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Common Data Element (CDE) Resource Portal


The CDE Resource Portal includes four types of CDE Resources, grouped by their characteristics. Resources include lists of CDEs, surveys, questionnaires, instruments, instrument items, and other methods of data collection.

  1. NIH CDE Initiatives  Summary table  Subject areas  Resource summaries
    • Collections of CDEs that have been identified for use in particular NIH-supported research projects or registries.
    • These typically result from formal processes to identify, evaluate, and select data elements for inclusion; constraining the choice of data element to be used for a particular concept.
    • They may identify a minimum or core set of data elements to be collected in all studies or registries of a particular type (e.g., genome-wide association studies, studies of neurological disease, rare disease registry).
    • These resources are free to use although may require registration for access.
  2. CDE Tools and Resources  Summary table  Subject areas  Resource summaries
    • Databases and repositories of data elements and case report forms.
    • These may contain tools to assist investigators in selecting data elements that are relevant to their research or registry.
    • While not limiting options for data elements to be used in particular research projects (as in NIH CDE Initiatives above), they promote standardization and commonality by facilitating the reuse of existing data elements.
  3. Other CDE Resources  Resource summaries
    • Other collections of CDEs that have been developed or identified with lesser involvement from NIH, but have potential for use in biomedical research.
    • May require a fee for use.
  4. Relevant Standards  Resource summaries
    • Clinical vocabularies, terminologies, and standards that can improve the comparability of data collected in clinical research and/or with patient data in electronic health records.
    • These standards are used in EHRs that are certified to meet meaningful use criteria.



The terms data element and common data element have been used in many ways. Here, these and related terms are defined for the purposes of the CDE Resource Portal.

  • Common Data Element (CDE) - A data element that is common to multiple data sets across different studies. Commonality may be intentional or unintentional; this Portal places emphasis on the intentional use of CDEs to improve data quality and promote data sharing. Certain types of CDEs are sometimes described:
    • Universal - CDEs that may be used in studies, regardless of the specific disease or condition of interest, e.g., demographic information of study subjects, medical history, certain patient-reported outcomes.
    • Domain-specific - CDEs that are designed and intended for use in studies of a particular topic, disease or condition, body system, or other classification, e.g., Parkinson's disease, Alzheimer's disease, diabetes, ophthalmology. Some domains are broadly applicable to a wide range of studies, while others are more useful in specific fields of clinical research.
    • Required - CDEs that are required or expected, as a matter of institutional policy (e.g., research funder or performer), to be collected for all subjects in studies of a particular type, e.g., NIH-funded studies of neurological disease, or NIH-funded studies of the genetics of eye disease.
    • Core - CDEs that are required or expected to be collected in particular classes of studies, e.g., any study of neurological disease or cancer, any genome-wide association study. Other, domain-specific common data elements may be suggested, expected, or required for collection, depending on the more specific focus of the study (e.g., Alzheimer's disease, ovarian cancer, genome-wide association study of diabetes).
  • Data Element (DE) - Information that describes a piece of data to be collected in a study. The DE does not include the data themselves. Three examples of DEs are provided below. Attributes of DEs often include:
    • Name - The name of the DE. A short version of the name or a code may be used in addition to the name.
    • Definition - An explanation of the nature, scope, or meaning of the DE.
    • Query/Instructions - Additional details about the DE beyond the definition. This may include instructions to the patient on how to respond to a question, instructions on how to conduct a laboratory test, etc.
    • Provenance - Information describing the history or origin of a DE, as well as its scientific validity. This can include references to journal articles, Vocabularies or Data Standards, review process, validation, owner or creator, or other information.
    • Value Set - The set of possible values or responses. A Value Set often includes concepts from established Vocabularies or Data Standards. For laboratory tests, a value set may include a range of permissible values and indicate the required units. For a survey question, the value set may be a list of possible responses.
  • Related Terms
    • Data Standard - Agreed upon set of rules that allow information to be shared and processed in a uniform and consistent manner. This includes representations, formats, and definitions of data. Some CDEs have been mapped to existing data standards and vocabularies such as those listed in the Health Information Technology and Health Data Standards at NLM.
    • Vocabulary - A database of concepts with their corresponding definitions and codes that may include relationships between concepts.


Name of Common Data ElementDefinitionQuery / InstructionsProvenanceValue SetResource
FOLLOWUP_SMOKE_-HX_ AVERAGE-DAY_VALUE Average number of cigarettes participant smokes per day Average number cigarettes currently smoked per day? (How many cigarettes do you currently smoke per day?) Record the average number of cigarettes participant currently smokes per day. This question is only asked if a positive response was received for FOLLOWUP_SMOKE-HX_CURRENT-REGULAR_CODE. Not indicated. Integer between 1 and 999, no unit. EDRN
Societal Sex (phenotype) Text designations that identify gender. Gender is described as the assemblage of properties that distinguish people on the basis of their societal roles. Self-identified gender. This value set is from Health Level Seven International (HL7) Table 0001 (with additions). HL7 is the global authority on standards for interoperability of health information technology. Ambiguous; Female; Male; Not applicable; Other; Unknown; Male-to-female transsexual; Female-to-male transsexual GRDR
Lab test name Identifier name given to a test performed on body fluid(s) and tissues. Test names are typically comprised of the analyte name, properties (%, Ratio, etc.), the type of body fluid tested, and any special instructions. Indicate the name of each laboratory test that is run on the specimen. Values are a subset of the Logical Observation Identifiers Names and Codes (LOINC) vocabulary; NCI CDE Browser Public ID = 2003746 Urea; Creatinine; Aspartate Aminotransferase (ASAT/SGOT); Alanine Aminotransferase (ALAT/SGPT); Total Bilirubin; Sodium; Potassium; Hemoglobin; Hematocrit; Neutrophils; Lymphocytes; Eosinophils; Platelet; Other, specify NINDS CDEs


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