CONSORT 2025 · Randomized Controlled Trials

The CONSORT 2025 checklist, section by section.

CONSORT is the reporting standard for randomized controlled trials. Most journals require it. Most reviewers know it by heart. This is a complete walkthrough of what each section actually requires — and the specific items that decide whether your trial manuscript advances or stalls at the editor's desk.

The guideline

What CONSORT is.

CONSORT — the Consolidated Standards of Reporting Trials — is the international reporting guideline for randomized controlled trials. It exists because, for decades, published trial reports omitted the information readers needed to judge internal validity: how participants were randomized, who was blinded, how missing data were handled, what the primary outcome actually was before the trial began. CONSORT specifies the minimum a trial manuscript must contain so reviewers, clinicians, and meta-analysts can evaluate and replicate it.

The guideline is maintained by the CONSORT Group under the umbrella of the EQUATOR Network, the international initiative that develops and curates reporting guidelines. CONSORT 2010 was the version most authors trained on for fifteen years. CONSORT 2025 is the latest update — it preserves the six-section structure of the 2010 statement (Title and abstract, Introduction, Methods, Results, Discussion, Other information) and extends it with clearer guidance on harms reporting, trial design transparency, and open-science items such as protocol availability and data and code sharing.

CONSORT applies to any randomized trial. Specific extensions handle cluster, crossover, non-inferiority and equivalence, pragmatic, pilot and feasibility, and adaptive designs — but the core checklist is the same. If your study randomly allocated participants to comparison groups, this is the standard your manuscript will be judged against.

The checklist

CONSORT 2025, section by section.

The checklist is organized into the six manuscript sections every reviewer reads in order. These are the topics each section must cover — what is required, and why reviewers care.
01
Title and abstract
The title must identify the study as a randomized trial. The abstract must be structured (background, methods, results, conclusions) and must report the design, participants, interventions, primary outcome, results with effect estimates and uncertainty, harms, and trial registration number. Reviewers look here first — an abstract that hides the design or omits the primary outcome and its effect estimate is an immediate red flag.
02
Introduction — background and objectives
State the scientific rationale and the specific objectives, including pre-specified primary and secondary hypotheses. Reviewers check that the objectives stated here match the protocol, the registry record, and the primary outcome reported in Results. Misalignment across these three sources is one of the clearest signals of post-hoc outcome switching.
03
Methods — trial design
Describe the design (parallel, factorial, crossover, cluster), the allocation ratio, and any changes to methods after the trial began (with reasons). For non-inferiority and equivalence trials, the margin and its justification must be reported. This is where reviewers verify that the design described actually supports the conclusions later in the manuscript.
04
Methods — participants
Eligibility criteria for participants and settings, plus the locations where the data were collected, must be described in enough detail that another team could replicate enrollment. Vague age ranges, undefined disease states, or unstated recruitment settings make it impossible to assess generalizability.
05
Methods — interventions
Each intervention must be described with sufficient detail to allow replication — dose, route, duration, schedule, who delivered it, and what the comparator received. Drug names alone are not enough. For complex interventions (behavioral therapy, surgical procedures, devices), the level of detail required is higher, not lower.
06
Methods — outcomes
Completely defined pre-specified primary and secondary outcomes, including how and when they were assessed. Any changes to trial outcomes after the trial began, with reasons. This is the item most often violated — outcomes added after data are seen, primary outcomes demoted to secondary, or definitions tightened to capture the desired signal. Reviewers will compare what you report here to your registered protocol.
07
Methods — sample size
How sample size was determined: anticipated effect size, variance estimate, significance level, power, and the rationale for any interim analyses or stopping rules. "We enrolled 100 patients per arm" is not a sample size justification. Reviewers expect the full calculation with the values used and where the inputs came from.
08
Methods — randomization (sequence, allocation, implementation)
Three distinct items: the method used to generate the random allocation sequence (including any restriction such as blocking and block size); the mechanism used to implement the sequence (e.g., sequentially numbered opaque containers, central web-based allocation), describing whether the sequence was concealed until interventions were assigned; and who generated the sequence, who enrolled participants, and who assigned participants to interventions. Vague randomization ("randomized by computer") is a major issue.
09
Methods — blinding
If done, who was blinded after assignment to interventions (e.g., participants, care providers, those assessing outcomes) and how. If relevant, a description of the similarity of interventions. Open-label trials are not penalized — but they must be declared and justified, and the implications for outcomes susceptible to ascertainment bias must be acknowledged.
10
Methods — statistical methods
Statistical methods used to compare groups for primary and secondary outcomes, methods for additional analyses (subgroup, adjusted, sensitivity), and how missing data were handled. Pre-specification is critical — analyses described here but not pre-registered carry less weight, and analyses not described here but appearing in Results are an automatic flag.
11
Results — participant flow
A CONSORT flow diagram is effectively required: for each group, the numbers of participants randomly assigned, receiving intended treatment, completing the study protocol, and analyzed for the primary outcome, with reasons for losses and exclusions. Counts must reconcile. "450 randomized, 200 analyzed" with no explanation of the 250 missing is one of the most common — and most fixable — reasons for rejection.
12
Results — recruitment, baseline data, numbers analyzed
Dates defining the periods of recruitment and follow-up. A baseline characteristics table by group. The numbers analyzed for each outcome, with whether the analysis was by original assigned groups (intention-to-treat). Per-protocol or completers-only analyses presented as primary instead of ITT is a major issue and is flagged immediately.
13
Results — outcomes and estimation
For each primary and secondary outcome: results for each group, the estimated effect size, and its precision (such as 95% confidence interval). Binary outcomes require both absolute and relative effect sizes. Effect sizes and confidence intervals — not p-values alone — are what reviewers expect.
14
Results — ancillary analyses
Results of any other analyses performed, including subgroup analyses and adjusted analyses, distinguishing pre-specified from exploratory. Subgroup findings presented without explicit interaction tests, or framed as confirmatory when they were exploratory, are common overreaches.
15
Results — harms
All important harms or unintended effects in each group, with a clear severity and causality framework. CONSORT 2025 places greater weight on harms reporting — "the drug was well tolerated" without counts, grading, or comparison is no longer adequate.
16
Discussion — limitations, generalizability, interpretation
Trial limitations addressing sources of potential bias, imprecision, and (if relevant) multiplicity of analyses. The generalizability (external validity, applicability) of the findings. An interpretation consistent with results, balancing benefits and harms, and considering other relevant evidence. Discussions that overreach beyond what the data support — or fail to acknowledge limitations the reviewer can see — undermine the manuscript's credibility.
17
Other information — registration, protocol, funding
Registration number and registry name (e.g., ClinicalTrials.gov, ISRCTN); where the full trial protocol can be accessed; sources of funding and other support (such as drug supply), role of funders. CONSORT 2025 expands this with open-science expectations around protocol, data, and code availability. Unregistered trials and trials registered after enrollment are flagged.
The contrast

Adequate vs. inadequate reporting.

Three of the items most consistently missed in submitted RCT manuscripts. Each shows the version that fails review next to the version that passes — with the reasoning a reviewer would use.
Randomization and allocation concealment
Inadequate
"Participants were randomized by computer to treatment or control."
Adequate
"A computer-generated random sequence (random permuted blocks of size 4 and 6, stratified by site and baseline severity) was prepared by an off-site statistician. Allocation was concealed using a central web-based system accessed by enrolling clinicians after participant eligibility was confirmed; clinicians could not predict assignments."
Why it mattersThe inadequate version names the method (computer) but leaves selection bias unassessable — was the sequence concealed? Could enrollers see upcoming allocations? The adequate version separates sequence generation from allocation concealment from implementation, which is exactly what CONSORT requires.
Primary outcome and changes to outcomes
Inadequate
"The primary outcome was clinical improvement at 12 weeks."
Adequate
"The primary outcome was the proportion of participants achieving a ≥50% reduction in [scale] score from baseline to week 12, assessed by a blinded outcome assessor using the validated [instrument]. This outcome and analysis were pre-specified in the protocol registered at ClinicalTrials.gov (NCT0XXXXXXX) before enrollment began. No changes were made to the primary outcome after trial initiation."
Why it matters"Clinical improvement" is undefined — by whom, by what threshold, on what instrument, at what time point. The adequate version operationalizes the outcome, names the assessor, references the registry, and explicitly confirms no post-hoc changes. Reviewers will check the registry; the absence of this statement does not protect the manuscript.
Participant flow and intention-to-treat
Inadequate
"Of 450 randomized participants, 340 (76%) completed the trial and were included in the analysis."
Adequate
"Of 450 participants randomized (225 per arm), all 450 were included in the intention-to-treat analysis of the primary outcome in their originally assigned groups. Loss to follow-up was 24 (5.3%) in the treatment arm and 26 (5.8%) in the control arm; reasons are reported in the CONSORT flow diagram (Figure 1). Missing primary-outcome data (1.8% overall) were handled by multiple imputation under a missing-at-random assumption (20 imputations, MICE, Rubin's rules pooling); a per-protocol analysis is reported as a secondary sensitivity analysis."
Why it mattersThe inadequate version presents per-protocol as primary, hides the 110 missing participants, and gives no missing-data method. The adequate version names ITT, accounts for every participant, locates the flow diagram, and pre-specifies the missing-data handling. This is the difference between "requires major revision" and "acceptable."
The check

How PeerReviewAI evaluates CONSORT compliance.

CONSORT 2025 compliance is checked on every RCT manuscript submitted to AI Peer Review — including the lowest tier. No add-on required.
01
Auto-detected as an RCT
Upload your manuscript and an RCT is identified automatically. CONSORT 2025 is used as the reporting checklist — you do not have to choose it.
02
Item-by-item qualitative assessment
Every CONSORT item is evaluated against your manuscript text. The output is a qualitative judgment per item: adequate, incomplete, or missing — never a single composite score that hides which items failed.
03
Specific, locatable feedback
For every item that is incomplete or missing, you get a specific note: what the item requires, what your manuscript currently says, and what is missing. Findings reference manuscript sections rather than item numbers in isolation.
04
Included in every tier
CONSORT compliance checking is part of Essentials ($2.99), Peer Review ($29), and Author Review ($79). It is not an add-on. The deeper tiers provide more extensive Major/Minor Issue analysis and (for Author Review) a compliance audit against your target journal's author guidelines.
Related guidelines

If your study is not an RCT.

CONSORT 2025 · checked on every RCT

Check your trial against CONSORT 2025.

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