Systematic analysis of hydroxyethyl starch (HES) reviews: proliferation of low-quality reviews overwhelms the results of well-performed meta-analyses.
OBJECTIVE
Hydroxyethyl starch (HES) is a synthetic colloid used widely for resuscitation despite the availability of safer, less costly fluids. Numerous HES reviews have been published that may have influenced clinicians' practice. We have therefore examined the relationship between the methodological quality of published HES reviews, authors' potential conflicts of interest (pCOI) and the recommendations made.


METHODS
Systematic analysis of reviews on HES use.


RESULTS
Between 1975 and 2010, 165 reviews were published containing recommendations for or against HES use. From the 1990s onwards, favorable reviews increased from two to eight per year and HES's share of the artificial colloid market tripled from 20 to 60 %. Only 7 % (12/165) of these reviews of HES use contained meta-analyses; these 7 % had higher Overview Quality Assessment Questionnaire (OQAQ) scores [median (range) 6.5 (3-7)] than reviews without meta-analysis [2 (1-4); p < 0.001]. The rates of recommending against HES use are 83 % (10/12) in meta-analyses and 20 % (31/153) in reviews without meta-analysis (p < 0.0001). Fourteen authors published the majority (70/124) of positive reviews, and ten of these 14 had or have since developed a pCOI with various manufacturers of HES.


CONCLUSIONS
Low-quality HES reviews reached different conclusions than high-quality meta-analyses from independent entities, such as Cochrane Reviews. The majority of these low-quality positive HES reviews were written by a small group of authors, most of whom had or have since established ties to industry. The proliferation of positive HES reviews has been associated with increased utilization of an expensive therapy despite the lack of evidence for meaningful clinical benefit and increased risks. Clinicians need to be more informed that marketing efforts are potentially influencing scientific literature.
Department of Anesthesiology and Intensive Care Medicine, Jena University Hospital, Friedrich-Schiller-University, Erlanger Allee 101, 07747 Jena, Germany.
Christiane S
CS
Hartog
Helga
H
Skupin
Charles
C
Natanson
Junfeng
J
Sun
Konrad
K
Reinhart
D016265:Conflict of Interest; D003245:Consensus Statements as Topic; D004345:Drug Industry; D006801:Humans; D006895:Hydroxyethyl Starch Derivatives / Q000627:therapeutic use*; D015201:Meta-Analysis as Topic; D010952:Plasma Substitutes / Q000627:therapeutic use*; D017410:Practice Guidelines as Topic; D011785:Quality Assurance, Health Care; D012107:Research Design; D012151:Resuscitation / Q000379:methods; D012196:Review Literature as Topic
D006895:Hydroxyethyl Starch Derivatives; D010952:Plasma Substitutes