CMENRTPT vs CMENRF in SDTM
Understanding CMENRTPT vs CMENRF in SDTM
By Sarath
Introduction
When working with the Concomitant Medication (CM) domain in SDTM, it's crucial to understand how timing variables like
CMENRTPT (End Relative to Reference Time Point) and CMENRF (End Relative to Reference Period) differ and when to use each.
What is CMENRTPT?
CMENRTPT indicates the relationship between the end of the medication and a specific time point, such as the start of treatment or a significant event (e.g., surgery).
- Controlled Terminology: BEFORE, AFTER, ONGOING, CONCURRENT
- Example: If a medication was stopped before surgery,
CMENRTPT = "BEFORE".
What is CMENRF?
CMENRF describes whether the medication ended before, during, or after a specific study period, such as Screening, Treatment, or Follow-up.
- Controlled Terminology: BEFORE, DURING, AFTER
- Example: If a medication ended during the treatment phase,
CMENRF = "DURING".
Key Differences
| Aspect | CMENRTPT | CMENRF |
|---|---|---|
| Focus | Relationship to a specific time point | Relationship to a study period |
| Granularity | More precise | Broader |
| Typical Use Case | Linking to an event like surgery | Contextualizing within a study phase |
Example Scenario
Scenario: A medication was stopped two days after surgery, which occurred during the screening phase.
- CMENRTPT: AFTER (relative to surgery)
- CMENRF: BEFORE (relative to the start of the treatment phase)
Conclusion
By understanding the differences between CMENRTPT and CMENRF, clinical programmers can ensure accurate and standardized representation of concomitant medication timing in SDTM datasets. Always refer to the study protocol and CDISC standards to select the appropriate variable for your data.