Skip to main content

Archived Comments for: The "Statinth" wonder of the world: a panacea for all illnesses or a bubble about to burst

Back to article

  1. Alternative explanation for decline in statin studies

    An-Wen Chan, Dept of Medicine, University of Toronto

    17 August 2005

    Shafiq and colleagues present an interesting review of the many postulated indications for statins in healthcare. We would like to comment briefly on their hypothesis and conclusion that statin research may be on the decline. This assertion was based on an apparent decline in the number of annual citations identified on PubMed, from over 1600 citations in 2003 to fewer than 1200 citations in 2004.

    We have an alternative explanation for the presumed decline in citations identified from 2004. The indexing date of citations on PubMed falls well behind the actual publication dates in journals. For example, we conducted repeated PubMed searches for clinical trials published in December 2000, and found that citations identified from identical search strategies continued to be added to the database up until our last search date in July 2002 (ie. sixteen months after publication). The PubMed search by Shafiq et al would have been conducted prior to February 7, 2005, as this corresponds to the submission date of their manuscript for publication. This search date would allow only 1–13 months for studies to be indexed on PubMed.

    We also performed a quick PubMed search (“statins OR *statin”) for entries indexed from February 7 to August 2005, and identified 101 citations published in 2004. These would have been missed in their paper.

    Therefore, the relatively low number of citations observed by Shafiq et al for the year 2004 is likely an underestimate, as citations will continue to be added to PubMed. Repeated literature searches over the next year would likely identify additional studies and provide a more accurate estimate of the true prevalence of statin research published in 2004.

    An-Wen Chan & Douglas G Altman (Centre for Statistics in Medicine, Oxford)

    Competing interests

    None

Advertisement