title: Type of evidence behind point-of-care clinical information products: a bibliometric analysis.
abstract: BACKGROUND
  Point-of-care (POC) products are widely used as information reference tools in the clinical setting. Although usability, scope of coverage, ability to answer clinical questions, and impact on health outcomes have been studied, no comparative analysis of the characteristics of the references, the evidence for the content, in POC products is available.
  
  
  OBJECTIVE
  The objective of this study was to compare the type of evidence behind five POC clinical information products.
  
  
  METHODS
  This study is a comparative bibliometric analysis of references cited in monographs in POC products. Five commonly used products served as subjects for the study: ACP PIER, Clinical Evidence, DynaMed, FirstCONSULT, and UpToDate. The four clinical topics examined to identify content in the products were asthma, hypertension, hyperlipidemia, and carbon monoxide poisoning. Four indicators were measured: distribution of citations, type of evidence, product currency, and citation overlap. The type of evidence was determined based primarily on the publication type found in the MEDLINE bibliographic record, as well as the Medical Subject Headings (MeSH), both assigned by the US National Library of Medicine. MeSH is the controlled vocabulary used for indexing articles in MEDLINE/PubMed.
  
  
  RESULTS
  FirstCONSULT had the greatest proportion of references with higher levels of evidence publication types such as systematic review and randomized controlled trial (137/153, 89.5%), although it contained the lowest total number of references (153/2330, 6.6%). DynaMed had the largest total number of references (1131/2330, 48.5%) and the largest proportion of current (2007-2009) references (170/1131, 15%). The distribution of references cited for each topic varied between products. For example, asthma had the most references listed in DynaMed, Clinical Evidence, and FirstCONSULT, while hypertension had the most references in UpToDate and ACP PIER. An unexpected finding was that the rate of citation overlap was less than 1% for each topic across all five products.
  
  
  CONCLUSIONS
  Differences between POC products are revealed by examining the references cited in the monographs themselves. Citation analysis extended to include key content indicators can be used to compare the evidence levels of the literature supporting the content found in POC products.
authors.affiliation: Health Sciences Library System, University of Pittsburgh, Pittsburgh, PA, USA. ketchum@pitt.edu
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Ketchum
authors.forename: Ahlam A
authors.initials: AA
authors.lastname: Saleh
authors.forename: Kwonho
authors.initials: K
authors.lastname: Jeong
mesh_terms: D015706:Bibliometrics; D054626:Consumer Health Information; D003625:Data Collection; D016208:Databases, Factual; D019317:Evidence-Based Medicine; D006801:Humans; D008490:Medical Informatics; D019095:Point-of-Care Systems; D013223:Statistics as Topic