Strata Academy

CONSORT explained – reporting randomised trials transparently

25-item checklist, flow diagram, reporting vs risk of bias, and pairing with ROB 2

1. What is CONSORT?

CONSORT (Consolidated Standards of Reporting Trials) is an evidence-based minimum set of recommendations for reporting randomised controlled trials. It helps readers assess whether a trial was conducted and reported with enough transparency to judge validity.

CONSORT is a reporting guideline – not a risk-of-bias tool. Complete reporting makes ROB 2 easier; incomplete reporting forces 'unclear' judgements in bias domains.

2. CONSORT vs ROB 2

CONSORT asks: did authors report allocation, blinding, outcomes, and harms clearly? ROB 2 asks: given what was done, how biased is the effect estimate?

A trial can have good CONSORT reporting but high ROB 2 risk (e.g. high attrition). Conversely, poor reporting obscures bias assessment even if conduct was sound.

• CONSORT → transparency and completeness of the write-up
• ROB 2 → validity of the causal inference
• Use both for RCT appraisal

3. CONSORT flow diagram

The flow diagram tracks participants from enrolment through allocation, follow-up, and analysis. Compare numbers randomised vs analysed – discrepancies signal attrition or exclusion bias.

• Assessed for eligibility (n)
• Randomised (n)
• Allocated to each group, received intervention, analysed
• Losses and exclusions with reasons

4. High-yield checklist items

For student appraisal, these items most often drive interpretability.

• Trial design description (parallel, factorial, crossover)
• Eligibility criteria and settings
• Interventions described so they can be replicated
• Primary outcome defined a priori with time point
• Sample size calculation and interim analyses
• Randomisation method and allocation concealment
• Blinding – who was blinded to what
• Statistical methods matched to design
• Harms and adverse events reported
• Trial registration number and protocol access

5. CONSORT extensions

Non-inferiority, equivalence, cluster, pragmatic, and patient-reported outcome trials have CONSORT extensions. Check EQUATOR for the matching extension when the design is specialised.

6. Using CONSORT in journal club

Complete a abbreviated CONSORT table: item present / absent / unclear. Pair with ROB 2 domain judgements. Flag items that block bias assessment (e.g. no allocation concealment description).

7. StrataResearch and CONSORT

RCT manuscripts receive CONSORT-aligned reporting feedback alongside ROB 2 domain scoring – reporting gaps are separated from bias judgements.

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