MSDUR is no longer listed in the MS specification

Rule

VAR-025

Category

Variables demoted

Basis

Draft Read from the public-review draft. The draft can still change before v4.0 is final, and this rule changes with it.

Detectability

External context required The Define-XML cannot settle this. Answering it needs a decision or a fact held outside the submission metadata.

Finding type

Question

Applies to

SDTMIG 3.2, 3.3, 3.4

What changes in v4.0

MSDUR (Duration) is present in the v3.4 Microbiology Susceptibility specification table and absent from the v4.0 one. --DUR itself is unaffected and appears in thirteen v4.0 domains. Section 4.2.4 states that the specification tables list only some of the available variables and that all remain permissible unless a usage restriction or domain assumption prohibits them. The MS assumption is unusually short and points the other way: it permits timing variables generally — "any identifiers, timing variables, or Findings general observation class qualifiers may be added to the MS domain" — and names only --TOX, --TOXGR and --SEV as variables that "would not generally be used". --DUR is a timing variable, so it falls inside a category the assumption permits and is not one of the three stated exceptions. That is general permission for the category plus absence from the exclusion list, which is weaker than a statement about MSDUR itself; nothing in the draft names MSDUR at all.

What to do about it

Choose deliberately: keep MSDUR, which the MS assumption does not list as an exception to its general permission for timing variables, or derive duration downstream from the surviving start and end timing variables. Both are available and v4.0 does not prefer one. Record which you chose and why.

What the scan can and cannot see

MSDUR being declared is conclusive; whether it may stay is not. The MS assumption permits timing variables generally and names only --TOX, --TOXGR and --SEV as exceptions, nothing in the draft names MSDUR at all, and no source explains the table change.