FDA’s June 2026 conformance guide treats USUBJID as the unique subject identifier intended to support consistent subject identification across studies involving the product.
ReviewedEvidence1 sourceSectionWriting & Style
Quick answer
Construct USUBJID so that the subject identifier remains unique across the studies/applications covered by current FDA study-data guidance.
Key details
Core IssueFDA’s June 2026 conformance guide treats USUBJID as the unique subject identifier intended to support consistent subject identification across studies involving the product.
Registerscholarly, professional, or research/report writing
Important caveats
Scope Boundary
This is current FDA technical-conformance guidance for electronic study-data submissions; recheck the current FDA guide, supported standards, and eCTD specifications before relying on version-sensitive requirements.
Further guidance
Content
Do not collapse USUBJID into the study-level SUBJID field; their scopes differ.
Purpose
Construct USUBJID so that the subject identifier remains unique across the studies/applications covered by current FDA study-data guidance.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
FDA’s June 2026 conformance guide notes that there is no single standard or best practice for all adjudication data and directs sponsors to document where adjudication data reside and how adjudicated values can be distinguished from original values.
FDA’s June 2026 guide says the AE domain should include all adverse events unless an indication-specific technical specification says otherwise and asks for the criterion supporting a serious-event flag.
In the June 2026 FDA Study Data Technical Conformance Guide, ASOCSTDY is the Trial Summary parameter code for Associated Study; FDA lists it as conditional for nonclinical Trial Summary data. FDA notes: include it if applicable. This is FDA submission guidance, not a universal SEND rule detached from the current FDA-supported standards and conformance guide.
FDA’s June 2026 guide separates categorical noncontinuous laboratory results from numeric continuous results by using LBSTRESC, leaving LBSTRESN null, and documenting the categorical scale in the nSDRG.
FDA’s June 2026 conformance guide says a custom domain should be used only after confirming the data do not fit an existing domain, with implementation described in the clinical Study Data Reviewer’s Guide.
FDA’s June 2026 conformance guide recommends sizing character-data columns to the maximum variable length used across study datasets, with a separate individual-dataset rule for SUPPQUAL datasets. This is current FDA technical-conformance guidance for study-data files; exact implementation must still follow the applicable supported data standard and submission format.
FDA’s June 2026 guide describes the DD (Death Details) domain for supplemental information collected when a death occurs and expects consistency with relevant AE-domain death variables.
FDA’s June 2026 conformance guide says screen failures, when provided, should be represented as a DM record with specified planned/actual arm fields left blank.
