Reviewing recent credible medi-cal studies is essential to the practice of evidence-based medicine, which may be defin-ed as “the integration of best research evidence with clinical expertise and patient values.” A question that frequently arises at the College of Physicians and Surgeons of British Columbia library from doctors conducting searches to support their practice is, “What is the difference between a systematic review and a meta-analysis?”
Systematic reviews address a focused and answerable clinical question, have explicit search methodology, and attempt to examine the whole range of studies conducted on a particular clinical question. This ensures more reliable evidence than a standard narrative review article as the systematic review is comprehensive, grapples with ambiguities and conflicting results, and presents a bottom-line interpretation. Occasionally the conclusion reached is “not enough evidence is available to answer the question,” which may be a valuable conclusion in itself.
Meta-analyses merge the evidence found in studies considered in systematic reviews after managing such issues as heterogeneity between the studies. By analyzing this larger pool of evidence using statistical methods, more powerful conclusions may be drawn. In addition, inconclusive evidence and inconsistencies between studies may be examined in greater detail.
Well-designed systematic reviews and meta-analyses offer the highest levels of evidence on clinical questions and are found in various databases such as MEDLINE, Clinical Evidence, and the Cochrane Library. All of these databases are available for free to college registrants through the College Library (www.cpsbc.ca/library/search-materials/databases).
This article is the opinion of the Library of the College of Physicians and Surgeons of BC and has not been peer reviewed by the BCMJ Editorial Board.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