One goal of The Cochrane Collaboration is to present the best current evidence on the effects of health care interventions. This is accomplished by updating published reviews as new evidence becomes available. Review authors are expected to update their literature searches at least every two years, and more frequently if important new evidence is published.

Depending on when the original review was published, expectations of The Cochrane Collaboration in general, and Cochrane Back and Neck (CBN) in particular, may have changed. Please explore the section on Resources for Authors or on the Cochrane Collaboration website for tools to update your review. The lead author should consider the following issues before commencing on an update of the review:

• Are there at least three authors on the review team?

• Is there someone on the team with expertise in methods of systematic reviews and the content area under review (e.g. physician for medications)?

• Are at least two nationalities represented on the team?

• Does the team need new members in order to complete the task?

• Are the inclusion criteria for studies still appropriate? Do they need to be updated?

• Is the search strategy still appropriate or should it be updated?

• Should the review be updated in accordance with updated CBN methodological criteria?

• If no new trials are identified and no changes are requested by the editors or CBN Managing Editor, then the review can be simply updated in RevMan by inserting the date on which the literature search was completed into the 'What's New-dates' section; and indicating in the 'What's New-Notes' section exactly what was done and the results. The updated review should then be forwarded to CBN Managing Editor.

• If new trials are identified, ongoing trials that were identified in the original review have been published, or other changes are required, the review team should analyze the issues outlined above, develop a plan for proceeding, and notify CBN Managing Editor of this plan.

• Review authors should update the review within 6 to 12 months of updating the literature search, depending on the number of new studies to be incorporated and the extent of changes to the manuscript.

• Depending on the extent of changes, the manuscript may be refereed by the same process as a new review. See Publish a Review for details.

Authors who fail to update a review within two years will no longer receive a free copy of The Cochrane Library. In addition, the review may be withdrawn from The Cochrane Library, or the title may be re-assigned to a new team of authors.