The general approach to IPD meta-analysis is the same as for any other systematic review, and the methods used should differ substantially only in the data collection, checking and analysis stages. Just as for any Cochrane review, a detailed protocol should be prepared, setting out the objective for the review, the specific questions to be addressed, study inclusion and exclusion criteria, the reasons why IPD are sought, the methods to be used and the analyses that are planned. Similarly, the methods used to identify and screen studies for eligibility should be the same irrespective of whether IPD will be sought, although the close involvement of the original researchers in the project might make it easier to find other studies done by them or known to them. The project should culminate in the preparation and dissemination of a structured report. An IPD review might also include a meeting at which results are presented and discussed with the collaborating researchers.