Define-XML is a machine-readable metadata document that explains the content of submitted study datasets. It describes, among other things, datasets, variables, controlled terminology, origin, and derivations so that a reviewer can understand the structure and meaning of SDTM or ADaM data. The document does not carry the table values themselves but provides the key to their interpretation.<\/p>\n
A tabular dataset without additional explanation often contains only variable names, values, and technical types. Define-XML supplements this with dataset labels, variable labels, data types, permissible value ranges, and controlled terminology systems. For derived analysis variables, it can also describe the derivation and the input data used. This makes it clear how a result dataset should be read from a subject-matter perspective.<\/p>\n
The metadata must match the actual data deliverable. A variable described in Define-XML as a required variable but named differently or missing in the ADaM package immediately complicates review. Precise references are particularly important for controlled terminology and value lists because they explain why a specific value is permissible and which coding was expected.<\/p>\n
The FDA requires a Data Definition File for standardized study data and describes Define-XML as the format for complete metadata of submitted SDTM, SEND, and ADaM datasets. The Study Data Technical Conformance Guide links the data definition to Reviewer Guides and traceability between tabulation, analysis, and results. A Define-XML does not replace these explanatory documents but complements them at a machine-readable level.<\/p>\n
The CDISC page for Define-XML v2.1 lists package update v2.1.11 dated April 6, 2026. The update concerns the schema file for enumerations related to Controlled Terminology Package 61. Which version is actually to be used for a submission depends on the respective regulatory requirements and the applicable Data Standards Catalog.<\/p>\n
SDTM organizes clinical tabulation data, while ADaM supports analysis-ready data and associated traceability. Define-XML describes these data holdings and their elements so that a reviewer can understand their structure. Without such a metadata description, even technically correctly delivered SDTM and ADaM files remain open to interpretation in important respects.<\/p>\n
Operational Data Model serves as a vendor-neutral exchange and archiving format for data together with metadata and other information. Define-XML is a specialized metadata description within the CDISC environment and is not a replacement for the operational transfer of an eCRF design between systems. The two standards may share technical building blocks but address different tasks.<\/p>\n
For datasets from a controlled programming pipeline, Define-XML is also a handover point between subject-matter specification and technical delivery. The data definition should not be generated only from the final XPT or JSON files but should be based on released metadata. Otherwise, program names, analysis plan, and definition can diverge\u2014for example, if a subgroup variable is renamed or a codelist is extended. Reusable metadata libraries facilitate consistency but do not exempt from study-specific review.<\/p>\n
For ADaM, the explanation of origin is particularly central because values may be derived from multiple SDTM variables, imputed, or composed into analysis time points. The metadata should not force a reviewer to search program code to understand the purpose of a variable. They also do not create subject-matter justification for a derivation; this must emerge from the analysis plan and associated specifications.<\/p>\n
When the dataset structure changes, it must therefore be checked at the same time whether the definition, the associated Reviewer Guide, and the conformance check reflect the same version of the data model.<\/p>\n
This protects the machine-readable deliverable from unnoticed semantic drift.<\/p>\n
Work on Define-XML does not begin only at database lock. Variable origin, codelists, and derivations should already be unambiguous in SDTM and ADaM specifications so that metadata do not later have to be inferred from program code. Changes to terminology or to analysis derivations must be updated simultaneously in the data and in Define-XML. Discrepancies often emerge only during conformance checks or in review preparation.<\/p>\n
Full-service CROs such as Mediconomics support the creation and quality control of Define-XML, the maintenance of controlled-terminology metadata, and coordination with SDTM and ADaM programming. Biostatistics, data management, and medical writing can thus prepare variable-level metadata, Reviewer Guides, and traceability of key derivations consistently for a submission.<\/p>\n
Does Define-XML contain the patient data of a study?<\/strong><\/p>\n No. Define-XML describes datasets and variables. The actual observations and analysis values reside in the associated data holdings.<\/p>\n Why does ADaM require a metadata description?<\/strong><\/p>\n ADaM may contain derived or imputed analysis values. The metadata show which variables are present, how they are described, and on what their derivation is based.<\/p>\n Is every latest Define-XML version automatically suitable for FDA submission?<\/strong><\/p>\n No. The current CDISC release and the versions supported by the FDA for the specific submission time point must be checked separately.<\/p>\n Define-XML is a machine-readable metadata document that explains the content of submitted study datasets. It describes, among other things, datasets, variables, controlled terminology, origin, and derivations so that a reviewer can understand the structure and meaning of SDTM or ADaM data. The document does not carry the table values themselves but provides the key to […]<\/p>\n","protected":false},"author":10,"featured_media":0,"parent":0,"template":"","meta":{"_acf_changed":false,"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"glossary-cat":[25],"class_list":["post-8055","glossary","type-glossary","status-publish","hentry","glossary-cat-datenmanagement-eclinical"],"acf":[],"related_terms":"","external_url":"","internal_reference_id":"","_links":{"self":[{"href":"https:\/\/mediconomics.com\/en\/wp-json\/wp\/v2\/glossary\/8055","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mediconomics.com\/en\/wp-json\/wp\/v2\/glossary"}],"about":[{"href":"https:\/\/mediconomics.com\/en\/wp-json\/wp\/v2\/types\/glossary"}],"author":[{"embeddable":true,"href":"https:\/\/mediconomics.com\/en\/wp-json\/wp\/v2\/users\/10"}],"version-history":[{"count":0,"href":"https:\/\/mediconomics.com\/en\/wp-json\/wp\/v2\/glossary\/8055\/revisions"}],"wp:attachment":[{"href":"https:\/\/mediconomics.com\/en\/wp-json\/wp\/v2\/media?parent=8055"}],"wp:term":[{"taxonomy":"glossary-cat","embeddable":true,"href":"https:\/\/mediconomics.com\/en\/wp-json\/wp\/v2\/glossary-cat?post=8055"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Regulatory References<\/h2>\n
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