In evidence-based medicine, there is emphasis on using high-quality research to inform clinical decision making. To effectively search the literature one must first create an answerable question. Several tools exist to help create answerable questions, the most frequently cited of which is PICO, which stands for population/patient, intervention/indicator, comparison/control, and outcome.
This mnemonic is effective in formulating focused research questions, but using PICO alone to construct a search strategy has some pitfalls. First, the disease concept may not be fully captured by population/patient if one focuses too tightly on demographics. Second, including all four PICO facets as search terms (e.g., adding too many comparisons) can eliminate many relevant results.
One solution is to build research questions using PICO, then extract search terms using the concepts underpinning the Medline database’s tree structure: disease, body part, and process. While disease and body part are largely self-explanatory, process encompasses both interventions (e.g., drugs, surgical techniques) and nonclinical processes (e.g., quality-assurance measures). A question such as “What is the best diagnostic modality in patients with traumatic brain injury?” becomes answerable and more effectively searched when stated: “In patients with suspected TBI (population/disease + body part) what is the diagnostic value of CT (intervention/process) compared with MRI (intervention/process)?”
Whether a literature search is the end of a research process or the beginning of a larger project, College librarians are happy to help you build your search or to search the literature for you. Please contact the College Library for assistance.
This article is the opinion of the Library of the College of Physicians and Surgeons of BC and has not been peer reviewed by the BCMJ Editorial Board.
Above is the information needed to cite this article in your paper or presentation. The International Committee
of Medical Journal Editors (ICMJE) recommends the following citation style, which is the now nearly universally
accepted citation style for scientific papers:
Halpern SD, Ubel PA, Caplan AL, Marion DW, Palmer AM, Schiding JK, et al. Solid-organ transplantation in HIV-infected patients. N Engl J Med. 2002;347:284-7.
About the ICMJE and citation styles
The ICMJE is small group of editors of general medical journals who first met informally in Vancouver, British Columbia, in 1978 to establish guidelines for the format of manuscripts submitted to their journals. The group became known as the Vancouver Group. Its requirements for manuscripts, including formats for bibliographic references developed by the U.S. National Library of Medicine (NLM), were first published in 1979. The Vancouver Group expanded and evolved into the International Committee of Medical Journal Editors (ICMJE), which meets annually. The ICMJE created the Recommendations for the Conduct, Reporting, Editing, and Publication of Scholarly Work in Medical Journals to help authors and editors create and distribute accurate, clear, easily accessible reports of biomedical studies.
An alternate version of ICMJE style is to additionally list the month an issue number, but since most journals use continuous pagination, the shorter form provides sufficient information to locate the reference. The NLM now lists all authors.
BCMJ standard citation style is a slight modification of the ICMJE/NLM style, as follows:
- Only the first three authors are listed, followed by "et al."
- There is no period after the journal name.
- Page numbers are not abbreviated.
For more information on the ICMJE Recommendations for the Conduct, Reporting, Editing, and Publication of Scholarly Work in Medical Journals, visit www.icmje.org