Re: [Gnumed-devel] Measurements (was: New developer searching for a task)

[Christof Meigen]

Hi,


Karsten Hilbert <address@hidden> writes:
> You are most welcome to do so ! Please feel free to
> incorporate/discuss/reuse/change the lab tables that I
> checked in already. 

Looking at those reminded me why I didn't start working on this in the
first place ... I simply do not know anything about how this works in
medical practice.

Ok, here are my comments:

- there should be no difference whether a value is checked in a lab or
  directly at a clinical encounter (which is probably easy by entering
  the own practice as a lab) (and yourself as 'whom to call for
  medical questions' ;-)

- there may be devices (measurement equipment/biosensors) or methods
  that are not specific to some lab, so it might make sense to have
  the information "HB measured with equipment X" (but probably your
  lab won't tell you), but BioTech is booming and there will be more
  and more devices directly usable by the Doctor

- I do not know about the "ELV", but something like 'range_male' seems
  suspucious to me, since a lot of parameters are (at least!)
  age-dependent.  

- about the 'abnormal_flag': When the IFG is checked in Leipzig, a
  SDS-value is returned, which might be stored in the 'abnormal_flag',
  but of course you have to store that the value of the abnormal_flag
  actually _is_ an SDS-value

- I would perhaps allow an n:m relation between tests and clinical
  episodes

- My general intention would be to leave the decision what value is
  normal and what not to the doctor, based on the avaliable information
  on the patient (age, diagnosis, smoker etc) and published norms.
  I see that this is strongly against the intention of Labs, who
  probably claim to be the only ones who know how to judge the things
  they measured (and don't publish how they come to that judgement).
  
- Imagine a doctor changes Labs, and a value of a patient is marked
  abnormal, when the very same value two weeks ago was judged
  'normal'. This _might_ be because the first lab measured with a 
  different method (which for example has a larger error, so the
  slightly abnormal measurement was still marked normal) but
  it also might be because the first Lab just used a different
  norm.

- Hm. On the one side, you have to be able to store and display the
  test results (incl. judgement of normality) as they come from the
  lab. On the other side, the doctor should perhaps be able to apply
  more modern or more specific norms to the values. And of course,
  judgements should be standardized (one might simply say
  "normal/abnormal", the other provides a SDS-Value, the next one a
  centile, and the third gives his own coding scheme?) ... so, while
  the judgement by the Lab is static, the judgement by availiable
  norms is dynamic data calculated from the norms and the value and
  should not be stored

- Why is the value of a measurement a Character, not a float/double?
  (and why is the "unit"-_reference_ a "character"?)

So much for now,
        Christof