Epoch is a permissible variable in CDISC, but it’s also a variable requested by FDA in CDER Common Data Issues document and should be included in the dataset for these domains:
| Events | AE |
|---|---|
| Events | CE |
| Events | DS |
| Events | DV |
| Events | EVENTS |
| Events | MH |
| Findings | DA |
| Findings | EG |
| Findings | FA |
| Findings | FINDINGS |
| Findings | LB |
| Findings | MS |
| Findings | PC |
| Findings | PE |
| Findings | PP |
| Findings | QS |
| Findings | RS |
| Findings | TR |
| Findings | TU |
| Findings | VS |
| Interventions | CM |
| Interventions | EX |
| Interventions | INTERVENTIONS |
| Interventions | SU |
Thank you @mdigian for your response!
This is an example of the very bad practice that a stakeholder is changing the standard after its publication, where it had the opportunity to request for the incorporation of the variable during the review period. How can we trust standards when a stakeholder deviates from it and creates its own “dialect”?
Thanks, helpful answer, and something that’s not easy to discover from the FDA website! Downloaded OpenCDISC just a couple of days ago and already it’s proving very helpful!
This was published in December 2011 by the FDA, a major stakeholder of the standards.
SDTM 3.1.3 was published after this guidance. Do you know if CDISC simply chose not to change EPOCH’s core value from Perm to Req for certain domains ?
Hi,
Anyone know where the EPOCH variable should go in the table? At the end? After all the --DTC/–DY variables? Anywhere?
Thanks,
Rosie
Hi Rosie,
A position of any variable including EPOCH is defined by SDTM Model.
E.g., for SDTM v1.4 see a Table 2.2.5 (Timing VAriables for All Classes) on page 19:
VISITNUM
VISIT
VISITDY
TAETORD
EPOCH
–DTC
–STDTC
–ENDTC
–DY
…
EPOCH should be just before --DTC, --STDTC variables.
Kind Regards,
Sergiy
Thanks, Sergiy! I was using the SDTM IG and forgot about the SDTM doc. Really don’t understand why they publish them as separate docs…
Hi @mdigian ,
I don’t understand why MH also need an EPOCH variable? All MH records are supposed to be collected during screening phase.
Think of the SDTM 1.x as the generic model for the 3 general observation classes: FINDINGS, INTERVENTIONS, EVENTS. It defines the blue print and superset of variables available for those classes. The order of variables is a general starting point.
The IG then inherits and implements a generic class as a domain while supplying domain specific semantics (controlled terminology assignments, assumptions, prohibiting use of some variables). In some cases, the domain will override the variable order. in the case where a variable is not mentioned and not prohibted, its order is inherited from the parent class.
This is why they publish two separate docs. Base Parent (Model) and IG (instance of model).
SDTM 1.x is implemented by the following:
Hi mdigian,
I don’t understand why MH also need an EPOCH variable? All MH records are supposed to be collected during screening phase. Thanks!
Hi mdigian,
I don’t understand why MH also need an EPOCH variable? All MH records are supposed to be collected during screening phase. Thanks!
Short answer, FDA requires it in their Tech Conformance Guide: http://www.fda.gov/downloads/ForIndustry/DataStandards/StudyDataStandards/UCM384744.pdf
“..variable EPOCH should be included for every clinical subject-level observation … This will allow the reviewer to easily determine during which phase of the trial the observation occurred as well as actual intervention the subject experienced during that phase”
My take / long answer…
while MH is “supposed” to be collected during screening phase, perhaps a use case will develop where it is collected throughout the study. Perhaps for early stage alzheimer’s. The other use case is if some database warehouse or tool wants to stack all EVENTS observations into one table. Having EPOCH populated for medical history will allow a consistentency in the combined view. Finally, at any point during a study (especially for pediatric studies) it’s possible someone could simply offer up more medical history than what they previously recalled. Or a parent/guardian recalls something signficant about their child in a study which was not previously recorded.
Bottom line, from a tech perspective (mapping), it’s easy just to hardcode this variable to SCREENING if that is your case and move on to more challenging endeavors.
Take care,
Mike.
Thanks so much, it is very helpful.
Hi,
How would you populate the EPOCH variable in the CM domain in the event that dates are partially known? Does one needs to impute dates in order to determine the EPOCH?
What if the CM dates indicates that the medication was taken long before the study screening period? for example few years before the study ever conducted, will it be accurate to mention the EPOCH as screening period?
Thanks,
Liron
partial dates: do NOT impute EPOCH (imputations are not allowed in SDTM).
medication taken long time before study start:
EPOCH is an extensible codelist. So you can add your own terms. For example, you could add “PRESCREENING” to the codelist in the define.xml (do not forget to add the attribute def:ExtendedValue=“Yes”) to the “CodeListItem” or “EnumeratedItem” element, and use that for all dates (also partial ones) that are clearly before the study start date. For example “2015-01” is clearly before the study start date “2015-02-01”.
As explained in Working on and with CDISC Standards: EPOCH expected in most SDTM domains - why that is nonsense this is a ridiculous requirement of the FDA, as EPOCH can easily be automatically be derived and added as tooltip or column by the tools that the FDA is (or should be) using. It took me less than 2 hours to do so in my visualization tool.
Thank you
Long comment to an old post dropped (belatedly saw dates)
A few comments:
Here is a 1:1 copy of what is in the latest “Study Data Technical Conformance Guide” (October 2015):
“Please include the variables EPOCH for every clinical subject-level observation (e.g., adverse events, laboratory, concomitant medications, exposure, vital signs). This will allow the reviewer to easily determine during which phase of the trial the observation occurred (e.g., screening, on-therapy, follow-up), as well as actual intervention the subject experienced during that phase.. Inclusion of ELEMENT and ETCD (element code) is desired as well, to help reviewers understand timing of events whose durations span multiple epochs. However, because of implementation challenges associated with this request, CDER is not yet requiring these for submission of SDTM data”. (see http://www.fda.gov/downloads/ForIndustry/DataStandards/StudyDataStandards/UCM384744.pdf).
So the previous statement of one of the contributors “… it’s also a variable requested by FDA in CDER Common Data Issues document and should be included in the dataset for these domains” looks like a complete overinterpretation of the FDA’s position.
“Please include …” does not sound like an obligation to me, and “e.g. adverse events …” does not sound like a complete list (MH is even missing in that list). So I think this rule should either disappear or be downgraded to “INFO”.
BTW, reviewers should be able to derive EPOCH themselves - it is really piece of cake to do so.
Best regards,
Jozef