The Journal of Clinical Epidemiology aims at promoting the quality of clinical epidemiologic and patient-oriented health services research through the following: Advancement and application of innovative methods of conducting and presenting primary research; Synthesizing research results; Disseminating results; And translating results into optimal clinical practice with special attention to the training of new generations of scientists and clinical practice leaders.

Contributions are welcomed from any pertinent source but should be written clearly enough to be understood by scholarly clinical readers and clinical researchers. Pertinent symposia and reviews will be considered for publication.

The Journal of Clinical Epidemiology does not accept articles reporting material that has been published at any length elsewhere. The author(s) should state, in a covering letter, that the submitted material has not been published and is not under consideration for publication elsewhere. If any form of preliminary publication other than an abstract of not more than 400 words has occurred or is being considered, a reprint or manuscript should accompany the material submitted to the Journal.

Support and Financial Disclosure Declaration
As a scientific forum for research and commentary, the Journal is willing to consider submissions from any appropriate source, and to review them according to pertinent scientific and editorial standards. Since the text itself may not always allow evaluators and readers to discern possible conflicts of interest, the second page of each manuscript should acknowledge research support (from funding agencies or industry) and disclose any potential financial conflicts of interest for each author. Any meaningful affiliation or involvement, either direct or indirect, with any organization or entity with a direct financial interest in the subject matter or materials discussed (e.g., employment, consultancies, grants, honoraria) must be disclosed. All relevant sources of support and funding for each author must also be included in summary in an Acknowledgments section of the manuscript. If no financial conflict of interest is identified, 'none' should be written next to the author's name.

Open access
This journal offers you the option of making your article freely available to all via the www.jclinepi.com and ScienceDirect platforms. To prevent any conflict of interest, you can only make this choice after receiving notification that your article has been accepted for publication. The fee of $3,000 excludes taxes and other potential author fees such as color charges. In some cases, institutions and funding bodies have entered into agreement with Elsevier to meet these fees on behalf of their authors. Details of these agreements are available at http://www.elsevier.com/fundingbodies. Authors of accepted articles, who wish to take advantage of this option, should complete and submit the order form (available at http://www.elsevier.com/locate/openaccessform.pdf). Whatever access option you choose, you retain many rights as an author, including the right to post a revised personal version of your article on your own website. More information can be found here: http://www.elsevier.com/authorsrights.

Submission Process
The Journal of Clinical Epidemiology uses an online submission and peer-review system. Please visit http://ees.elsevier.com/jce and follow the onscreen instructions for all submissions. If you have questions during the process, please contact the JCE Editorial Offices at kimluyten@hag.unimaas.nl or ltugwell@uottawa.ca. Manuscripts must be written in English. Please note that an editable file is needed for production purposes, in the case that your manuscript is accepted; original source files, not PDF files, are required.

• In an accompanying letter, authors should state that the manuscript, or parts of it, have not been and will not be submitted elsewhere for publication.
• Authors are obliged to provide the contact details (including e-mail addresses) of the three or more potential peer reviewers for their manuscript. These should be experts in their field of study, who will be able to provide an objective assessment of the manuscript. Any suggested peer reviewers should not have published with any of the authors of the manuscript within the past 5 years and should not be members of the same research institution. Members of the Editorial Board of the journal can be nominated. Suggested reviewers will be considered alongside potential reviewers identified by their publication record or recommended by Editorial Board members.
• Authors’ submission items include a cover letter, suggested reviewers, the manuscript (including title page, abstract, manuscript text, references, and table/figure legends), tables, and figures. Note: A “Letter to the Editor” does not require an abstract.
• Supplemental information such as extensive statistical tables, computer algorithms and original questionnaires will not be included in the print version of the Journal of Clinical Epidemiology, but will be made available on the web site; the link will be provided in the printed article. Please note: supplemental pieces will not be copy edited. Authors should state explicitly which tables and figures are web-only material.
• Revised manuscripts should also be accompanied by a unique file (separate from the covering letter) with responses to reviewers’ comments.
• The preferred order of files is as follows: cover letter, suggested reviewers, response to reviews (revised manuscripts only), manuscript file(s), table(s), figure(s).
• Files should be labelled with appropriate and descriptive file names (e.g., SmithText.doc, Fig1.eps, Table3.doc).
• Upload text, tables and graphics as separate files.
• Do not import figures or tables into the next document.
• Complete instructions for electronic artwork submission can be found here: www.elsevier.com/wps/find/authorsview.authors/authorartworkinstructions.
• Once the submission files are uploaded, the system automatically generates an electronic (PDF) proof, which is then used for reviewing.
• All correspondence, including the Editor’s decision and request for revisions, will be by e-mail.
• Authors who are unable to provide an electronic version or have other circumstances that prevent online submission must contact either our Ottawa or Maastricht editorial office at the address listed below, prior to submission to discuss alternate options. The Publisher and Editors regret that they are not able to consider submissions that do not follow these procedures.

André Knottnerus
Editor
Journal of Clinical EpidemiologyDepartment of General Practice, PO Box 616, 6200 MD Maastricht, The Netherlands
Tel.: +31-43-388-2322, Fax: +31-43-367-1458, E-mail: kim.luyten@maastrichtuniversity.nl, Website: http://www.jclinepi.com

Peter Tugwell
Editor
Journal of Clinical Epidemiology
Centre for Global Health
1 Stewart Street Ottawa, ON K1N 6N5, Canada
E-mail: ltugwell@uottawa.ca

Manuscripts and Abstracts
Manuscripts should be typewritten and double spaced. Author(s) should retain the original to facilitate revisions or resubmissions. The letter of submission should identify an address for the corresponding author, and where possible, the author's fax number, e-mail address, and telephone number.

Authorship. In accordance with the International Committee of Medical Journal Editors (ICMJE) recommendations which are available at www. icmje.org, all authors must have a significant role in the manuscript. This means that all 3 of the following conditions must be met:
• The individual made a substantial contribution to conception and design of the study, to data acquisition, or to data analysis and interpretation; and
• The individual wrote the article and/or revised the article for important intellectual content; and
• The individual approved the final version of the submitted manuscript. Note: If revision is requested, the individual must also approve any subsequent versions submitted to the journal. All individuals who contributed to the writing of the manuscript must be identified either as an author or in the acknowledgements section of the manuscript. In particular, if medical writer(s)/editor(s) have been involved, their role must be explicitly acknowledged, and their affiliation/source of funding must be listed. At the editor’s discretion, a description of the contribution of each individual listed as an author may be requested by the journal. Article Titles. JCE has adopted the editorial policy of “more informative titles” (MITs) that crisply and concisely tell our readers what our authors found in their research. A MIT states the study type and summarizes its key findings, using the past tense for individual studies and the present tense for systematic reviews. Although we are ready to assist authors in generating MITs for their work, we encourage them to submit draft MITs with their original submissions.

Abstracts. Each original article must have an abstract/summary not exceeding 200 words. Abstracts must be structured with the following headings: Objective, Study Design and Setting, Results, and Conclusion. Double-space abstracts, and print them on a separate page. Abstracts not in compliance with this format will be returned to the authors for revision. The bottom of the abstract page should list six key words (index-appropriate terms), a running title and a word count. Commentaries do not require abstracts.

What is new? Authors are asked to provide a text box entitled “What is new?” that summarized what this paper adds to the existing literature, with up to 5 items/points addressing the following areas:

- key findings
- what this adds to what is known
- what is the implication, what should change now

Please place this box below the abstract but before the introduction of your paper.

Research Articles
The Journal endorses the World Health Organization Standards for registration of all human medical research (http://www.who.int/ictrp). JCE considers original papers reporting results of clinical trials if they have been registered in a clinical trial registry. Authors are asked to provide registration details in the submission letter and the manuscript.

Length of Articles
The following are guidelines for various article lengths:

• Reviews and Original Articles - 3,000 to 5,000 words
• Letters - 500 words
• Brief Reports - 1,500 words
• Commentaries - 2,500 words.

Correct Use of Statistical Methods
The correct use of statistical methods is paramount for a proper interrogation and interpretation of study data. There are several checklists available that can be used to help authors. One checklist found to be helpful is from the Department of Biostatistics, Vanderbilt University School of Medicine (http://biostat.mc.vanderbilt.edu/ManuscriptChecklist) and we refer authors submitting articles to the JCE to this checklist. The list covers general statistical problems, filtering, missing data, multiple comparison problems, multivariate modeling issues, use of imprecise language, graphics, tables, and other areas.

References
All references should be to publications that are readily available or in press, avoiding personal communications, presentations at meetings, and manuscripts submitted but not yet in press. Citations should be placed at the end of each article (not as footnotes on each page), and should be numbered consecutively in the text, enclosed in square brackets on the lines of writing (not as superscript numbers). At the end of the article, references should be listed in the numerical order in which they are cited. The references should be typed, double-spaced, and should conform to the styles noted either in the ‘Vancouver Convention’ or by Index Medicus or the Council of Biology Editors Style Manual (available from http://www.icmje.org or the American Institute of Biological Sciences, 1401Wilson Boulevard, Arlington, VA 22209, U.S.A.). Ultimate responsibility for accuracy of citations rests with the author(s).

The publisher has requirements for electronic files in which text citations are properly matched to the reference list. Please review any revised manuscript for discrepancies (especially with numbering) and correct the references appropriately.

Examples

(i) Book chapter
Temple R. Dose-response and registration of new drugs. In: Lasagna L, Erill S, Naranjo CA, Eds. Dose-Response Relationships in Clinical Pharmacology. Amsterdam: Elsevier;1989:145-170.

(ii) Book
Kramer MS. Clinical Epidemiology and Biostatistics: a Primer for Clinical Investigators and Decision-makers. Berlin: Springer; 1988.

(iii) Journal
Garraway WM, Whisnant JP, Kurland LT, O'Fallon WM. Changing pattern of cerebral infarction: 1945-1974. Stroke 1979;10:657-663.

(iv) Miscellaneous
Ontario Ministry of Health. Schedule of Benefits, Ontario Health Insurance Plan. Kingston, Ontario: Ontario Ministry of Health; April 1987.

Abbreviations, Symbols and Nomenclature
Well-known abbreviations (e.g. DNA, EKG) may be used without definition; all others must be defined when first used. Units of measurement should be used in accordance with current custom and acceptability. Generic names of drugs are preferred; a proprietary name may be used if its generic equivalent is identified.

Figures and Tables
Figures and Tables accompanying manuscripts should not exceed a total of 6 and should be numbered and provided with suitable legends, in a separate electronic file. Authors should indicate on the manuscript the appropriate positions of the tables and figures.

Tables: Type each table on a separate page. Do not insert vertical lines in tables. Include a title for each table. Number tables consecutively within the manuscript (Table 1, Table 2, Table 3, etc.). Use asterisks (*, **, ***) for P values and otherwise use standard citation superscript symbols (*, †, ‡, § . . .). Authors should place footnotes in order, reading from left to right and top to bottom, and should begin a new series of footnotes for each table. Footnotes should not appear in table titles. Lengthy tables should be avoided as they might be too large to be reproduced in print. However, they may be submitted as a web-only appendix.

Figures: Illustrations include charts, drawings, graphs, and photographs. Charts, drawings and graphs must be computer-generated and should use a Sans-serif typeface (e.g., Arial). Number figures consecutively in the order they are to appear in the text (e.g., Fig. 1, Fig. 2, Fig. 3, etc.). Figures should be uploaded as separate files, not embedded in the manuscript file. TIFF, EPS, or PDF are the preferred file formats. MS Office files (Word, Excel, and PowerPoint) are also accepted. The following image file formats are not acceptable because they are low resolution: JPG, GIF, ONG, PCX, PNG, and XBM. Figure resolution for pixel-based images should be at least 1,200 dpi for line art (e.g., graphs, flow charts) or 500 dpi for photographs, micrographs, CT scans, and related images. Color images should use CMYK color mode.

Additional instructions for the electronic submission of artwork can be found on the Elsevier Author Support website at http://www.elsevier.com/framework_authors/Artwork/Artwork.pdf.

Authors must bear all costs associated with printed color figures and tables. The cost of the first color figure is $650.00, each additional figure is $100.00. If authors elect not to print figures in color, in most cases, figures will appear in black and white in the print issue of JCE, but will appear in color online.

If any table or figure has been published previously, a copy of the letter of permission from the copyright holder must accompany the manuscript. The original source of the table or figure should be acknowledged in full reference form in the reference section of the manuscript. The figure legend (or table notes) should conclude with: ‘‘Reprinted with permission’’ followed by the appropriate reference number. Authors are responsible for applying for permission for both print and electronic rights for all borrowed materials, and they are responsible for paying any fees related to the application of these permissions.

Review and Production Process
Manuscripts are examined by both Editors and two reviewers. Decisions of the Editors are final. All material accepted for publication is subject to copy-editing. Authors will receive page proofs of their article before publication, and should answer all queries and carefully check all editorial changes at this point. Authors are urged to check their proofs carefully before return, since late corrections cannot be guaranteed for inclusion in the scheduled issue. Authors are responsible for the specific content of their articles. Reprints may be purchased using the order form that is sent with the page proofs.

Neither the Editors nor the Publisher accept responsibility for the views and statements expressed by authors in their communications.