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How would you map a specific concept (Prostate Specific Antigen Follow up)?

Hello everyone!
I’m currently working in the development of my first CDM and I have come across with a concept that I don’t know what concept i need to use and in which table i should map it to. The concept is “prostate specific antigen follow up with early salvage radiation therapy”. My idea would be to break this concept into two parts, one for the prostate specific antigen follow up measurement and one for the procedure of early salvage radiotherapy.

  1. Is this idea correct? If not, what would you suggest?
  2. How would you specify the “follow up” information in the CDM?
  3. How would you specify the extra information of “early salvage” in the radiotharapy?

Hope i explained my problem correctly :slight_smile:

Hi @manoshatzak:

Looks good.

Forget the “follow-up”. That is a reference to an earlier measurement or intervention (probably surgery). If you have those in your data the fact that it is a follow-up is self-evident. If not, a blind reference to something undefined earlier is not useful for analytics.

Same logic. The “salvage” means that the original treatment wasn’t working, and now another treatment is conducted. “Early salvage” means the intervention (often radiotherapy) happened “early” after the initial treatment (usually surgery), i.e. before the cancer had time to grow back much. Only the PSA measurement indicates that the tumor is still there. Again, just record the treatment and time.

Many prostate cancers (which this is all about) are going through the strategic and difficult decision of either immediate treatment or waiting and seeing whether the cancer is aggressive. This is because it often grows so slowly that the older gentlemen will die of other causes before the cancer bothers him, and a treatment would be an unnecessary hassle. So, both terms refer to a sequential strategy that the provider has in mind. Longitudinal data don’t care about strategy or intent, only about what happened. And only what happened at the time stamp.

Thank you very much for your help!!