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Massachusetts Medical Society

Prepare your manuscript for New England Journal of Medicine.

Review the checklist, choose your article type, and turn your draft into a cleaner submission package.

Checked 2026-08-21
Check readiness freePrepare this manuscript

Article types

Letter
Editorial
Review
Commentary
Clinical Trial
Protocol
Lectio
Original Article

Readiness requirements

Review the key details below, or download the complete checklist with every stored source-backed requirement.

Abstract length

  • Provide an author-written abstract of no more than 250 words.
  • In the Abstract and Results sections of the manuscript, authors should report analyses that address missing data using appropriate methods and assumptions about missing data, such as missing at random. d.
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  • Clinical Trial: Title Page Create a title page that includes: Manuscript title Each author’s name, highest degree, and affiliation/institution Contact information for one corresponding author Abstract Provide an abstract of not more than 250 words with four labeled paragraphs containing the following: Background: Problem being addressed in the study Methods: How the study was performed Results: Salient results Conclusions: What the authors conclude from study results Trial registration number Identifying Data At appropriate places in the manuscript, please provide the following items: If applicable, a statement that the research protocol was approved by relevant institutional review boards or ethics committees and that all human participants gave written informed consent Identities of those who analyzed the data For clinical trials, registration number and registry name (see: N Engl J Med 2004;351:1250-1) For studies containing microarrays, accession numbers and repository name References References must be double-spaced and numbered consecutively as they are cited.

Reference style

  • Articlo formats your supplied references to the journal's stored style and checks that citations match the reference list; source validity is not verified.
  • Reference citations in the Appendix and the corresponding list of references should be self-contained with respect to the Appendix.
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  • There must be an informative reference citation for the scale.
  • References first cited in a table or figure legend should be numbered so they will be in sequence with references cited in the text at the point where the table or figure is first mentioned.
  • Supplementary Appendix A manuscript’s Supplementary Appendix should be paginated, with a table of contents, followed by a list of investigators (if there is one), text (such as methods), figures, tables, and then references.

Figure and table rules

  • Keep every figure and table numbered, captioned, and cited in the manuscript.
  • Group tables at the end of the manuscript.
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  • P values should not be included in the traditional Table 1 of a randomized trial manuscript showing the distribution of baseline variables by treatment group.
  • Tables in the Supplementary Appendix should be labeled Table S1, Table S2, etc. Each table should be accompanied by a title and, if necessary, footnotes.
  • The manuscript should report the number of participants with missing data for baseline variables (e.g., in Table 1) and for all variables used in analyses, including response and predictor variables. c.
  • Figures and tables should use conventional units, with conversion factors given in legends or footnotes.
  • Tables All tables should be included at the end of the manuscript text file.
  • To avoid copyright concerns, we strongly recommend that you do not submit finished illustrations.
  • Each figure should include a title and a legend, which should appear on the same page as the figure itself.
  • Please provide a simple sketch, diagram, or PowerPoint slide, along with a clear figure legend, and/or a brief written description of the figure’s educational purpose or key learning objective.

Competing interests

  • Letter: Prepare Materials for Submission Cover Letter Though cover letters are not required, the NEJM Online Submission system contains a text field through which important information that is not in the metadata, such as a meeting presentation date or a major conflict of interest not in the manuscript, should be communicated with initial manuscript submissions.

Ethics statement

  • Add or confirm the author-written Ethics statement; Articlo flags it if author input is still needed.

Cover letter

  • Submit to NEJM Click the button below to log in to the NEJM online submission system (ScholarOne Manuscripts) to submit a new manuscript.

Supplementary files

  • Include every cited supplementary file and use matching labels in the manuscript.
  • Details on sensitivity analyses that assess the impact of alternative assumptions about missing data should be provided in the supplementary appendix. f.
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  • Although all this information may not be published with the manuscript, it should be provided in either the manuscript or a supplementary appendix at the time of submission.

Title page and author information

  • Provide the author, affiliation, and correspondence details for the separate title page; Articlo creates the editable companion file.

Reporting guidelines

  • Authors reporting sensitivity analyses should consult Morris et al. (BMC Medical Research Methodology 2014;14:11) for guidance and examples.
  • In general, P values larger than 0.01 should be reported to two decimal places, and those between 0.01 and 0.001 to three decimal places; P values smaller than 0.001 should be reported as P h.
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  • The SAP should contain enough detail to enable someone else to replicate the analysis in a similar data set.
  • Documents should be dated, and changes in the study plans and accompanying rationale should be described.
  • Clinical Trial: For clinical trials, formal protocol amendments and corresponding changes to the SAP will typically be available and should be included with the manuscript submission. b.
  • Significance tests should be accompanied by effect estimates with standard errors or confidence intervals. e.
  • Confidence intervals for ratio quantities, such as relative risks, odds ratios, and hazard ratios, should be computed in the log-scale for inclusion in forest plots. f.
  • Unless one-sided tests are required by the study design, such as noninferiority trials, all reported P values should be two-sided. g.
  • For example, measures of association, such as odds ratios, should ordinarily be reported to two decimal places.
  • P values adjusted for multiplicity should be reported when appropriate and labeled as such in the manuscript.
  • In hierarchical testing procedures, P values should be reported only until the last comparison for which the P value was significant.
  • Thus, P values for the first nonsignificant comparison and for all comparisons thereafter should not be reported. c.
  • Because these assumptions cannot be tested with data, they should be accompanied by contextual justification. e.
  • When reporting HR estimates, the manuscript should address the appropriateness of the PH assumption and provide corroborating evidence.
  • If the PH assumption appears to be inconsistent with the data, HR estimates should not be reported and alternative metrics should be used to report comparisons.
  • HRs estimated with a Cox PH estimate may also be biased and should be replaced by measures of association that account for dependent competing risks.
  • When a Bayesian approach to the design and analysis of a study has been chosen, the approach should be applied consistently.
  • The design should be based on Bayesian considerations, and the analysis should be consistent with the design. b.
  • When a Bayesian analysis is planned for a study, the protocol and SAP should describe the key elements of the approach.
  • However, authors should note imbalances in potential confounders that could be due to chance or inconsistencies in randomization. c.
  • In any case, an SAP document must be submitted, even if it was not prepared during the conduct of the study.
  • The SAP should be dated and should make clear whether it was written before or after preliminary data analyses. d.
  • The Appendix must be submitted in two formats: PDF and MS Word (or another editable text format).
  • They are required for all interventional trials.
  • Clinical Trial: For confirmatory analyses, such as those typically reported for end points in clinical trials, the SAP should prespecify a plan to control overall type I error (family-wise error rate).
  • When some censoring may be due to dependent competing events, Kaplan–Meier estimates of event-time distributions may be biased and should be replaced by appropriate estimates of cumulative incidence.
  • Thus, if these analyses are not covered in the prespecified plan for multiplicity adjustment, the forest plots should not include P values for treatment by subgroup interactions. d.
  • In assessing robustness of findings about the primary end point, authors should distinguish between sensitivity analyses and other types of analyses (such as analyses of particular subsets).
  • Studies reporting the association of a treatment or exposure with an outcome should show the distribution of potential confounders and other variables, stratified by exposure or intervention group.
  • When the analysis depends on the confounders being balanced by exposure group, standardized mean differences between groups, calculated after matching, weighting, or other adjustment technique, should be reported. g.
  • Key Journal Style Elements Units of Measurement Authors should express all measurements in conventional units, with Système International (SI) units given in parentheses throughout the text.
  • Drug Names Generic names should be used.
  • Authors must clearly describe and identify all modifications, digital adjustments, and electronic enhancements made to submitted images, including changes to brightness, contrast, color balance, cropping, compositing, or annotation.
  • For data visualizations (e.g., bar graphs, line graphs, scatter plots, dot plots, survival curves, box-and-whisker plots, forest plots, flow diagrams, timelines, and maps), we request that you submit editable vector files (e.g., ai, eps, svg).
  • Unless missingness is rare, a complete case analysis is subject to potential bias and is generally not acceptable as the primary analysis.
  • When safety outcomes do not constitute primary end points in a study, no adjustment for multiplicity is necessary for their analysis.
  • Sensitivity analyses may be necessary to assess the impact of systematic or informative missingness (for example, when the missing-at-random assumption may not be viable).

Statistical reporting

  • A protocol document (or equivalent) and a statistical analysis plan (SAP) should be submitted with each manuscript.
  • Protocol: Protocol and statistical analysis plan documents should not be redacted except for names and contact information of individuals who may have signed the documents.
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  • The Methods section of the manuscript should contain a brief description of the methods for primary, secondary, and exploratory analyses, as well as a brief description of sample size considerations for the study, including statistical power computations when applicable.
  • The Methods section of the manuscript should include a description of the approach used to address missing data, including a statement of assumptions being made about the missing data or the missing data mechanism.

Preprints and prior publication

  • Authors should notify NEJM of any preprint related to a manuscript submission.

Artificial intelligence disclosure

  • Authors must also disclose whether any AI-assisted technologies were used at any stage of image processing (see our Editorial Policies).
  • Generative AI tools may not be used to create, alter, add, remove, or fabricate visual content within scientific or medical images.

Manuscript structure

  • More principled methods of analyzing a trial subject to nonadherence should be used, for example as discussed in Hernán and Robins (N Engl J Med 2017;377: 1391–8). f.
  • When no method to adjust for multiplicity of inferences was prespecified in the protocol or SAP, reporting of secondary and exploratory end points should be limited to point estimates of effects with 95% confidence intervals.
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  • Results should be presented with no more precision than is of scientific value and is meaningful, given the available sample size.
  • Results derived from models should be limited to the appropriate number of significant digits.
  • Protocol: Analyses that do not conform to the protocol should be justified in the Methods section of the manuscript.
  • The Methods section of observational studies manuscripts should describe how these and other relevant issues were addressed in study design and analysis. b.
  • As noted in the section on general requirements, a protocol document and an SAP document must be submitted with the manuscript.
  • The choice of method should be justified and be accompanied by diagnostics. f.
  • For exploratory analyses, such as genomewide association studies, investigators may use methods for controlling false discovery rate; the methods should be prespecified in the protocol or SAP. d.
  • In such cases, the Methods section should state that the widths of the intervals have not been adjusted for multiplicity and that the intervals may not be used in place of hypothesis testing.
  • The results of a Bayesian analysis should be accompanied by an adequate exploration of the sensitivity of the reported inferences to assumptions about the prior distributions. d.
  • Clinical Trial: The analysis of the primary outcome in manuscripts reporting results of clinical trials should match the analyses prespecified in the final protocol and SAP, except in unusual circumstances.
  • If authors plan to rely on odds ratios in the analysis, a justification should be provided in the Methods section addressing the concerns that odds ratios may overestimate the relative risks and may be misinterpreted. h.
  • The SAP should include the aims of the study, identify primary and secondary end points, and describe the eligibility criteria for the selection of cases and method of sampling from the data, with a diagram as appropriate.
  • The SAP should also provide a detailed description of the association or causal effect to be estimated and the rationale for this choice, and describe the prespecified methods of analysis to draw inference about treatment or exposure effect or association and plans to control for multiplicity of inferences, as discussed earlier in these guidelines.
  • In studies in which estimating a causal effect is the goal, the analysis should use methods specifically designed for causal inference and should be accompanied by a description of the assumptions required to support a causal interpretation.
  • Authors are encouraged to conduct an analysis that quantifies potential sensitivity to bias from unmeasured confounding; in the manuscript, authors must provide a discussion of potential biases induced by unmeasured confounders. h.
  • To enhance the reproducibility of study results, the Journal emphasizes the need to account for the multiplicity of hypothesis testing in the analysis and to control the probability of error.

Language and text style

  • The interpretation of these confidence intervals should avoid the language of definitive conclusions used to report statistically significant findings as assessed by formal hypothesis testing.
  • Causal language (e.g., exposure X leads to outcome Y, or changes in exposure X produce changes in outcome Y) should not be used in observational studies where only associations can be estimated. e.
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  • Abbreviations Except for units of measurement, abbreviations are strongly discouraged; the first time an abbreviation appears, it should be preceded by the words for which it stands.

Study reporting guidelines

  • Authors should provide a flow diagram in CONSORT format.
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What your package checks

Abstract: 250 words
Title page: separate file
Declarations: Ethics
Format: double spacing

Source transparency

This preparation guide uses published journal-specific author requirements. Journal instructions can change, so authors should complete a final review before submission.

Open official guideline source
New England Journal of Medicine manuscript requirements | Articlo