Cohort overview — Prospective observational cohort

Question

Define the population, longitudinal outcome and intended use of the findings.

Protocol and permissions

Specify the protocol, participant permissions, ethics and planned public protocol record before recruitment.

Recruit and enroll

Use a defined recruitment frame and enrollment milestone; preserve reasons for nonparticipation.

Assess baseline

Measure baseline variables before the relevant exposure or risk period wherever the question requires it.

Follow participants

Collect scheduled outcomes and updated exposures; track missed visits, withdrawal and competing events.

Finalize data

Resolve queries, document deviations and version the analysis dataset and derivations.

Analyze

Use methods compatible with repeated observations, confounding where relevant, and missing or censored follow-up.

Report

Report retention, measurement timing, estimates and uncertainty without equating observed associations with randomized effects.

Cohort 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 rationale and dated protocol, retaining amendments. A study registry records study details; a disease registry contains health data. The HMA–EMA Catalogue of RWD studies is one option for relevant studies. Check eligibility and applicable requirements, and record an identifier and timing if registered. Registration does not imply randomization.