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  1. Updates vs. amendments: a review is considered updated and receives a new citation in Cochrane Database of Systematic Reviews (CDSR) when a new search is conducted and the results of the search are fully incorporated. If a scoping search is conducted to determine if an update is required, then the date of this search will not change the 'Date of search' in the review or lead to a new citation version being created. This should be published as an amendment if necessary; see Assigning ‘What’s New’ events to Cochrane Reviews.
  2. If top-up searches are performed and the results incorporated then that top-up search date becomes the date of the full search (i.e. the date that appears in the ‘Date of Search’ field).
  3. If top-up searches are performed and the results are NOT fully incorporated then:  
    1. The ‘Date of search’ remains the date of the search for which results were fully incorporated.
    2. Studies not yet fully incorporated into the review are added to ‘Studies awaiting classification’.
    3. The 'Search methods' in the abstract should focus on reporting the search dates related to the last fully incorporated studies. Brief mention of a top-up search may be made only if it was conducted for a completed update or new review. Do not refer to scoping searches for updating in the abstract.  
    4. The 'Search methods for identification of studies' in the main text of the review should be used primarily to describe the details of the search for which the results have been fully incorporated, i.e. the dates of individual database searching and the hits retrieved should be based on the search date where results are fully incorporated. If a top-up search has been performed, but the results not yet fully incorporated, the search section may briefly describe this (see example below) and state how many studies have been placed in 'Studies awaiting classification'.
    5. In the 'Results of the search' section the authors should specify the number of studies yet to be fully incorporated into the review. This should also be reflected in the conclusions (both of the main review and the abstract).
    6. The PRISMA flow of studies diagram should also reflect the number of studies in the 'Studies awaiting classification' section.
    7. The 'What’s New' events must describe the number of studies that have been put into 'Studies awaiting classification' if the top-up search is mentioned in the search methods section.
    8. The search appendix should present only database strategies for searches conducted for which results were fully incorporated.
  4. If different databases were searched on different dates, the most recent date of the search for each database should be given within the text of the review and the earliest of these dates should be entered as the ‘Date of Search’. In the case of review updates or 'top-up' searches, if there is clear rationale for not searching one or more of the previously searched databases (e.g. because no unique relevant records were identified in the original/previous search, or the database is no longer being updated), the rationale should be stated within the text of the review. In this case, the 'Date of search' should be the earliest date of the searches performed for this smaller set of databases.


Search types


Full search – results fully incorporated

Electronic search strategies run in full in all relevant databases AND all search results are assessed for eligibility as included, excluded, or ongoing studies. Only if all reasonable efforts to classify search results have failed should they be placed in ‘Studies awaiting classification.’*

Top-up search – results not fully incorporated 

Electronic search strategies run in full in all relevant databases BUT search results are not all assessed for eligibility, instead they are placed in 'Studies awaiting classification'.

Scoping search for updating

Electronic search strategies run in selected databases to determine if an update is required.

*See R6 and R34 in MECIR; and definition of updating.

Examples of reporting top-up searches