Archive for November, 2009

If you had to cancel a health database today? Evidence-based decision-making vs. Hobbesian elbowing

Trying to decide on a database cancellation can be fraught with uncertainty.  Evidence-based criteria are important but often shoved out of the way by other considerations. The culling process is a little more sophisticated than resorting to eeny, meeny, miny, moe. Basing decisions on research is laudable, but in the end it’s dollars and a Hobbesian political deftness that count for more. It’s not a case of evidence-be-damned, but rather the Ellenbogengesellschaft – the sharp-elbowed social reality – of collection development.

Consider the following databases: AMED (Allied and Complementary Medicine Database), CINAHL, EMBASE, and Global Health. If you had to cancel one of them, which would it be? The latter might get the boot from some of us, but I’m guessing most health libraries would probably push AMED overboard first. We would justify this to ourselves with the comforting assumption that the combination of the other databases provides good enough coverage of complementary and alternative medicine. CINAHL, for example, is well known for its lavish attention to allied health; PubMed offers its petal-strewn Complementary Medicine subset to smooth the way for us; and so on. And isn’t it true that in the minds of many faculty and health professionals CAM is to real medicine what holy water is to healing? That, to me, is the key issue. Always present in the background of a library’s cancellation decision is one of the guiding principles of a public service, multa docet fames (hunger teaches us many things). Regardless of what the literature tells us, this question cannot be avoided: to which database’s disappearance would the most influential library patrons object least?

Some justly claim their decisions to be reasoned and evidence-based. Others, if pressed, might have to admit that a decision can be biased, gratuitous, hasty, or obviously political. Journal and database cancellations are determined centrally in my world, and hence are mostly out of my hands. I like to think that the best reasons, and not just sharp elbows, are always brought forward before a subscription is dropped. Be that as it may, with respect to CAM resources, a Canadian study [1] has succeeded in undermining most of my notions about the quality and comprehensiveness of PubMed’s coverage of complementary and alternative medicine. I also see AMED in a new light.

AMED acclaimed
In a recently published article in Evidence-based complementary and alternative medicine, the authors’ objective was to compare a number of databases relevant to CAM. In all, they searched fifteen databases to identify CAM controlled clinical trials not also indexed in MEDLINE.

Their abstract sums things up adequately:

Searches were conducted in May 2006 using the revised Cochrane highly sensitive search strategy (HSSS) and the PubMed CAM Subset. Yield of CAM trials per 100 records was determined, and databases were compared over a standardized period (2005). The Acudoc2 RCT, Acubriefs, Index to Chiropractic Literature (ICL) and Hom-Inform databases had the highest concentrations of non-MEDLINE records, with more than 100 non-MEDLINE records per 500. Other productive databases had ratios between 500 and 1500 records to 100 non-MEDLINE records-these were AMED, MANTIS, PsycINFO, CINAHL, Global Health and Alt HealthWatch. Five databases were found to be unproductive: AGRICOLA, CAIRSS, Datadiwan, Herb Research Foundation and IBIDS. Acudoc2 RCT yielded 100 CAM trials in the most recent 100 records screened. Acubriefs, AMED, Hom-Inform, MANTIS, PsycINFO and CINAHL had more than 25 CAM trials per 100 records screened. Global Health, ICL and Alt HealthWatch were below 25 in yield. There were 255 non-MEDLINE trials from eight databases in 2005, with only 10% indexed in more than one database. Yield varied greatly between databases; the most productive databases from both sampling methods were Acubriefs, Acudoc2 RCT, AMED and CINAHL.

Not unexpectedly, in their conclusion the authors recommend a multi-database approach:

The very low overlap between … non-PubMed sources suggests the need for multiple database searching in addition to MEDLINE in order to comprehensively search for CAM controlled trials. The results indicate that of the six databases analyzed that are not focused on a specific therapy, CINAHL was the most productive, followed by AMED. The Acubriefs and Acudoc2 RCT databases were highly productive for acupuncture trials.

With budget restrictions looming, the University of Manitoba Libraries has just dumped AMED, which this study identifies as second only to CINAHL for controlled clinical trials coverage in complementary and alternative medicine. Who would have guessed that AMED would stand out in this subject area, considering how poorly it is rated in another recent study which has just been published in Physiotherapy [2]?

AMED def-amed
Researchers at the University of Sydney compared the comprehensiveness of indexing the reports of randomized controlled trials of physiotherapy interventions by eight bibliographic databases (AMED, CENTRAL [Cochrane], CINAHL, EMBASE, Hooked on Evidence, PEDro, PsycINFO and PubMed). The results in a nutshell? PEDro indexed 99% of the trial reports, CENTRAL indexed 98%, PubMed indexed 91%, EMBASE indexed 82%, CINAHL indexed 61%, Hooked on Evidence indexed 40%, AMED indexed 36% and PsycINFO indexed 17%.

Poor AMED comes a cropper here, outclassed as it is by a free resource like PEDro (a name almost as silly as Acubriefs, which sounds like the latest offering from Stanfield’s Ltd., Canada’s self-proclaimed, one-and-only “Underwear Company”). A library might feel quite justified in cancelling its subscription after reading about AMED’s poor coverage of physiotherapy research.

Given these contrasting evaluations of a database’s effectiveness, the question arises as to which evidence will have the most weight in the decision to cancel or retain? Our pair of studies illustrate how difficult it can be to play the database shuffle in making cancellation decisions. When budgets are tight and sacrifices must be made librarians are always ready to lend a hand, but attached to those hands should be sharp elbows.


References

1. Cogo E, Sampson M, Ajiferuke I, Manheimer E, Campbell K, Daniel R, Moher D. Searching for controlled trials of complementary and alternative medicine: a comparison of 15 databases. Evid Based Complement Alternat Med. 2009 May 25. PubMed PMID: 19468052. DOI 10.1093/ecam/nep038.

2. Moseley AM, Sherrington C, Elkins MR, Herbert RD, Maher CG. Indexing of randomised controlled trials of physiotherapy interventions: a comparison of AMED, CENTRAL, CINAHL, EMBASE, hooked on evidence, PEDro, PsycINFO and PubMed.Physiotherapy. 2009 Sep;95(3):151-6. Epub 2009 Apr 23. Review. PubMed PMID: 19635333.

Photo credit: CC licensed flickr photo by fabbio:  http://flickr.com/photos/fabiovenni/240530154/

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