Single-arm study overview — Single-arm interventional study

Question

Define the outcome or decision to estimate and justify a single-arm design.

Protocol and approvals

Prespecify eligibility, intervention, benchmarks, safety, stopping and analysis; obtain required approvals.

Register

Register prospectively in a public trial registry and record the registry name, identifier and date.

Recruit

Apply eligibility and consent procedures and distinguish enrolled from treated participants.

Intervene

Record actual intervention receipt, adherence, modifications and reasons for discontinuation.

Assess outcomes and safety

Collect planned outcomes and harms over defined windows, including relevant follow-up after stopping treatment.

Analyze against objective

Estimate the prespecified quantity; evaluate benchmark comparability, missing outcomes and uncertainty.

Report

Report all relevant denominators and limitations of inference without a randomized concurrent comparator.

Single-arm study 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.