Figure 2From: A surveillance system to assess the need for updating systematic reviews The process of surveillance assessment for a Systematic Review. (a) Time elapsed since the search date in the original review. Green color: low priority for updating; Yellow color: medium priority for updating; red color: high priority for updating. (b) Number of new relevant articles identified. Green color: low priority for updating; Yellow color: medium priority for updating; red color: high priority for updating.Back to article page