EditverseWriting the Research Strategy for the NIH simplified review framework
The three NIH review factors, the questions reviewers answer under each, where to put the evidence in Significance, Innovation and Approach, and what is no longer scored.
Key points
- For most NIH research project grants with due dates on or after 25 January 2025, the five review criteria are grouped into three factors: Importance of the Research, Rigor and Feasibility, and Expertise and Resources.
- Factors 1 and 2 each receive a criterion score from 1 to 9. Factor 3 is judged appropriate or as having gaps, with no numerical score. All three inform the overall impact score.
- The Research Strategy keeps its three headings, Significance, Innovation and Approach, and its page limit. NIH describes the change as the same research strategy reviewed in a new way.
- Inclusion plans and clinical trial timelines are now assessed inside Factor 2. Resource sharing plans, select agents and foreign organisation questions are reviewed by NIH staff, not by peer reviewers.
What changed and for which applications
NIH announced the simplified review framework in notice NOT-OD-24-010, released on 19 October 2023, and applies it to research project grant applications with due dates on or after 25 January 2025.2 The framework covers the activity codes R01, R03, R15, R16, R21, R33, R34, R36, R61, RC1, RC2, RC4, RF1, RL1, RL2, U01, U34, U3R, UA5, UC1, UC2, UC4, UF1, UG3, UH2, UH3 and UH5, including phased awards such as R21/R33 and UG3/UH3.1 Activity codes outside this list, such as fellowship and career development awards, are not covered by the framework.
NIH gives two reasons for the change: the complexity of the review process, and the potential for an applicant's or institution's general reputation to affect review outcomes.1 The five regulatory criteria remain. They are regrouped so that reviewers concentrate on three questions: how important is the proposed research, how rigorous and feasible are the methods, and do the investigators and institution have the expertise and resources to carry it out.
| Factor | Former criteria | How it is assessed | Main evidence in the application |
|---|---|---|---|
| 1. Importance of the Research | Significance; Innovation | Criterion score, 1 to 9 | Specific Aims; Significance and Innovation sections |
| 2. Rigor and Feasibility | Approach, now also covering inclusion and clinical trial study timeline | Criterion score, 1 to 9 | Approach section; human subjects and clinical trials information |
| 3. Expertise and Resources | Investigators; Environment | Appropriate, or gaps identified with an explanation; no individual score | Biographical sketches; facilities and resources; letters; leadership plan |
NIH states that an application does not need to be strong in all categories to be judged likely to have major scientific impact.1
What reviewers are asked under each factor
The table paraphrases the review criteria published on the NIH framework page and places each beside the part of the Research Strategy where the answer should be found.1 The section headings and their order are fixed by the application instructions, and the funding opportunity overrides the general guide where the two differ.35
| Factor | What the reviewer evaluates | Where to answer it | What to write there |
|---|---|---|---|
| 1 | Importance of the research in the context of current challenges and opportunities: does it address an important gap, solve a critical problem or create a valuable conceptual or technical advance? | Significance, opening | The problem, its scale, and the specific gap, in the first half page. |
| 1 | The rationale for the study and the rigour of the scientific background, such as prior literature and preliminary data, and whether that background justifies the study. | Significance, middle | A critical account of the key prior studies: design, size, limitations, and what remains unresolved. The instructions ask for strengths and weaknesses in the rigour of prior research. |
| 1 | The extent to which innovation influences the importance of the work; whether novel concepts, methods or technologies are applied, or existing ones used in novel ways. A project without novel concepts or approaches may still be of critical importance. | Innovation | What is new and why that matters for answering the question. If the value lies in a definitive test and not in novelty, say so. |
| 2 | Rigour: potential for unbiased, reproducible data; rigour of design and appropriate controls; whether sample size is sufficient and well justified; quality of plans for analysis, interpretation and reporting; plans for relevant biological variables such as sex or age. | Approach, design and analysis subsections for each aim | Design, randomisation or control strategy, blinding, outcome definitions, sample size with assumptions, analysis plan, handling of missing data, and how sex and age enter design and analysis. |
| 2 | For human or animal studies: rigour of the intervention; whether outcome variables are justified; generalisability; whether the sample is appropriate and sufficiently diverse for the question. | Approach, population and outcomes | Why these outcomes, why this population, and to whom results will apply. |
| 2 | For human subjects research: adequacy of inclusion plans as appropriate to the scientific goals. | Approach, with detail in the human subjects and clinical trials form | A short scientific justification of who is included, with reference to the condition's distribution; the tables go in the form. |
| 2 | Feasibility: whether the approach is sound and achievable, with plans to address problems or new challenges; where feasibility is less certain, whether the uncertainty is balanced by the potential for major advances. | Approach, preliminary studies and "potential problems and alternatives" for each aim | Preliminary data that show each key step can be done; named risks with a specific alternative for each. |
| 2 | For human subjects research: adequacy and feasibility of the recruitment and retention plan and likelihood of reaching proposed enrolment. For clinical trials: whether the study timeline and milestones are feasible. | Approach, recruitment and timeline | Screening-to-enrolment estimates from real site data; a timeline with milestones that matches the budget period. |
| 3 | Whether investigators have the background, training and expertise, as appropriate for career stage, to conduct the work; for multiple principal investigators, the quality of the leadership plan. Whether institutional resources are appropriate. | Outside the Research Strategy | In the strategy, one sentence per aim on who does what is enough. The detail belongs in the biosketches, resources page and leadership plan. |
Writing Significance for Factor 1
The application instructions ask the Significance section to explain the importance of the problem or critical barrier, to describe the strengths and weaknesses in the rigour of the prior research that supports the project, and to explain how the project will improve scientific knowledge, technical capability or clinical practice.3 The reviewer's Factor 1 questions follow the same order. A section built in three blocks, with the instruction's own terms as run-in headings, makes the match visible.
Illustrative example: the "rigour of prior research" paragraph
The studies and figures in this paragraph are invented to show the form.
Rigour of prior research. Support for early mobilisation after hip fracture surgery rests on three bodies of evidence. Two single-centre randomised trials (n=96 and n=140) reported faster recovery of walking, but neither blinded outcome assessors and both excluded patients with cognitive impairment, who make up about 40% of this population. Four cohort studies found lower 30-day mortality with mobilisation on the first postoperative day; all were retrospective and could not separate the effect of mobilisation from the fitness that allowed it. A 2024 meta-analysis rated the certainty of evidence as low for function and very low for mortality. Strengths of this literature are consistent direction of effect and a plausible mechanism. Its weaknesses are small samples, unblinded assessment, confounding by indication and exclusion of the patients at highest risk. The proposed trial addresses each: it is multicentre, uses blinded assessors, randomises the timing of mobilisation, and includes patients with cognitive impairment through consent procedures described in the human subjects section.
The paragraph does three things a reviewer can score. It shows the applicant knows the evidence base, it names weaknesses without dismissing the field, and it ties each weakness to a design feature of the proposal. That last link is repeated in the Approach, where the instructions ask how weaknesses in prior research will be addressed.3
Writing Innovation for Factor 1
Innovation no longer has its own score, and the criterion wording now says that a project that does not apply novel concepts or approaches may still be of critical importance.1 This changes the job of the section. It no longer needs to claim novelty for its own sake. It needs to show how what is new, whether a concept, a method, a population or a use of existing tools, makes the research more important. Three or four specific points, each ending in the consequence for the question, serve better than a general statement. A confirmatory trial can state plainly that its contribution is a definitive answer, and use the section to describe any methodological refinement that makes that answer more reliable.
Writing Approach for Factor 2
Factor 2 carries the largest number of reviewer questions, and the Approach section usually takes most of the page limit. A consistent structure for each aim lets reviewers find the answers.
Rationale and preliminary data
Two or three sentences linking the aim to the hypothesis, then the data that show feasibility. The instructions note that preliminary data are not required for some mechanisms, such as R03 and R15 applications; for an R01 they help establish the likelihood of success.3
Design
Study design, setting, participants, intervention or exposure, comparator, outcomes with timing. State controls and any blinding.
Sample size and analysis
The primary comparison, assumptions with their source, power, allowance for attrition, the model, and handling of missing data. For cluster or group-randomised designs the instructions ask applicants to show that analysis and sample size methods fit the assignment.3
Biological variables
How sex and other relevant variables such as age are built into design, analysis and reporting. A single-sex study needs strong justification.3
Inclusion, recruitment and retention
Who will be enrolled and why that is right for the science; expected screening and enrolment rates; retention measures. Tables and detailed plans go in the human subjects and clinical trials form, and the instructions ask applicants not to duplicate content between the two.3
Potential problems and alternatives
Named risks, each with a decision rule and an alternative. The instructions ask for potential problems, alternative strategies and benchmarks for success.3
Timeline and milestones
For clinical trials, reviewers assess whether timeline and milestones are feasible. A one-row-per-aim chart by project year is sufficient.
| Section | Pages | Content |
|---|---|---|
| Significance | 1.5 to 2 | Problem and gap; rigour of prior research; expected contribution |
| Innovation | 0.5 | Three or four specific points |
| Approach: overview and preliminary studies | 1.5 to 2 | Overall design figure; team roles in a sentence; data supporting feasibility |
| Approach: Aims 1 to 3 | 6 to 7 | About two pages per aim in the structure above |
| Approach: rigour summary, timeline | 0.5 to 1 | Cross-aim statement on bias control and reproducibility; milestone chart |
The plan is a starting allocation, not an NIH requirement. The 12-page limit applies to the whole Research Strategy attachment for R01 applications and 6 pages for R03 and R21, unless the funding opportunity states otherwise.4 For renewals, the progress report is part of the Research Strategy and counts toward the limit.3
What moved, and what is no longer scored
| Item | Before 25 January 2025 | Under the simplified framework |
|---|---|---|
| Investigators; Environment | Each scored | Combined as Factor 3; appropriate or gaps identified; no individual score; considered in overall impact |
| Significance; Innovation | Each scored | One score for Factor 1 |
| Approach | Scored | Score for Factor 2, with inclusion and clinical trial timeline folded in |
| Inclusion of women, minorities and individuals across the lifespan; study timeline for clinical trials | Additional review criteria | Evaluated within Factor 2 |
| Human subjects protections; vertebrate animals; biohazards; resubmission, renewal, revision | Additional review criteria | Still additional review criteria; can affect the overall impact score |
| Applications from foreign organisations; select agent research; resource sharing plans | Additional review considerations for peer reviewers | Reviewed administratively by NIH staff before funding |
| Authentication of key biological and chemical resources; budget and period of support | Additional review considerations | Still considered by reviewers; no effect on overall impact score |
Two consequences follow for applicants. First, the investigator and environment pages should be written to the work proposed: reviewers are asked whether expertise and resources are sufficient for this project, and a gap they identify must be explained in the critique.12 Name the expertise each aim needs and show who supplies it. Second, inclusion and recruitment are now part of the scientific score. NIH states that the move is meant to emphasise their importance to scientific merit and not as matters of policy compliance.1 A thin enrolment plan is now a weakness under Factor 2.
Editverse Medical audits Research Strategy drafts against the review factors and drafts sections with the applicant; the entry points are on the research grant proposal page. Power calculations and the analysis subsection can be prepared separately under sample size, power and study design. See grant writing for the full range. The scientific ideas, the application and its submission remain the applicant's.
Frequently asked questions
Do I need to restructure my Research Strategy into three factors?
No. The instructions still require the headings Significance, Innovation and Approach in that order. The factors are how reviewers organise their assessment, not how the applicant organises the attachment.
Is Innovation still important if it has no separate score?
It is assessed with Significance under Factor 1. Reviewers evaluate how far innovation adds to the importance of the research, and the criteria state that a project without novel concepts or approaches may still be of critical importance.
How is the overall impact score related to the factor scores?
Reviewers consider all three factors, and the additional review criteria where they apply, in giving an overall impact score that reflects the likelihood of a sustained, powerful influence on the field. The overall score is the reviewer's judgement and is not calculated from the factor scores.
Does the framework apply to K and F applications?
The simplified framework is defined for the listed research project grant activity codes. Fellowship and career development codes are not in that list, and they have their own page limits; check the review criteria in the specific funding opportunity.
References
- National Institutes of Health. Simplified Peer Review Framework. Page last updated 28 April 2026. NIH page
- National Institutes of Health. NOT-OD-24-010: Simplified Review Framework for NIH Research Project Grant Applications. Released 19 October 2023. NIH Guide notice
- National Institutes of Health. SF424 (R&R) Application Guide, Forms Version I. G.400 PHS 398 Research Plan Form: Research Strategy. NIH instructions
- National Institutes of Health. Page Limits. Page last updated 30 September 2026. NIH page
- National Institutes of Health. How to Apply: Application Guide. SF424 (R&R) Forms Version I, for due dates on or after 25 January 2025. NIH page