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 (go to Online Submission and view further details in File Formats.)

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.

Contributorship:
Please note the way that we list the names of contributors to papers published in IP. We believe that the definition of authorship, produced by the International Committee of Medical Journal Editors (or Vancouver Group, see www.icmje.org), has some serious flaws.

The current definition of authorship does not make clear who has contributed what to the published study, nor does it clarify who is responsible for the overall content. It also excludes those whose sole but often large contribution has been to collect data.

We now list contributors in two ways. Firstly, we publish a list of authors' names at the beginning of the paper and, secondly, we list contributors (some of whom may not be included as authors) at the end of the paper, giving details of who did what in planning, conducting, and reporting the work.

One or more of these contributors are listed as guarantors of the paper. The guarantor accepts full responsibility for the work and/or the conduct of the study, had access to the data, and controlled the decision to publish.

Contributorship and guarantorship are concepts that were applied first to original papers, and are sometimes hard to define for other articles. Each contributorship statement should make clear who has contributed what to the planning, conduct, and reporting of the work described in the article, and should identify one, or occasionally more, contributor(s) as being responsible for the overall content as guarantor(s). For IP articles that do not report original research please state who had the idea for the article, who performed the literature search, who wrote the article, and who is the guarantor (the contributor who accepts full responsibility for the finished article, had access to any data, and controlled the decision to publish). For non-research articles that include case reports, please also state who identified and/or managed the case(s).

Researchers must determine among themselves the precise nature of each person's contribution, and we encourage open discussion among all participants. See Authorship is dying; long live contributorship.

Authorship:
The uniform requirements for manuscripts submitted to medical journals state that authorship credit should be based only on substantial contribution to: conception and design, or analysis and interpretation of data drafting the article or revising it critically for important intellectual content and final approval of the version to be published.

All these conditions must all be met. Participation solely in the acquisition of funding or the collection of data does not justify authorship.

We want authors to assure us that all authors included on a paper fulfil the criteria of authorship. In addition we want assurance that there is no one else who fulfils the criteria but has not been included as an author.

Alteration to authorship or contributorship:
Any change in authors and/or contributors after initial submission must be approved by all authors. This applies to additions, deletions, change of order to the authors, or contributions being attributed differently. Any alterations must be explained to the editor. The editor may contact any of the authors and/or contributors to ascertain whether they have agreed to any alteration.

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.