- Published
- Updated
One device study may produce initial results, subgroup papers and long-term follow-up reports. Separate publications do not necessarily represent independent participant groups. Mapping reports to a study family preserves both their additional information and the risk of counting the same data repeatedly.
Scope of the decision
A study identifier may not be stated clearly in every paper. Examine sites, recruitment periods, sample sizes, device models and investigators together. Similar authorship alone does not prove a shared study. Explain uncertain relationships and their analytical limits rather than merging reports automatically.
Worked review
For example, an early paper reports one hundred participants and a later paper describes two-year follow-up of the same group. The team does not combine them as two hundred independent participants. It records each report’s outcome and follow-up contribution and shows where the shared cohort is represented only once.
Practical checks
- Match publications using study identifiers and participant periods where available.
- Separate additional follow-up or subgroup information from a new independent sample.
- Check that combined analyses do not count the same participant repeatedly.
Acceptance and limits
Acceptance requires clarity about each report’s unique contribution and shared data. Removing every later publication merely to prevent duplication can also lose information. Selection of the most suitable report or joint use of reports should follow the analytical question and data coverage.
Frequently asked questions
- Do the same authors establish the same study?
- No. Consider site, period, sample and study information together.
- Is a follow-up paper unnecessary?
- No. It may add a different time horizon or outcome without increasing independent participant numbers.