Website Edition: December 2010/January 2011
Related article: It's Elementary - Collecting Data That Unite Research Efforts

Invitation for Review and Comment

The National Institute of Neurological Disorders and Stroke Announces Public Comment Period for Parkinson's Disease Common Data Elements (CDEs)

Parkinson's Disease
CDE Working Group

Chairs: Karl Kieburtz, MD, MPH and Caroline Tanner, MD, PhD

View Working Group members

By Wendy R. Galpern, MD, PhD
Program Director, Clinical Trials

The National Institute of Neurological Disorders and Stroke (NINDS), part of the National Institutes of Health (NIH), recently assembled an external working group of nearly 70 international experts to develop the Parkinson's Disease Common Data Elements (PD CDEs). This group of clinicians and researchers developed a series of recommendations for data collection across clinical research studies in PD, and the CDEs are now available for feedback from the larger PD clinical research community. The NINDS invites you to provide feedback on the recommendations which can be accessed via the following link: The PD CDEs will be available for public comment until Friday, December 31, 2010, and it is anticipated the PD CDEs will be available for public use in early 2011.

NINDS Common Data ElementsWhat is the NINDS Common Data Elements Project?

The NINDS initiated the Common Data Elements (CDE) Project in an effort to facilitate clinical research across a variety of neurological disorders including PD. The NINDS CDE Project has already developed General CDEs that are typically collected in clinical studies regardless of therapeutic area, such as demographic information, as well as CDEs for traumatic brain injury, epilepsy, and spinal cord injury; all are available for use on the NINDS CDE Website ( Efforts also are underway to develop CDEs for several other neurological disorders including Friedreich's ataxia and Huntington's disease as well as frontotemporal dementia, stroke, headache, multiple sclerosis and neuromuscular disorders, including ALS.

By identifying CDEs in a standardized format, and by developing common documentation and case report forms, the NINDS hopes to facilitate the development of data collection tools, reduce study start-up time, promote systematic data collection, improve data quality, and facilitate the comparison of data among studies.

For PD, the following topic-specific subgroups were formed:

General and Motor

Functional Neurosurgery
Other Non-Motor
Quality of Life


In addition, a Statistics and Scale Metrics subgroup as well as an Operations subgroup served in an advisory capacity.

What is a Common Data Element?

A CDE is a logical unit of data pertaining to one kind of information. Each element has a name, a precise definition, and a clear enumerated value. For example, an element name might be "Year of initial diagnosis", the definition "Year physician first diagnosed PD", and the code value a 4-digit numeric "YYYY". As shown in the figure below, CDEs are classified according to the studies in which they will be included.

CDE figure

What are the Parkinson's disease CDE Products?

Each Subgroup identified data elements commonly utilized in PD clinical studies in order to standardize the collection of the most relevant and useful data. While the CDEs do not define the complete universe of variables, they aim to define elements that will be useful across most PD studies. The products include:

  • A catalog of approximately 600 PD CDEs with detailed specifications for each CDE
    • Template Case Report Forms
    • Data dictionaries
  • A list of approximately 70 standardized instruments with explanations regarding recommended use (e.g., screening, rating, diagnosis)
  • Additional documentation including summary tables and guidelines for use

Next steps

The NINDS invites you to review the PD CDEs and provide feedback by Friday, December 31, 2010. Once posted for use, NINDS hopes the PD research community will utilize these tools when planning future studies.

The PD CDE Project is dynamic, and the development process is iterative. In order to ensure that the PD CDEs are useful tools for the research community, there will be an ongoing collection of feedback. This information will be incorporated in order to keep the CDEs current.

Investigators conducting clinical research studies are encouraged to use the CDEs and submit feedback through the CDE website: