Sunday, May 02, 2010

CDISC beyond the data

CDISC stands for the Clinical Data Interchange Standards Consortium. I have always been thinking that the CDISC is about the data standard and data structure and has nothing to do with the protocol, case report form and so on.

However, for the last several years, CDISC has expanded its reach into the entire flow of the clinical trial. For each step in clinical trial, there is its counterpart in CDISC standard.

  • Protocol: Protocol representation model (PRM)
  • Case Report Form: The Clinical Data Acquisition Standards Harmonization (CDASH)
  • Data management data set: The Study Data Tabulation Model (SDTM)
  • Analysis data set: Analysis data model (ADaM)
The protocol representation model is pretty new and is just recently released. PRM is actually now a subdomain of the BRIDG model. PRIDG stands for Biomedical Research Integrated Domain Group and is a collaborative effort engaging stakeholders from the Clinical Data Interchange Standards Consortium (CDISC), the HL7 Regulated Clinical Research Information Management Technical Committee (RCRIM TC), the National Cancer Institute (NCI) and its Cancer Biomedical Informatics Grid (caBIG®), and the US Food and Drug Administration (FDA).

For each clinical trial, the study protocol is the key. The study protocol is typically a text document and is developed from the protocol template. The protocol is considered as a document, not a data. PRM is trying to change this.

The PRM is NOT a specific protocol template; rather, when a template is designed to meet the purposes of a given organization or study type, the use of the PRM common elements will enable and facilitate information re-use without constraining the design of the study or the style of the document. The PRM elements have been found to be typical across study protocols, but they do not reflect either a minimum or a maximum set of elements.

There are four major components of the PRM v1.0—that is, four major areas of a protocol that the elements are related to:

  • Clinical Trial/Study Registry: Elements related to the background information of a study, based on the requirements from WHO and Examples of elements in this area include Study Type, Registration ID, Sponsors, and Date of First Enrollment.
  • Eligibility: Elements related to eligibility criteria such as minimum age, maximum age, and subject ethnicity.
  • Study Design Part 1: Elements related to a study’s experimental design, such as Arms and Epochs.
  • Study Design Part 2: Elements related to a study’s Schedule of Events and Activities.
It is envisioned that with PRM, the key elements of the protocol can be considered as data strings and can be stored in the data set and can be re-used. The statistical analysis plan can be easily developed by importing the key elements from the protocol. However, to make all companies to follow this standard will take time. There may be a lot of challenges in implementing this standard. This standard needs to be endorsed by the medical writers and medical directors (not the data managers and statisticians) who actually develop the study protocol.

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