...don't do that!

The classic response to "Doc, it hurts when I do this", which is an excellent example to use in exploring the various kinds of observations that can be recorded on a problem list using the HL7 Continutity of Care Document Problem Observation Template as profiled in Problem Entry in the IHE PCC Technical Framework and used in the HITSP C32 Specification.

The code element of the problem observation in the IHE template supports on of 7 values reflecting different degrees of clinical judgement.

Code	Description	Degree of clinical judgement
409586006	Complaint	When the patient comes into the office and says "Doc, it hurts when I do this", that's a complaint.
418799008	Symptom	When the doctor asks "Does it hurt when you do this, and the paitent responds affirmatively", that's a symptom.  Usually occuring during review of symptoms, although also found during history taking.
404684003	Finding	When the doctor says "Does it hurt when I do this," flexes your ankle, and he/she observes you wince, that's a clinical finding.  Usually occuring during a physical examination.
282291009	Diagnosis	When the doctor says, "OK, you have sprained your ankle", that's a diagnosis.
64572001	Condition	Other things could also be causing your problem, some of them are not "problems" in and of themselves, but they are medical conditions.  If your ankle pain is due to swollen ankles, brought on by hormonal changes due to pregnancy, hopefully, the condition of pregnancy is not really a "problem".  It is a normal biological process after all.
55607006	Problem	But, that "ankle sprain" certainly is a problem, and the patient could report it as such.
248536006	Functional Limitation	As a result of the ankle sprain, the patient may have difficulty walking or climbing steps.  This is also a problem, but a more specific type of problem, describing a physical limitation for the patient.

The level of clinical judgement is important in understanding what's happening with a problem.  If "ankle pain" is simply listed as a complaint, then more examination is needed.  If it's listed as a diagnosis, then your doctor might want to see what has been done to identify the cause of this otherwise unexplained pain.  In order to reach that stage of clinical decision making, some investigation should have occured to get there.

Usually, "ankle pain" won't appear as a diagnosis, but if that was the reason for the visit, and no other explanation appears to the provider, the final "diagnosis" code appearing on the bill for the visit to your insurer (another reason to avoid use of billing codes) will often be for "ankle pain".

Having identified the level of clinical judgement, the question of where to put the code for ankle pain has probably occured to you.  It codes in the value element of the observation.  This follows the question/answer pattern that is supported by the TERMINFO guide, where the code is the question (what is the complaint/problem/condition/diagnosis et cetera), and the value is the answer.  The HL7 TERMINFO would prefer that the code value be "ASSERTION", but allows for these other codes to be used, because they are "supertypes" of assertion. 

Quite honestly, ASSERTION is a rather weak statement of a fact, because as we've seen above, there are different degrees of confidence and decision making involved in making assertions about patient care. 

That's why IHE chose this represention among the many possible different representations that could have been used for the Problem Entry.