“By-product” Search Results in Systematic Review Searches

Systematic Review (SR) searching adopts both systematic and comprehensive approaches with the goal of retrieving, ideally, all the literature relevant to the focused question at the base of your Systematic Review. Typically, an expert searcher, such as an information professional, uses a combination of keywords qualified with field tags (e.g. [tiab] field tag in PubMed related to title and abstract fields of PubMed records) and subject headings (e.g. MeSH in PubMed and EmTree in Embase) for SR searching.

The MSK Library provides a SR Service to our users

When selecting the terms for an SR, it is best to focus strictly on the terms directly related to the subject or clinical question being addressed. Occasionally it can be appropriate to expand the search to a slightly broader focus to retrieve literature where the exact subject matter may be discussed within the context of other subjects within a broader question.

An example of this expanded search: If the SR is focused on breast cancer surgery, a broader focus would be to look at any/all cancer surgeries wherein breast cancer specific surgery may be discussed.

All search approaches, whether broad or narrow, must be reflected in transparent and reproducible documented search strategies. It is important to remember that there is no “perfect” comprehensive search strategy that will only retrieve relevant citations. It is to be expected that any search, especially a comprehensive SR search, will retrieve many more citations than are actually relevant to the question being asked. Part of the SR process is excluding these irrelevant citations through multiple steps, explained in PRISMA.

However, there is another category besides relevant and irrelevant results, that is typically retrieved – these citations are related to aspects of your topic you did not consider when asking your clinical question and devising your search strategies. These “by-products” might appear important enough that they should be included in your review, but this will be deterring from your original question.

Example: Your SR is on cancer patients’ attitude to health. You devise a comprehensive search strategy and include relevant search terms. As you begin screening the retrieved citations you realize that many of the articles actually focus on health education as it relates to attitudes. You may want to simply add health education as an additional aspect of your SR since it appears to be a valuable aspect of cancer patients’ health attitudes.

The issue with this approach is that unless you backtrack and revise your clinical question and search strategies (and thus essentially starting over from the beginning), your results and conclusions would deviate from the actual question that was proposed initially. If health education was not addressed in your original clinical question and reflected in your search strategies, it would be improper to include it in the final SR as there is likely an entire body of literature that was missed and thus any systematic conclusions could not be made regarding it.

Instead, these “by-product” citations (health education articles that came up in search results for health attitudes) should be treated as irrelevant to the systematic review you are conducting. A potential solution could be mentioning in the discussion section that from this review it was discovered that education is strongly tied to cancer patients’ attitudes toward their disease and their health and that it would be worthwhile to conduct a future review looking at how education can impact these views.

Takeaway: Try not to include “by-product” topics in your final review and analysis.

Retraction Alerts Now in EndNote!

The latest version updates of EndNote 20 — versions 20.2 and 20.3 — now provide retraction alerts thanks to a new partnership between EndNote and Retraction Watch to provide alerts to both references in your library and within Microsoft Word while using Cite While You Write (CWYW).

In order to take advantage of this new feature, you must have an EndNote Online account (free with your desktop version) that you have synced to your EndNote desktop library. NOTE: You can only sync one desktop library to EndNote Online.

For more information and resources on EndNote and other citation management programs, head to the MSK Library’s Citation Management LibGuide. To have EndNote 20 installed on your MSK workstation or your MSK-issued laptop, contact the Help Desk at 123-3337 or 646-227-3337.

Automated MeSH Indexing in PubMed

This year the National Library of Medicine (NLM) is transitioning the process of MeSH indexing in PubMed from manual to automated.

MeSH (Medical Subject Headings) are assigned to MEDLINE citations for the purposes of enriching the metadata and increasing discoverability.

Until 2022 MeSH indexing was done by human indexers at the National Library of Medicine. Starting 2022 human indexers will only oversee and troubleshoot MeSH indexing.

One of the major benefits of automating the process of MeSH indexing is almost instant appearance of MeSH in MEDLINE citations in PubMed. With manual indexing this was delayed for a few months on average. Citations awaiting MeSH indexing were called In Process citations which could be found by keyword searches only.

The downside of automated MeSH indexing, at least in the beginning, could be, potentially, increase in indexing errors. The NLM will be engaged in the ongoing improvement of MeSH indexing algorithm.

Read more about the transition.