Coding of clinical trials and systematic reviews in The Cochrane Library using international standards.

Gichuhi S, Hawkins BS, Dickersin K. Coding of clinical trials and systematic reviews in The Cochrane Library using international standards.. Vol. 4. Montreal, Canada: Society of Clinical Trials; 2007.


Registers and databases of reports of clinical trials and systematic reviews are invaluable resources for clinical trialists, health professionals, and consumers. However, their utility in retrieval of information about a particular health condition and/or intervention is limited by variations in terminology used by different medical specialties and researchers. Coding clinical trials and systematic reviews using international coding standards in common use may improve access to and translation of evidence to practice. WHO’s International Classification of Diseases (ICD-10) is used internationally across research and clinical settings and presents a good option. The International Classification of Health Interventions (ICHI) is in beta testing prior to public release and would add additional indexing information.

The Cochrane Library currently includes 4,539 systematic reviews and review protocols and over 470,000 citations to controlled trials. The Library is searched using textwords and MeSH. A project is underway within the Cochrane Eyes and Vision Group (CEVG) to tag vision-related systematic reviews and over 7,000 clinical trials available to the public on The Cochrane Library, with ICD codes for (a) the disease entity(ties) addressed and (b) the intervention(s) evaluated. We present the results of the pilot study.

In our pilot study, two independent reviewers completed coding for 43 CEVG systematic reviews published in The Cochrane Library. Inter-observer agreement using ICD-10 was 81.4%. ICHI was suboptimal for coding of individual medications.

In the next phase of piloting, we will code a subset of trials and compare search results using the current MeSH and textword approach versus the new ICD coding.

Support by NIH contract NO1-EY-2-1003, National Eye Institute, National Institutes of Health.

Published in Clinical Trials, vol 4, issue 4, pg 390


We submitted the abstract in 2006 with me as the first author. Barbara Hawkins read the paper as I had returned to Kenya by the time of the conference.

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