Documenting search strategy
It is essential to keep track of what you are doing by documenting your search process in enough detail to report it correctly in the review and allow for replicability. There are a number of places where searches can be reported. These include the appendix, the review abstract, the methods section, the results section or as supplementary material.
As with each step of the evidence synthesis review it is important to review and comply with all relevant standards. PRISMA-S is the most common reporting standard for the search process. The PRISMA diagram summarizes the flow of records through the search, screening and synthesis stages.
PRISMA - S
The PRISMA-S (Preferred Reporting Items for Systematic reviews and Meta-Analyses literature search extension) checklist was developed by the PRISMA-S Group as an extension to PRISMA. The goal of the checklist (Table 1) is assisting researchers in documenting their literature searches for systematic reviews and other knowledge syntheses. The checklist identifies what to document in terms of information sources and methods, search strategies, peer review, and records management.
PRISMA-S Checklist |
||
|---|---|---|
Section / Topic |
Item number |
Checklist Item |
Information Sources and Methods |
||
| Database name | 1 | Name each individual database searched, stating the platform for each. |
| Multi-database searching | 2 | If databases were searched simultaneously on a single platform, state the name of the platform, listing all of the databases searched. |
| Study registries | 3 | List any study registries searched. |
| Online resources and browsing | 4 | Describe any online or print source purposefully searched or browsed (e.g., tables of contents, print conference proceedings, web sites), and how this was done. |
| Citation searching | 5 | Indicate whether cited references or citing references were examined, and describe any methods used for locating cited/citing references (e.g., browsing reference lists, using a citation index, setting up email alerts for references citing included studies). |
| Contacts | 6 | Indicate whether additional studies or data were sought by contacting authors, experts, manufacturers, or others. |
| Other methods | 7 | Describe any additional information sources or search methods used. |
Search Strategies |
||
| Full search strategies | 8 | Include the search strategies for each database and information source, copied and pasted exactly as run. |
| Limits and restrictions | 9 | Specify that no limits were used, or describe any limits or restrictions applied to a search (e.g., date or time period, language, study design) and provide justification for their use. |
| Search filters | 10 |
Indicate whether published search filters were used (as originally designed or modified), and if so, cite the filter(s) used. |
| Prior work | 11 | Indicate when search strategies from other literature reviews were adapted or reused for a substantive part or all of the search, citing the previous review(s). |
| Updates | 12 | Report the methods used to update the search(es) (e.g., rerunning searches, email alerts). |
| Dates of searches | 13 | For each search strategy, provide the date when the last search occurred. |
Peer Review |
||
| Peer review | 14 | Describe any search peer review process. |
Managing Records |
||
| Total records | 15 | Document the total number of records identified from each database and other information sources. |
| Deduplication | 16 | Describe the processes and any software used to deduplicate records from multiple database searches and other information sources. |
Table 1 is reproduced here per a Creative Commons Attribution 4.0 International License. Find further explanations and elaborations in the following article: Rethlefsen, M., Kirtley, S., Waffenschmidt, S., Ayala, A., Moher, D., Page, M., & Koffel, J. (2021). PRISMA-S: An extension to the PRISMA Statement for Reporting Literature Searches in Systematic Reviews. Systematic Reviews, 10(1), 39.. https://dx.doi.org/10.1186/s13643-020-01542-z
The PRISMA flow diagram
Regardless of whether an evidence synthesis presents qualitative or quantitative information, reporting out using the PRISMA flow diagram is recommended. The format of the diagram was modified with the adoption of PRISMA 2020 to more easily incorporate additional sources used to identify studies.
Further reading:
Rethlefsen, M., & Page, M. (2022). PRISMA 2020 and PRISMA-S: Common questions on tracking records and the flow diagram. Journal of the Medical Library Association, 110(2), 253-257. https://doi.org/10.5195/jmla.2022.1449
Figure 1 Example of a “PRISMA 2020 flow diagram for new systematic reviews which included searches of databases, registers and other sources” made using the R ShinyApp [1, 6, 7] in Rethlefsen, M., & Page, M. (2022). PRISMA 2020 and PRISMA-S: Common questions on tracking records and the flow diagram. Journal of the Medical Library Association, 110(2), 253-257. https://doi.org/10.5195/jmla.2022.1449 and used with permission under a CC-BY license.