PubMed Clinical Queries in Action

To further demonstrate searching with PubMed Clinical Queries let’s review a second case scenario.

Case Scenario #2
Eric is a twenty-seven-year-old bartender who has used chewing tobacco for 9 years. He is a frequent user who chews almost five hours a day. Eric knows he can’t quit by will power alone because he has tried in the past. He wants to know if using a nicotine patch rather than behavioural counselling can help him permanently quit.

To locate the highest level of evidence, begin with the Clinical Queries feature (Figure 17) by typing in the main problem of interest, chewing tobacco cessation. In this case we also will combine it with the Intervention, nicotine patch, and the Comparison, behaviour counselling, using the "and" Boolean operator.

Figure 17. Search Results for Chewing Tobacco Cessation, Nicotine Patch and Behaviour Counselling.


The results of the search identified 8 Systematic Review and 33 citations under Clinical Study Categories.

In reviewing the title of the citations it should occur to the user that perhaps ‘chewing tobacco’ is not the correct indexing term since ‘smokeless tobacco’ is used and nowhere is ‘chewing tobacco’ used in the title of any citation. This becomes critical if no Systematic Reviews are found that answer your question. If that were the case, then you would search the MeSH Database to determine the correct term and discover that chewing tobacco cessation does not find any items but ‘smokeless tobacco’ does and is the correct indexing term in the MeSH hierarchy (Figure 18).

Figure 18. MeSH Database Search for Smokeless Tobacco.


Based on using the MeSH term ‘smokeless tobacco’ a new search query is run and 6 Systematic Reviews and 18 citations for Clinical Study Categories are identified (Figure 19). Notice that the second citation, the 2015 Cochrane Systematic Review, appears to be an update of earlier reviews in 2011 and 2007. Cochrane is considered the gold standard for conducting systematic reviews so this reference would be a good place to start to see if there is an answer to your questions.

Figure 19. Results of Search for Smokeless Tobacco Cessation and Nicotine Patch and Behaviour Counselling.


As demonstrated, there is no one correct way to conduct a search and for someone who is not familiar with Boolean operators and combining terms, the filters feature or the MeSH database, the Clinical Queries feature is an excellent starting point. For example, if the Clinical Queries search just included “chewing tobacco cessation,” 80 Systematic Reviews citations are identified (Figure 20), however these do necessarily focus the search on the chief concern of Eric, which is the effectiveness of the nicotine patch as compared to behavioural counselling on quitting chewing tobacco.

Figure 20. Results of Search for Chewing Tobacco Cessation.


To narrow the 80 Systematic Reviews, scan down the page and click on See all (80) to apply filters. It brings up all 80 citations on the Results page and by selecting the Publication dates filter, you can identify those published within the last 5 years, narrowing the results from 80 to 20 citations (Figure 21). In scanning through the titles of the 20, you see that some focus on “smoking” cessation vs. chewing or smokeless tobacco cessation. In this case you can add “NOT smoking cessation” to your search. This reduces the number from 20 to 7 abstracts (Figure 22), which is much more realistic to review. However, there’s no guarantee that any of the abstracts address the real problem of whether a nicotine patch will be more effective than behavioural counselling in helping Eric permanently quit using smokeless tobacco.

Figure 21. Clinical Queries Search Results with 5 Year Limit and BEFORE adding NOT smoking cessation.


Figure 22. Results of Clinical Queries Search AFTER adding NOT to Search.

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