Ankle brachial pressure index

We’re looking for an “ankle brachial pressure index” archetype.
We did not find anything in CKM. But we did find such an archetype in norwegian ckm by @siljelb.

I wondered why the pressure measurements are part of the archetype. In my opinion the brachial pressure would best be recorded as observation.blood_pressure. And the ankle pressure as OBSERVATION.intravascular_pressure (since it’s not a surrogate for the systemic arterial pressure). Similar to BMI.
I would be interested to discuss adding references to the values used to the observation.ankle brachial index archetype, probably as DV_EHR_URI, under the protocol section?

Thoughts?

Hi Joost! This archetype was imported based on this proposal back in 2017, and has been sitting there untouched since then.

I don’t have any strong feelings about the modelling pattern, other than the fact that both the upper arm and the ankle are measurement locations included in the OBSERVATION.blood_pressure archetype, and should therefore both be possible locations to measure a surrogate for the systemic arterial pressure? I’m not sure what the difference is between an ankle systolic blood pressure which is measured as a surrogate for the systemic arterial pressure, and one which isn’t?

Yeah, I saw the obs.bloodpressure has an ankle measurement location.
The (main?) indication for taking a ‘ankle brachial pressure index’ is suspected low (regional) blood pressure in the foot, as part of suspected peripheral arterial disease. So the ankle pressure has a high chance of not adequately reflecting the systemic blood pressure when taken as part of a ankle brachial index.
If we agree on this, maybe we should add a comment to the obs.bloodpressure. (if even one of the most experienced modellers doesn’t think of this, we can’t assume regular modellers do.)

I agree. Though also perfectly valid to use the ankle pressure as a systemic pressure (assuming we are confident that it is not compromised by peripheral; disease).

I bet the banks don’t have to think of this sort of thing!!

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