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Dragonfly Spring - Summer 2002 -- Volume 33, Number 2

Complementary and Alternative Medicine (CAM) Research Using MEDLINE

By Jane Saxton, MLIS, Library Director
Bastyr University, Kenmore, Washington

This article was originally a handout for a presentation given by Jane Saxton at the 2002 Annual WMLA Meeting. Dragonfly is grateful for the permission to reprint it. A printable version of the handout is at: http://nnlm.gov/pnr/train/cammedline.doc

MEDLINE (http://pubmed.gov) is the world's premier biomedical database. Currently, it indexes around 600 journals relating to the field of complementary and alternative medicine (CAM). The MeSH Browser allows you to explore current Medical Subject Headings by providing definitions of terms and detailed subject hierarchies, or MeSH trees. The MeSH Browser is located on the left sidebar of the PubMed search screen.

• Therapeutics: The broad headings Complementary Therapies, Diet Therapy, Exercise Movement Techniques, Musculoskeletal Manipulations and Physical Therapy Techniques are subsumed here, as well as more specific ones such as:
  
  • Chelation Therapy (under Drug Therapy)
  • Orthomolecular Therapy (under Drug Therapy)
  • Placebos
  • Self Care
    
    
• Complementary Therapies: Enter the phrase in PubMed's MeSH Browser to see the MeSH tree (or subject hierarchy) for this term.
• Some useful subject headings subsumed under the MeSH heading Complementary Therapies are:

  Acupuncture Therapy
  Homeopathy
  Massage
  Medicine, Chinese Traditional
  Mind-Body Relations (Metaphysics)
  Naturopathy
  Phytotherapy
  Psychoneuroimmunology
  Relaxation Techniques
  Sensory Art Therapies

  
  
  
  
• Environment and Public Health: This broad heading includes the more specific headings Environmental Health, Preventive Medicine, and Public Health, which are all disciplines closely related to CAM.
  
  
• Traditional Chinese Medicine (TCM): In November 2001, MEDLINE adopted pinyin to romanize Chinese characters, replacing the outdated Wade-Giles system. For example, the pinyin Qi (the traditional Asian concept of the life force that travels along channels of the body, called meridians) now replaces the Wade-Giles form, Ch'i. Wade-Giles transliterations are associated with the correct pinyin forms in MEDLINE and will still be searched as keywords.
  
  Chinese herbal medicine is an extremely complex field. Some major reasons for this are: 1) different spellings of the English names of herbs abound; 2) certain age-old herbs have many different botanical variations, depending on where the plants are gathered; 3) many herbs are used in combinations, or patent formulations, which set up synergistic effects that are difficult to assign to one plant or another. Standardization and GMP (Good Manufacturing Practice) are also issues. Research interest in Chinese herbs is picking up but, to date, there are very few well-designed research studies of these substances.
  
  Some Chinese herbs are MeSH headings, but most are not. Preliminary research to gather name variations, including the Latin forms, is especially important for Chinese herbal research in MEDLINE. The following MeSH headings and keywords are pertinent. Experiment combining selected ones with the connector OR.
  
  

  MeSH Headings:

  Selected Keywords:

  Medicine, Chinese Traditional -- (includes Qi and Yin-Yang Acupuncture -- (refers to the health profession only) Acupuncture Therapy -- (includes Acupressure, Moxibustion and headings related to theory and practice) Drugs, Chinese Herbal -- Individual names of Chinese herbs that are MeSH headings, e.g. Astragulus Pulse -- (use in conjunction with other headings, such as Medicine, Chinese Traditional or Acupuncture Therapy) Tai Ji tao (or dao)

  Individual names of Chinese herbs (not MeSH) channel or channels -- (use in conjunction with other headings, such as Medicine, Chinese Traditional or Acupuncture Therapy) ch'i -- (still useful as a keyword even though Qi is the new MeSH heading) qi gong, and the alternate spelling qigong* -- Possible spelling variations of this term: (qi or chi or ki) with (kong or gung or kung or gong) tongue diagnosis -- (use in conjunction with the heading Medicine, Chinese Traditional) tuina or tui na *Both qi gong and qigong are associated with the MeSH term Breathing Exercises and will retrieve citations on this broader heading.

• Angiosperms: The MeSH term Herbs was discontinued in January 2002 and was replaced retrospectively in all citations by the botanical term, Angiosperms: "any member of the more than 250,000 species of flowering plants having roots, stems, leaves, …and well-developed conductive tissues…." Many medicinal and nutritional plants are subsumed under the term Angiosperms. (See the section below, Searching Tips for Botanical and Nutritional Substances, for further information on searching under individual plant names.)
  
• Use Phytotherapy for therapeutic aspects: "Use of plants or herbs to treat diseases or to alleviate pain." Phytotherapy, literally "plant therapy," is a new MeSH heading as of January 2002. It was assigned retrospectively to all citations with a heading from the Angiosperms tree that also had the subheading /therapeutic use.
  Antineoplastic Agents, Phytogenic is a more specific term used for anti-cancer agents obtained from "higher plants that have demonstrable cytostatic or antineoplastic activity."
  
• Use Plant Extracts, and the broader term Plant Preparations, for pharmacognosy aspects: "Concentrated pharmaceutical preparations of plants obtained by removing active constituents with a suitable solvent, which is evaporated away, and adjusting the residue to a prescribed standard." The heading Drugs, Chinese Herbal is subsumed under this category.
  
• Use Ethnobotany for anthropological/traditional medicine aspects: "The plant lore and agricultural customs of a people. In the field of medicine, the emphasis is on traditional medicine and the existence and medicinal uses of plants and their constituents, both historically and in modern times."
  
• Use Medicine, Herbal for professional and occupational aspects: "The study of medicines derived from botanical sources." This heading does not apply to the medicinal plants themselves.
  
• Plants, Medicinal is being phased out. This MeSH heading has been used for the medicinal botany aspects: "Plants whose roots, leaves, seeds, bark, or other constituent possess therapeutic, tonic, purgative, or other pharmacologic activity when administered to higher animals." According to one of the MeSH Division indexers, it is "a vague, non-taxonomic leftover that won't be used much anymore." The term Phytotherapy, in combination with the most specific plant (family, genus or species) available in MeSH, will be used instead.

• Individual Plant Names
  Although this is not yet uniform, MEDLINE indexing emphasizes the universal scientific binomial names of plants, rather than common names, which can vary according to geographical location. You should know the various forms of plant names when searching for information on them in MEDLINE. The following site is useful in determining the common or scientific names of many plants: http://www.herbmed.org
  Some medicinal plants are MeSH headings, e.g. arnica, and some are not, e.g. saw palmetto. Some common names are associated with the MeSH heading for the scientific name or genus, e.g. licorice, and some are indexed only under the common name, e.g. comfrey. Plant names that are MeSH headings are searched as subject headings and as keywords. Non-MeSH plant names that are not associated with a MeSH heading are searched only as keywords.
  
  
• Plant Constituents
  Scientific research on medicinal and nutritional plants is performed using whole plants, particular parts of plants, and/or various plant constituents (or chemical components), which are thought to be responsible for the therapeutic or physiological effect of the substance. The major constituent groups are: Alkaloids, Flavones, Essential Oils, Glycosides, Resins, Saponins, Sterols, Tannins, and Terpenes. All of these groups are MeSH headings.

  MEDLINE indexes such research under the common and/or scientific name of the whole plant, and/or under its active constituents. For example, both milk thistle (a plant with well-researched liver-protective properties) and one of its major constituents, silymarin, are MeSH headings, but most of the research is indexed only under the latter term. Genistein and daidzein are both constituents of soybeans and much of the research on soy is indexed under them, either as a MeSH tem or a Substance Name.

  Constituents and whole plants live in separate MeSH trees, or subject areas, that are not linked. Constituents are in the Chemicals and Drugs Category, while whole plants are in Plant Families and Groups.

  With these facts in mind, be creative. Experiment with searches that include some or all of the following, ORing them together: the plant's common name; the plant's scientific name or genus; and/or active constituent(s) specific to that particular plant, or the group of plants to which it belongs, that have been suggested as producing a therapeutic effect.
  For example:
  

  (soybeans OR genistein) AND menopause;
  (licorice OR glycerrhiza OR glycyrrhetinic acid) AND cancer.

  Note: Important constituents can often be identified by entering the plant name in the MeSH Browser and perusing the definition and/or by scanning pertinent abstracts and subject headings, especially the Substance Names list. (See the later section, MEDLINE Fundamentals, for instructions on how to display MeSH headings in addition to abstracts.)
  Print resources are also helpful. See the Botanical Medicine Resources tip sheet, available from the Bastyr University Library, for a bibliography.

• Food and Nutrition
  The MeSH term Food is in the Technology and Food and Beverages Category of MEDLINE and deals with "anything which, when taken into the body, serves to nourish or build up the tissues or to supply body heat." A long list of individual food items that are MeSH headings is subsumed under this term. Nutrition is in the Biological Sciences Category of MEDLINE and covers "the science of food, its action, interaction, and balance in relation to health and disease."
  
  
• Diet and Diet Therapy
  In MEDLINE, the MeSH term Diet is subsumed under the broader heading Nutrition and refers to "the regular course of eating and drinking adopted by a person or animal." The term Diet Therapy, however, is subsumed under Therapeutics. Diet Therapy refers to specific diets prescribed in the treatment of a disease and can also be used as a subheading with specific diseases, e.g. Diabetes Mellitus/diet therapy, Neoplasms/diet therapy.

The National Center for Complementary and Alternative Medicine (NCCAM) and the National Library of Medicine (NLM), both at the National Institutes of Health (NIH), created this subset. This feature is especially useful for finding CAM information on specific health conditions, or to limit concepts such as placebo.

Enter search terms in the PubMed search box, then click the Limits button, open the Subsets menu and select Complementary Medicine.

The Complementary Medicine subset is updated daily, except Sunday and Monday. You can look at the complex search strategy used to identify citations at http://www.nlm.nih.gov/bsd/pubmed_subsets/comp_med_strategy.html.

Caution: The Complementary Medicine subset is generally more useful for health conditions and concepts than for botanical substances, many of which have little research to begin with, or are already included in the subset. Be careful limiting searches on complementary and alternative medicine. Do some preliminary work collecting search terms and then run the search. If you get too many hits, or many that aren't on target, revise your search and consider using a limiting feature such as this Complementary Medicine subset.

Click Clinical Queries on the left sidebar of the PubMed search screen. Choose either Clinical Queries Using Methodology Filters or Systematic Reviews. (Explanations of these options are available on the site.)

Use the following format to enter search terms, where cam [sb] specifies the Complementary Medicine subset:

arthritis AND cam [sb].

You can also search for clinical or review information on botanical and nutritional substances by entering terms such as st john's wort or beta carotene in the search box.

* We thank Andrew Hamilton, of the National Online Training Center, National Library of Medicine, for his insights in developing this CAM search methodology.

Natural language text words and phrases are especially useful when researching CAM topics. MEDLINE automatically compares phrases to a Phrase Index. If the phrase you enter is not found, MEDLINE will break the terms apart, combine them with AND and search for them separately. Examples of natural language search terms are:

• Boolean Operators: Always enter the connecting words AND, OR and NOT in capital letters.
  AND: Finds only citations with both terms
  OR: Finds citations with either or both terms
  NOT: Excludes citations containing the specified term(s)
  Note: The connecting word NOT is a "blunt instrument, a mallet, not a scalpel" according to Andrew Hamilton, a librarian with the National Online Training Center (NLM). For example, the search aids NOT tuberculosis eliminates a wealth of articles that discuss both conditions. It is usually better to limit a concept by adding more terms using the connector AND than to exclude a concept by using NOT.
  
  
• Word Order: MEDLINE processes search queries from left to right. Word order is important if you are connecting some terms with OR. Use parenthesis around ORed terms to tell MEDLINE to "do this first." For example: cancer AND (soybeans OR genistein).
  
  
• Subheadings: Combining MeSH terms with appropriate subheadings, such as the following, will produce more specific results: adverse effects; contraindications; diet therapy; therapeutic use. MEDLINE recognizes subheadings only when entered in the following format: MeSH heading/subheading. However, the MeSH Browser will add subheadings for you. First, locate a subject heading in the MeSH Browser, then click on [Detailed Display] next to the term. The range of possible subheadings for that term will appear. Select the ones you'd like to add to the search term, choose AND, OR or NOT from the menu provided, and click Add this term/subheadings to the Search using operator. This inserts the terms into the PubMed search box. Click the gray PubMed Search button to run the search.
  Note: Use subheadings when they are the only way to explain the relationship between search terms, or when you are certain you only want citations for one aspect of a broad subject. Subheadings limit MeSH to one specific aspect, and also "turn off" the keyword search capability, which picks up citations that don't have MeSH headings yet.
  
  
• Details: Click on the Details button under the PubMed search box after running each search to make sure MEDLINE is interpreting your terms correctly. MEDLINE ignores misspelled words, and words entered after connectors or parentheses that have been entered incorrectly.
  
  
• Displaying Subject Headings: MeSH headings can only be viewed in MEDLINE records by changing the display to either Citation or MEDLINE format. To find out how to change the display format, click the PubMed Help button on the lefthand sidebar and find the topic Display, under Documents.
  
  
• Automatic Mapping: MEDLINE compares or "maps" search terms to the following indexes in this order: MeSH terms, Journal Titles, Phrase Index, Author Index. If it doesn't find the terms in any of these places, it will search the terms separately, combining them with AND.
  
  
• Quotation Marks: Placing quotation marks around search terms tells MEDLINE to "keep the terms together" if it finds the phrase in the PubMed Index. If the phrase is not found, the words are ANDed together and searched separately. Use quotation with care because they "turn off" the automatic mapping feature of the database and you may miss some pertinent citations.
  
  
• Truncation: The truncation feature ( * ) allows you to retrieve varient forms of a word. For example, vitamin* retrieves vitamin, vitamins, and vitaminology. The truncation symbol also "turns off" the automatic mapping feature and you may miss some pertinent citations.
  

Dragonfly, Spring - Summer 2002 - Volume 33, Number 2
(posted on PNRNews on May 30, 2002)

This publication is funded in whole with Federal funds from the National Library of Medicine, National Institutes of Health, under Contract No. N01-LM-1-3516.

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NN/LM | UW HSL | NN/LM PNR | Contact us: nnlm@u.washington.edu | Revised: September 5, 2002

URL: http://nnlm.gov/pnr/news/200204/cammedline.html