Introduction
Evidence and gap maps (EGMs) are a visual representation of the available evidence relevant to a specific research or topic area. The studies that populate EGMs are identified using robust systematic search methods, usually across several databases, using a variety of search methods. To remain current and useful, EGMs should be updated at intervals to reflect the current literature landscape. Search summary tables (SSTs) produced at the end of the initial search process can help to streamline the update process by identifying which methods and resources are the most valuable for any given topic.
Aim
To demonstrate the usefulness of SSTs in updating evidence reviews through 2 case studies using EGMs.
Method
SSTs were produced for 2 unrelated EGMs: peer support interventions and intergenerational activities. The SSTs were used to determine (1) which databases returned the most included studies, (2) which databases returned unique studies, (3) which databases returned no useful studies, (4) which databases returned the most robust evidence, and (5) the value of supplementary search methods.
Results
Analysis of the SSTs for both projects indicate the value of a small selection of databases in returning randomized controlled trials, qualitative studies, and unique hits. In the peer support interventions project, forward citation chasing was a valuable supplementary search method. For the intergenerational activities project, backward citation chasing was lucrative, together with hand-searching specific journal titles.
Conclusion
The 2 case studies demonstrate the value in using SSTs to accompany EGMs, in particular "living" EGMs, to streamline the update process and to ensure that choices about resources in systematic searching are evidence-based.