnson & Johnson, USA; Philippa
Middleton, University of Adelaide, Australia; Don Minckler, University of California Irvine, USA; D Moher, Ottawa Methods Centre, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Canada; Victor M Montori,
Knowledge and Encounter Research Unit, Mayo Clinic College of Medicine,
USA; Cynthia Mulrow, Annals of Internal Medicine, USA; Stuart Pocock, London
School of Hygiene & Tropical Medicine; Drummond Rennie, JAMA, USA; David L
Schriger, Annals of Emergency Medicine, USA; KF Schulz, Family Health International, USA; Iveta Simera, EQUATOR Network; Elizabeth Wager, Sideview.
Contributors to CONSORT 2010 who did not attend the Montebello meeting:Mike Clarke, UK Cochrane Centre; Gordon Guyatt, McMaster University, Canada.
Funding: We received financial support from United Kingdom National Institute for Health Research and the Medical Research Council; Canadian Institutesof Health Research; Presidents Fund, Canadian Institutes of Health Research;
Johnson & Johnson; BMJ; and the American Society for Clinical Oncology. DGA
is supported by Cancer Research UK, DM by a University of Ottawa Research
Chair, and KFS by Family Health International. None of the sponsors had any
involvement in the planning, execution, or writing of the CONSORT documents. Additionally, no funder played a role in drafting the manuscript.
In order to encourage dissemination of the CONSORT 2010 Statement, thisarticle is freely accessible on bmj.com and will also be published in the Lancet,
Obstetrics and Gynecology, PLoS Medicine, Annals of Internal Medicine, Open
Medicine, Journal of Clinical Epidemiology, BMC Medicine, and Trials. The
authors jointly hold the copyright of this article. For details on further use, see
the CONSORT website http://www.consort-statement.org.
Author Details
1Family Health International, Research Triangle Park, NC 27709, USA, 2Centre

for Statistics in Medicine, University of Oxford, Wolfson College, Oxford, UK and
3Ottawa Methods Centre, Clinical Epidemiology Program, Ottawa Hospital
Research Institute, Department of Epidemiology and Community Medicine,
University of Ottawa, Ottawa, Canada
Received: 17 February 2010 Accepted: 24 March 2010
Published: 24 March 2010
©
This
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2010
articleisMedicine
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Ltd.the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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Pre-publication history
The pre-publication history for this paper can be accessed here:
http://www.biomedcentral.com/1741-7015/8/18/prepub
doi: 10.1186/1741-7015-8-18
Cite this article as: Schulz et al., CONSORT 2010 Statement: updated guidelines for reporting parallel group randomised trials BMC Medicine 2010, 8:18