Re: [Gnumed-devel] clin_medication

[Karsten Hilbert]

> >I vote for frequency as a number in hours, this covers hourly eye drops
> >to weekly bisphosphonates.
> 
> Frequency -- if it means bid, tid, qid etc (or is there some other 
> preferred term for this?) -- has to be distinguished from "period" 
> which in the schema is
>       integer, NOT NULL, the length of the dosing cycle, in hours
> 
> the commonest value for "period" would be 24, because it is only when 
> the dosage is NOT the same every day that one would change this. 

It is now this:

dosage: array of numeric (eg. "better float")
period: interval no default (== MUST set this!)

Sounds fair ?

> Examples would include:
> 
> - alternate day corticosteroids
dosage: [1] in <dosage_unit>
period: '2 days'

> - cycling hormonal therapy and chemotherapy

> - warfarin dosed at 4mg Mondays, Wednesdays, Fridays vs 3mg on the other days
dosage: [4,3,4,3,4,3,3] in <dosage_unit:mg>
period: '1 week'

> I would suggest a default of 24h unless it is preferred that this be 
> assigned by a widget?
The user would *always* have control over the period. This is
a medical decision not to be influenced by a DB designer's
default attitude.

> I cannot think of an *outpatient* situation where the "cycle" would 
> be less than 24 hours, only hospital-based, for example intravenous 
> infusions at varying rates (iron, N-acetylcysteine). Am I overlooking 
> other candidate use cases?
Well :-)  Antipyretics:  1 Supp every 8 hours:

Paracetamol

 dosage_unit: [250] mg
 period: '8 hours'

which is the same as

 dosage_unit: [250, 250, 250] mg
 period: '24 hours'

It's up to the discretion of the health professional to decide
what serves the patient better: "one every 8 hours" or "3 per
day". Some parents are challenged to correctly comprehend the
latter. Some even need "one each at hours 6, 14, 22". Mind
you, those parents are often keen to do the right thing. It's
just that they can't remember/comprehend...

> For the "period", 168 is awkward to input, when one intends "weekly".
Which is why it's an "interval" field. So just put in '1
week'. Computation will be handled correctly by PostgreSQL.

> We might use the concept d for days, w for weeks hence 7d would be 
> translated to 168 hours
In a widget, perhaps, not in the database.

> What field  should carry the bid tid etc?
clin_medication.directions - free text

> While this could be 
> relegated to a free text field, a lookup table could permit mapping 
> to the numeric value for how often per day which, when combined with 
> the dosage can help calculate how much (how many tablets) to supply.
In a widget I'd rather do this: When the user enters
dosage/period calculate tid/bid whatever from it. If a result
is obtained put that into directions. When the user enters
directions scan for tid/bid/etc and warn if dosage/period is
not matching. The easier solution would be to disallow
entering tid/bid in directions if dosage/period had been
entered. If dosage/period had not been entered previously and
directions are entered then dosage/period can be looked up.

> PS in the schema, in place of "dose", can I propose "dosage"?
done

I am attaching the entire table in it's current form for
reference and comment.

Karsten
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clin_medication.sql
Description: Text document