To trace a claim in a review back to its original primary study, read the review's citation for that claim, open the cited study, and confirm that it reports the claim directly; if the cited study is itself a review, repeat the process with its citation until you reach the primary study. This follows the ICMJE recommendation to verify references against original sources and to cite direct sources where possible.
- Locate the citation. Find the reference number or author-year in the review that supports the specific claim. Check the reference list for the full citation details.
- Open the cited study. Retrieve the full text of the cited work. If the citation points to another review, note its citation for the same claim and return to step 1.
- Confirm direct reporting. In the primary study, check that the results or discussion explicitly state the claim. If the primary study does not report the claim directly, the review's citation may be indirect or inaccurate; look for another primary source or revise the claim.
- Document the chain. Record each step from review to primary study, including the citation details, so you can retrace the path later.
For finding full texts or checking citation details, Google Scholar supports title searches with quotation marks and cited-by links, and the Cochrane Handbook describes searching reference lists and other sources to locate studies. These tools help you locate the primary study, but the confirmation step remains reading the primary study itself.