Cohort Pathways in Atlas - FAQ

[Akshay (Akshay Kumar)]

@Chris_Knoll

With 0 days of lookback, how can you determine if this is a new case of T2DM? The reason why it’s an important question is that if you’re going to evaluate a patient’s journey through T2DM treatments, do you want to start watchign them in the middle of their journey, or do you want to ensure that they have just begun? You need prior lookback to determine that.

Hi @Chris_Knoll - When I set a lookback period of 0 days and set it to earliest event, I will get his first time diagnosis for T2DM. Am I right here? Because since it’s 0 days of lookback, it will return all occurrence of T2DM dx codes from his data and when I pick the earliest, it gives us the first time he was diagnosed for T2DM and what was the treatment pathway initiated for his 1st T2DM. Isn’t this similar to finding persons who have just been diagnosed for T2DM?

@Chris_Knoll

Do you only want to find events while the person is on an active treatment? Do you want to look for events any time after that first diagnosis?

As I am interested to find his medication treatment sequence, Under target cohort I believe I have to go for “end of continuous observation”. So that I can get all his drug sequence data whereas if I go for “end of continuous drug exposure”, that may not allow me to look at other drugs (except the one configured under exit criteria). Am I right? In latter case, I will not be able to find info on his other treatments.

Under “event cohorts”, since I would have selected a drug exposure of “DRUG A” in cohort entry criteria, now if I set “end of continuous observation”, it would still only consider “Drug A”'s presence in target cohort. Am I right?

I see that in your response here, you have chosen “fixed duration relative to initial event” with an offset of 1 day from start date.

Since in the event cohort definition, we have chosen “DRUG A” in the cohort entry criteria with 0 lookback, so it returns earliest event based on your setting. It returns 1st occurrence of “Drug A”. Since we already got to know that it is present in the event cohort, so you exit the cohort after 1 day itself? May I know the reason or it was just a quick example ? But if we do this aren’t we losing subsequent records which can prevent us from finding combination therapy items?

@Chris_Knoll

f you have two different event dates that are fewer days than the combination window setting, those 2 dates will be brought together (hence the term ‘combined’) into a single date (the earlier of the two)

Let’s consider the below treatment sequence for a subject. tried to create it based on your pdf shared

Here for this subject, we know his 1st drug treatment is “DRUG A”. period

Next if I am gonna look at combination therapy and I set the window to be “5 DAYS”, then it’s “DRUG A, DRUG B and DRUG C” which are under combination therapy. Am I right?

If I set “2 DAYS” as combination window, then all 4 drugs would be under combination therapy. Am I right?

I did have a look at the pdf file that you shared.

Now based on your explanation of

@Chris_Knoll

If you have two different event dates that are fewer days than the combination window setting, those 2 dates will be brought together (hence the term ‘combined’) into a single date (the earlier of the two).

By event date, for our usecase of treatment pathways (finding drug treatment sequence) it can only be drug exposure start date? Am I right?

Here event date for DRUG A - Jan 1st
event date for DRUG B - Jan 3rd
event date for DRUG C - Jan 2nd
event date for DRUG D - Jan 9th.

Now if our combination window is set to “5 days”, then I will still get DRUG A, DRUG B, DRUG C to be part of combination therapy. Am I right? So basically, if the difference between 2 event dates (drug A start date and drug B start date) is less than the combination window (5 days), then it will be considered as combination therapy?

Can help me with this please?