Comparative intervention overview — Nonrandomized comparative interventional study

Question

State the comparative intervention question and why random allocation is not used.

Protocol and approvals

Document the assignment rule, comparator, confounding plan, safety and required approvals.

Register

Because investigators assign an intervention, assess prospective clinical-trial registration and record the actual registry and identifier before enrollment.

Recruit

Apply comparable eligibility and consent procedures across intervention groups.

Assign intervention by stated rule

Implement the stated nonrandom rule and retain the factors, sites and dates that determine assignment.

Follow

Use comparable follow-up, outcome measurement and safety monitoring across groups.

Address baseline differences

Select baseline adjustment variables using their temporal and causal roles; assess overlap and selection.

Analyze

Estimate the target contrast with compatible adjustment and uncertainty; assess residual confounding and time trends.

Report

Report assignment, baseline differences, attrition and limitations; use reporting guidance appropriate to the intervention.

Comparative intervention overview

End flow

Protocol and decision register

Record the protocol, approvals and registration where applicable. Preserve planned decisions and amendments separately from results.

Protocol and rationale evidence

Attach the dated protocol, approvals and amendments. A clinical trial registry publicly records the trial plan, such as ClinicalTrials.gov or an eligible WHO primary registry such as ISRCTN. Record the registry name, identifier and registration date before first enrollment. WHO ICTRP is a search platform, not itself a registry. Registration does not imply randomization.