Re: [Gnumed-devel] proper English term needed for medication

[Karsten Hilbert]

On Thu, Oct 29, 2009 at 12:47:43PM -0700, Jim Busser wrote:

> >>What column will this be?
> >
> >     clin.substance_intake.is_long_term
> 
> Is it better boolean as above or would it be better to be categorical
> 
>       clin.substance_intake.category
> 
>       values {short-term, long-term, NULL} default = NULL

:-)

Remember that SQL has three-valued logic, so the above is
True, False, NULL anyway (because I made is_long_term
nullable).

> Also in this table, I wondered for a moment I wondered whether
> .duration could take either an interval-based value (when known
> exactly) or when not known exactly could take the value of short-
> term or long-term
> 
> I suspect the data type "interval" would allow only a time-based
> value therefore it would have to be some other field.

That would be a goog option. I considered doing so. Null
would mean unknown. Infinity would mean long-term. Minus
infinity would mean short-term. Anything else would be a
true duration. Unfortunately, interval doesn't yet support
infinity. I talked to the PostgreSQL about that. They are
working on it.

> if duration is null, the category of medication could be short-term
> or long-term

yes

> if the medication category is long-term, does that mean the duration
> should be nulled?

yes, and it is (by the cConsumedSubstance class):

        duration = (
                case
                        when %(is_long_term)s is True then null
                        else gm.nullify_empty_string(%(duration)s)
                end
        )::interval,

> do we acknowledge potential ambiguity between
>       duration as "intended"
>       duration as "elapsed time since started .clin_when"
>       duration as 'how long did they take it, if they stopped on or
> before today"

That is currently at the discretion of the clinician (due to
lack of more fields). Intended is "intended if .started +
.duration > today, else hopefully how long actually taken".

IOW:

if (.started + .duration) < today then we would strive to
make it how-long-actually-taken

if (.started + .duration) > today then current treatment
intent

> if a duration is specified and is understood to mean "as intended or
> post-hoc actual", should a specified duration be construed to mean
> short-term, or maybe still the medication could be intended as long-
> term with the duration used to pre-specify a plan of reassessment?

It could, yes.

> If the latter, then there would be neither conceptual nor
> programmatic linkage between duration and category, and the meaning
> of duration should be clarified to be
> 
>       Intended duration of use (whether total, or until reassessment), or
> actual duration if stopped, if known

yes, see above

Karsten
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