Elizabeth Ketterman, MLS
Laupus Health Sciences Library
East Carolina University
Greenville, NC 27834
Megan E. Besaw, MLIS
Laupus Health Sciences Library
An Evaluation of DynaMed and UpToDate
East Carolina University
Greenville, NC 27834
An Evaluation of Citation Counts, Search Results, and Frequency of Updates in DynaMed and
UpToDate
INTRODUCTION
The amount of medical literature expands at a rate of over 2 million articles each year in the fields of medicine and science.
1 Despite this rapid pace, physicians and other health care providers are expected to stay current with medical information and apply it in clinical practice to make the best evidence-based decisions for their patients. A study in BMJ from 2002 indicated that the major factors affecting a clinician's ability to provide evidence-based answers
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An Evaluation of DynaMed and UpToDate to their clinical questions were time, lack of topical answers in currently available resources, and a lack of synthesized data from multiple information sources.
2 Resources that attempt to bridge the gap between these frequently occurring barriers are becoming more prevalent at the patients’ bedside.
Point-of-care reference resources have emerged as important tools in a clinician’s information arsenal, in that they summarize and organize these millions of articles worth of data into an electronic ready-reference format. In these kinds of resources, topics are summarized and recommendations made so that a clinician can be updated on the spot, at the point-of-care.
Not all of these resources are the same, however. The products vary in their scope of coverage, specialty areas, citation analyses, and timeliness of updates.
Previous studies have examined various aspects of differing point-of-care tools. Hoogendam and colleagues conducted a comparison of the use of UpToDate and PubMed by 70 physicians in internal medicine.
3 The physicians’ patient-centered questions were answered more frequently in UpToDate than in PubMed. Another study compared UpToDate to the National
Guidelines Clearinghouse and indicated that UpToDate contained a greater breadth of medical topics when assessed when answering clinical inquiries.
4 Additionally, a study of 46 clinicians determined that 54.3% of clinical decisions were changed due to the results of a DynaMed search.
5
The current study examines two point-of-care products: EBSCO’s DynaMed and Wolters Kluwer
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An Evaluation of DynaMed and UpToDate
Health’s UpToDate. According to DynaMed’s about us page, the resource contains, “...clinicallyorganized summaries for more than 3,000 topics,” and, “DynaMed is the only evidence-based reference shown to answer most clinical questions during practice.” This information is updated daily.
6 UpToDate’s About Us page indicates it, “... covers over 8,300 topics in sixteen medical specialties and includes more than 97,000 pages of text,” and, “...our physician editors and authors review and update our content continuously. An updated version of UpToDate is released every four months”.
7 These two resources were evaluated based on four criteria: whether or not there was an initial result for the clinical query, whether or not there was an exact hit for the search, the number of references used in the topic, and the last given update.
METHODS
First, a literature search was conducted in MEDLINE, CINAHL, Library Literature and Information
Science Full Test and LISA: Library and Information Science Abstracts databases. This was done to rule out any recent comparison of these two databases evaluating similar criteria. Next, in order to develop the best statistics possible for the outcomes of the study, East Carolina
University’s Biostatistics department was consulted. A faculty member was assigned to help develop the correct procedures for organizing the searches.
A list of topic searches was developed. It was important to choose topics that would emerge in routine clinical practice; therefore, topics were pulled from the list of clinical queries available from the Journal of Family Practice website.
8 Clinical Inquiries topics are developed by
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An Evaluation of DynaMed and UpToDate physicians who are part of the Family Practice Inquiry Network.
9 From this list, a total of 141 of the most recent topics were generated, the oldest topic dated July 1, 2006. Some topics were discarded when it became clear that a point-of-care resource would not be an appropriate place to search for an answer (ex. “Does reducing smoking in the home protect children from the effects of secondhand smoke?”.) Since both DynaMed and UpToDate use keyword searching, keywords were culled from the clinical queries and searched in both databases over a period of two days.
It is worth further defining each of the four criteria evaluated. For purposes of this study:
 The “initial result count” was the number of results each keyword search retrieved. The authors became aware at this point that DynaMed retrieved an unlimited number of initial results whereas UpToDate retrieved up to 150.
 An “exact hit” indicated whether or not the database returned a result that answered the clinical question. The determination of what constituted an answer to the clinical question was made to the best of the abilities of the librarian authors.
 The number of references used in a topic was a count of how many references were cited within the topic for the result. If the answer for the clinical query was satisfied by the entire topic review, the entire citation count for that review was included. If a section within the topic answered the clinical query, the section citation count was included.
 The last given update was recorded. In both DynaMed and UpToDate, the last given update appears near the top of the topic review screen.
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An Evaluation of DynaMed and UpToDate
The clinical inquiries were assessed based on the above areas and then entered in an Excel spreadsheet. Multiple statistical analyses were run, including chi-square tests.
RESULTS
DynaMed returned a total result count of 20001 of the 141 attempted searches. UpToDate produced an initial result count of 16179. Overall, UpToDate has a greater number of instances
(63.8%) where the initial result count is higher than DynaMed (36.2%). The mean for DynaMed was 141.85 and 114.74 for UpToDate. The p-value of the paired t-test is .075 indicating that the initial result counts for DynaMed and UptoDate are not significantly different. A Wilcoxon
Signed Ranks test comparing the medians also indicated that there is no significant difference as well.
The percentage of an exact hit was slightly higher for UpToDate (89.4%) compared to DynaMed
(87.2%). The chi-square test and McNemar test indicated that there is no significant difference in the chance of an exact hit when comparing the two databases.
The total number of references for the 141 search attempts in DynaMed was 2250 and
UpToDate was 1519. UpToDate has a higher number of instances (74) where it is more likely to provide more references when compared to DynaMed (55) (12 tied). A paired t-test and
Wilcoxon Signed Ranks test indicates that the mean and median of the references are
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significantly greater in UpToDate.
An Evaluation of DynaMed and UpToDate
DynaMed is more likely to provide information that is more current. DynaMed returned with a more current topic 123 times, whereas UpToDate was more current 13 times.
CONCLUSION
The results of the study suggest that of the four areas evaluated, two indicate a statistical advantage of one database over the other. The currency of updates appears to be the major difference between the two databases. Although DynaMed has more current updates,
UpToDate had a more significant total number of references used in a topic. The other two criteria did not produce a statistically significant difference. Deciding between the two databases would have to be left up to personal preference and financial means. If provided with the option, the use of multiple databases is ideal when attempting to thoroughly address clinical questions.
If this study were conducted again, the authors recommend using MeSH headings as keyword searches in each database. It is also recommended, that all searches should be accomplished in one day in order to maintain the integrity of the comparison of the searches. Although the addressing of a clinical query was evaluated, the content or usability of the retrieved information was not.
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An Evaluation of DynaMed and UpToDate
Future research on point-of-care databases, such as DynaMed and UpToDate should continue, especially since many questions remain regarding this particular type of resource. Potential studies could include a comparison of levels of evidence in similar topics, an evaluation of the currency of cited references in similar topics, or the quality of content of the topics. Studies that further evaluate these types of resources would be of benefit to both medical librarians and health care practitioners.
References
1. Baier LA, Wilczynski NL, Haynes RB. Tackling the growth of the obesity literature: Obesity evidence spreads across many journals Int J Obes (Lond). 2009.
2. Ely JW, Osheroff JA, Ebell MH, et al. Obstacles to answering doctors' questions about patient care with evidence: Qualitative study. Br Med J. 2002;324:710.
3. Hoogendam A, Stalenhoef AF, Robbe PF, Overbeke AJ. Answers to questions posed during daily patient care are more likely to be answered by UpToDate than PubMed. J Med Internet
Res. 2008;10:e29.
4. Fenton SH, Badgett RG. A comparison of primary care information content in UpToDate and the national guideline clearinghouse. J Med Libr Assoc. 2007;95:255-259.
5. Alper BS, White DS, Ge B. Physicians answer more clinical questions and change clinical decisions more often with synthesized evidence: A randomized trial in primary care. Ann Fam
Med. 2005;3:507-513.
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An Evaluation of DynaMed and UpToDate
6. What is DynaMed? Available at: http://www.ebscohost.com/dynamed/what.php
. Accessed
7/19/2010, 2010.
7. UpToDate Inc. Available at: http://www.uptodate.com/home/about/index.html
. Accessed
7/19/2010, 2010.
8. The Journal of Family Practice Available at: http://www.jfponline.com/CollectionContent.asp?CollectionID=62&UID . Accessed 7/14/2010,
2010.
9. CI Overview Available at: http://web.memberclicks.com/mc/page.do?sitePageId=71526&orgId=fpin . Accessed
7/14/2010, 2010.
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