I am currently modelling occupational, sports and traffic medicine templates and have encountered the need to record multiple skinfold measurements as part of anthropometric assessment.
Examples include:
Triceps skinfold
Biceps skinfold
Subscapular (back) skinfold
Forearm skinfold
Abdominal skinfold
Chest skinfold
Suprailiac skinfold
Thigh skinfold
Calf skinfold
I initially reviewed the Body segment length archetype, but it explicitly states that it should not be used for skinfold measurements. However, I was not able to find a dedicated skinfold measurement archetype in CKM.
Based on discussion with colleagues, a potential approach would be (following similar logic as Body segment length archetype) to create a generic OBSERVATION.skinfold_measurement archetype with the following data elements:
Body segment / Test name with value set for the different skinfold sites
Measurement (mm)
Optional laterality
Optional structured anatomical location
*State and Protocol similar to Anthropometry project archetypes
Before creating a local archetype, I wanted to ask:
Does such an archetype already exist in development?
Would the community prefer a single generic archetype, or separate archetypes per anatomical site (similar to waist circumference)?
Would there be interest in contributing this as an international anthropometry archetype?
I would also appreciate any feedback on whether additional data elements would be suitable to include in the custom archetype described above.
This seems broadly applicable across occupational medicine, sports medicine, nutrition, and research contexts.
I think you are well on track. Well done for all your detective work.
Yes, we anticipated that a dedicated skinfold archetype was required but not in scope for the other anthropometric work being carried out at the time. I am not aware of anyone else working on this. Here is our opportunity! I would encourage you to develop it so that it can be added to the international archetype library.
There are a few other specific circumference-related archetypes. This is an intentional design approach as they are used commonly and explicitly for other purposes than ‘body segment’ measurements and may need specific protocol and events. Examples are head circumference or waist.
However, I would keep the current body segment family of archetypes closely in mind as we design this one.
In my noodling around the common skinfold thicknesses measured are close to yours:
Triceps
Biceps
Subscapular
Suprailiac
Iliac crest
Supraspinale
Abdominal
Mid-axillary
Pectoral
Front thigh
Medial calf
Many are identical, some are a little more specific, some a little more generic. The only one that didn’t come up for me was the Forearm so I am a little curious about your use case. Ultimately the list of body sites that we add to the archetype need to be as standardised as possible, always mindful that we can add other sites over time. You will also note that data type for the list of measurement types in the body segment archetypes is a choice of DV_TEXT and DV_CODED_TEXT so we can add the standard body sites for skinfold thicknesses but also allow others to be included in a template if necessary.
I think that this archetype is a little more specific than the body segment ones, such that the index data element that needs to be mandatory is really the ‘Body site’ for the thickness measurement and the value set similar to above.
Then Thickness measurement, Laterality, just as you propose. The idea of adding a SLOT for a structured ‘Body site’ is interesting to consider, including the ability to have a relative anatomical location.
Thank you for the helpful feedback and encouragement.
It’s good to know that a dedicated skinfold thickness archetype was anticipated but not yet developed. I will proceed with drafting one, keeping the current body segment family of archetypes in mind as suggested.
I agree that the key mandatory element should be the Body site, with a standardized list of common skinfold sites and flexibility to include others where needed. Regarding the forearm skinfold, this came from requirements related to body skinfold measurements in sports medicine for athletes, but I will review the list again to ensure it aligns well with common standards.
I’ll prepare a refined draft and would be very glad to share it with you for further input.
In my opinion the archetype looks like a good initial proposal, and should not need significant work before it can be reviewed.
I have a couple of minor comments:
Should the “Thickness” measurement also be mandatory, since it’s the only measurement result element?
Should the same “Thickness” element have a higher maximum value than 100 mm? That seems conservative to me as an absolute technical limit. Bear in mind that for example the Blood pressure archetype has a maximum value of <1000 mmHg.
For the “Laterality” element, does the “bilateral” option make sense? I have trouble envisioning how a single measurement could measure a skin fold on both sides of the body?
Thank you for the thoughtful feedback - all three points are well taken.
Agreed - I’ll make “Thickness” mandatory. The body site and the thickness are both equally essential for the record to be meaningful.
Another great point - helps to put the bound into perspective when compared to other observation archetypes and the 100 mm upper bound was overly conservative. I’m guessing a 1000 mm upper bound would make more sense or even completely removing the magnitude constrain? What would you suggest?
I guess “Bilateral” would only make sense if both sides are recorded together and have identical values, which is quite improbable and would normally just be recorded as 2 separate event. I’ll remove bilateral from the value set.
I’d suggest doing like in blood pressure, and make the max constraint <1000 mm, so it works as a sanity check to prevent more than 3 digits. I’d also suggest constraining the max number of decimal digits to 1.
I know I previously suggested the approach you have modelled using Body site plus Laterality, together with the Anatomical location SLOT. On reflection, now that we can see the archetype in front of us, the limited number of body sites and the fact that recording laterality introduces additional data entry effort without adding meaningful value suggest it may be worth reconsidering whether replacing the unlateralised body site concepts with specific precoordinated left and right body site concepts would provide a clearer and simpler solution, allowing both the Laterality qualifier and Anatomical location SLOT to be removed.
Thank you for reconsidering the structure. It’s a helpful reflection, and I can see the reasoning behind this approach - many observation archetypes split anatomical sites to left/right.
However, looking at the body segment archetypes (circumference, length, area), all three use exactly the same Body site + Laterality pattern as my current skinfold archetype, with Laterality offering only Left and Right. My main concern with the precoordinated approach is the size of the resulting value set. If laterality were added to all 12 sites, the value set would grow to 24 codes, many of which would never be used in practice. Is such a large value set within acceptable bounds for CKM, or is there a preferred way to handle this? If it is, we’re happy to go with the precoordinated approach and remove the Laterality element and Anatomical location SLOT like you proposed. If not, we’d suggest keeping the current two-field structure (Body site + Laterality) as a more compact alternative.
Happy to go whichever way you and Silje think works best for long-term CKM maintainability.
I think there is a subtle modelling point that is worth drawing out, and I’m well aware that I’ve contributed to the confusion by previously suggesting alignment with the Body segment family.
We shouldn’t necessarily expect all archetypes that involve body sites to use exactly the same design pattern. Each archetype should be designed according to its own purpose and anticipated patterns of use. Most importantly, the design should be driven by the expected range of body sites to be represented, which is why I previously asked you to suggest the anticipated site list.
As I’ve come to better understand the requirements for skinfold measurement, it has become apparent that the body site models used in the body segment archetypes and the skinfold measurement archetype have different scopes and therefore require different design trade-offs. The body segment archetypes are intended to support a much broader and potentially extensible range of anatomical locations. In that context, separating Body site and Laterality allows the body site value set to evolve independently of laterality, supports reuse of a large SNOMED CT value set, and enables laterality to be recorded only where appropriate, since many body sites are not lateralised.
The skinfold measurement archetype is subtly different. The recognised measurement sites are few in number, fixed and well established, and every recognised site requires laterality. In that situation, precoordinating the body site and laterality may actually produce a simpler and clearer model by removing two data elements without sacrificing flexibility. Although this results in approximately 24 coded concepts, that remains a relatively small, fixed value set in which every concept is clinically meaningful and directly selectable.
So my suggestion wasn’t intended as a general CKM design principle, but rather as a possible optimisation for this particular archetype because of its constrained scope.
