The use of PubMed has increased these days by those not just in the field of research and medicine. While this may sound good, just attaching a link to the search results for [insert topic] could be likened to taking two coconut halves and banging them together in an attempt to sound like a legit horse…
And now for a blog episode of ‘Alison Ruins Everything’, I present an example I recently came across: https://www.ncbi.nlm.nih.gov/pubmedhealth/?term=cinnamon. While the intentions of sharing these PubMed search results were in hopes to substantiate benefits of using cinnamon essential oil, this is what the first result had to say about the systematic analysis of cinnamon for diabetes mellitus. (Systematic analysis means the comprehensive review of all current and relevant studies).
Generally, studies were not well conducted and lacked in quality. The review authors found cinnamon to be no more effective than placebo, another active medication or no treatment in reducing glucose levels and glycosylated haemoglobin A1c (HbA1c), a long‐term measurement of glucose control. None of the trials looked at health‐related quality of life, morbidity, death from any cause or costs. Adverse reactions to cinnamon treatment were generally mild and infrequent. Further trials investigating long‐term benefits and risks of the use of cinnamon for diabetes mellitus are required. Rigorous study design, quality reporting of study methods, and consideration of important outcomes such as health‐related quality of life and diabetes complications, are key areas in need of attention. (Cochrane Database of Systematic Reviews)
PubMed is a great tool when you know how to use it correctly. Otherwise, it’s more like using a dull knife which has a high chance of slipping and slicing your own finger. Saying this, even I don’t know how to use it responsibly so I often turn to an expert who uses PubMed on a nearly daily basis and just so happens to be sitting on the couch next to me! Together, we’ve developed this post on what is and how to use PubMed effectively by and for the average person.
What is PubMed?
One giant online database,”PubMed is a free [online] resource that provides access to MEDLINE, the National Library of Medicine database of citations and abstracts in the fields of medicine, nursing, dentistry, veterinary medicine, health care systems, and preclinical sciences.” (1)
It generally does not contain full-text articles but instead provides citations and abstracts of journal articles. Access to the complete journal and/or article may or may not be accessible due to a paywall but those in the research and/or medical fields gain access to full articles through the university or hospital they work at or through a personal subscription to the journal. PubMed Health is a specialized sub-database of PubMed for patients and clinicians to use in order to find information and research on medical topics. Searching for the topic of cinnamon in PubMed brought up up 1,977 search results, whereas PubMed health narrowed it down to a measly 11.
PubMed and it’s sub-databases are awesome! But sometimes it can be like searching for a book in the Library of Congress IN THE DARK. You’ve got to know where and how to look in such a vast array in order to find what you’re looking for. So, how does one navigate PubMed? By knowing what to type into the search bar.
How to search PubMed
Questions like, “What to make for dinner with leftover chicken” or “show times for Thor: Ragnarok” (which was awesome, btw) is how one can phrase search queries in Google but not PubMed.
One useful method is called the PICO method and is taught to medical students:
P: Patient or population that is being treated/intervention is being applied to? (ex. anxiety in middle-aged women)
I: Intervention or treatment of interest? (ex. use of lavender essential oil)
C: Comparison? (ex. SSRI anti-depressant)
O: Outcome? (ex. reduction in anxiety symptoms as measured by a standardized scale such as the Hamilton anxiety scale)
Once you have determined the answers to these questions, you can formulate your search phrase. Our mouthful example would be “middle-aged female lavender essential oil selective serotonin reuptake inhibitor Hamilton anxiety scale”. Note that we did not use the acronym SSRI as PubMed searches do not handle acronyms well.
This specific search brought up one paper, demonstrating how being specific in our search parameters worked wonders!
We threw a stick for our PubMed pup to fetch. Did it bring back a good stick or a smelly sock? Here is the result: https://www.ncbi.nlm.nih.gov/pubmed/?term=middle+age+female+lavender+essential+oil+selective+serotonin+reuptake+inhibitor+hamilton+anxiety+scale
This paper evaluated an oral preparation of lavender oil called Silexan against placebo and an SSRI, known as paroxetine, in a randomized, double-blind, double-dummy trial of 539 adults (primarily women) with generalized anxiety disorder over a ten-week period. The study identifies that Silexan is significantly more effective at reducing anxiety symptoms as compared to a placebo and had a greater overall effect than that which was seen with paroxetine. As with any study, replication is the gold standard for confidence in a finding but this study does pose an interesting insight into the potential benefits of some essential oils. It also precisely addresses our example question of interest.
When using the PICO method, if no results are identified, the query can be simplified or altered to allow broader results. If too many results are identified, more specific terms can be included. The method is intended to provide a handful of results that clearly address the question of interest.
MeSH stands for “medical subject headings” and is one way PubMed indexes common search terms into a hierarchical format. It’s like a medical thesaurus. If your search includes a topic such as heart diseases, MeSH will help by pulling together relating results such as endocarditis, arrhythmias, pericarditis, etc. You can search the MeSH database here and see all the crazy complex medical terms doctors must memorize and use.
Another option in MeSH is to assist you in building a search based on subheadings. Say one’s topic is Rheumatoid Arthritis. These are the many subheading options:
Overall, how is MeSH useful? It helps “to facilitate search retrieval by eliminating (or accounting for) the use of variant terminology for the same concept.” (2) Rather than having to perform several searches with similar terms, including spelling variations, using medical subject headings can pull in all those similar search terms.
When using PubMed, it is important to be concise and descriptive. Develop your search parameters by using the PICO method to efficiently narrow your results. MeSH is a useful net for reducing multiple searches by drawing in similar medical terminologies and spellings.
Keep asking questions and learning new things. As Miss Frizzle always says, “Take chances, make mistakes, get messy!”