If you are submitting a randomised controlled trial please send with your manuscript the following:
The registration number of the trial and the name of the trial registry - in the last line of the papers' structured abstract. Trials that begin enrolment of patients after 1 July 2005 must register in a public trials registry at or before the onset of enrolment to be considered for publication. Trials that began patient enrolment on or before 1 July 2005 must register before 13 September 2005 to be considered for publication. Please see the Statement from the International Committee of Medical Journal Editors.

1. Details of related papers published or submitted for publication.
   
   
   
   1. Copies of related papers should be submitted as supplementary data to help the editor decide how to handle the matter.
   
   
2. Details of previous reviews of the submitted article.
   
   
   
   1. The previous editor's and reviewers' comments should be submitted as supplementary data along with your responses to those comments. Editors encourage authors to submit these previous communications and doing so may expedite the review process.
   
   
3. Whether any of the material could be published as data supplements rather than in the print version of the article.

The title page must contain the following information:

1. The title.
2. The name, postal address, e-mail, telephone, and fax numbers of the corresponding author.
3. The full names, institutions, city, and country of all co-authors.
4. Up to five keywords or phrases suitable for use in an index (it is recommended to use MeSH terms).
5. Word count - excluding title page, references, figures and tables.

The manuscript format must be presented in the following order:

1. Title page
2. Abstract (or summary for case reports)
3. Main text (tables should be inserted where cited in the text; images must be uploaded as separate files)
4. Acknowledgments  Competing interests   Funding
5. References
6. Appendices
   

Provide appropriate headings and subheadings as in the journal. We use the following hierarchy: BOLD CAPS, bold lower case, Plain Text, Italics.

Cite illustrations in numerical order (fig 1, fig 2 etc) as they are first mentioned in the text.

Tables must be embedded where cited in the text.

Images must not be embedded in the text file, but submitted as individual files (view further details in File Formats.)

Articles containing original data concerning the course (prognosis), cause (aetiology), diagnosis, treatment, prevention, or economic analysis of a clinical disorder or an intervention to improve the quality of healthcare must include a structured abstract of no longer than 250 words. The structured abstract should appear on the page following the title page, using the following headings and information.

Objective: State the main question or objective of the study and the major hypothesis tested, if any.

Design: Describe the design of the study, indicating, as appropriate, use of randomisation, blinding, criterion standards for diagnostic tests, temporal direction (retrospective or prospective), and so on.

Setting: Indicate the study setting, including the level of clinical care (eg, primary or tertiary, private practice or institutional).

Patients (or Participants): State selection procedures, entry criteria, and numbers of participants entering and finishing the study.

Interventions (or Assessment of Risk Factors): Describe essential features of any interventions, including their method and duration of administration. For observational studies, clearly outline the independent variables.

Main Outcome Measurements: The primary study outcome measures (dependent variables) should be indicated as planned before data collection began. If the hypothesis being reported was formulated during or after data collection, this fact should be clearly stated.

Results: Report the main findings of the study.

Conclusions: State only those conclusions of the study that are directly supported by data, along with their clinical application (avoiding overgeneralisation) or whether additional study is required before the information should be used in usual clinical settings.

Please note: Equal emphasis must be given to positive and negative findings of equal scientific merit.

Where possible, please name your manuscript and image files as shown below. (Please note: the manuscript ID # appears at the top of each submission page as soon as you start your submission; author refers to the corresponding author's last name.)

1. Your manuscript file should be named as: yr_manuscript id number_author
   (for example: 2005_001234_clark)
2. Your image file should be named as: yr_manuscript id number_F#
   (for example: 2005_001234_F1)

Guidelines on presenting statistics.

Statistical checklist.

Statistical advice for contributors (PDF).

Guidelines on RCTs: CONSORT, QUORUM, MOOSE, STARD, and Economic submissions.

Abbreviations and symbols must be standard and SI units used throughout except for blood pressure values which are reported in mm Hg.

Whenever possible, drugs should be given their approved generic name. Where a proprietary (brand) name is used, it should begin with a capital letter.

Acronyms should be used sparingly and fully explained when first used.

View more detailed style guidelines.