We have recently spent some time on digging into the different types of dates (timestamps) that are needed for planning various types of services, e.g. surgical procedures.
An area of confusion is around what in the ServiceRequest archetype is called Service Due. If we look at its definition, it says:
Description = The date/time, or acceptable interval of date/time, for provision of the service
Comment = This data element allows for recording of the timing for a single service, either as a date and time, a date ranges or a text descriptor which can allow for 'next available. In practice, clinicians will often think in terms of ordering services as approximate timing, for example: review in 3 months, 6 months or 12 months. As clinical systems need more exact parameters to operate on, this ‘3 months’ will usually be converted to an exact date 3 months from the date of recording and stored using this data element. If complex timing or sequences of timings are required, use the CLUSTER.service_direction archetype within the ‘Complex timing’ SLOT and this data element becomes redundant
We have a corresponding national definition in Sweden which translates to something like: “Medical Target Date”, and defined something like “The date for which healthcare activities should commence”.
What we have realized is that there seems to be at least two different concepts mixed in the Swedish national definition, and also seems to be mixed up in the openEHR ServiceRequest. The naming here could likely be improved, but you have these two types at least:
Latest target date
A date which indicates that the start of the treatment should not happen after this date, but the patient is benefited from it being started sooner. Resource constraints are the likely reason for not delivering the service sooner. Example use cases are:
- Activities associated with waiting time targets where the patient should not wait longer than x time for a first visit or treatment start
- Activities that are critical to the patients health where the services should not be delivered later than x time due to health risk reasons
Approximate target date
A date that indicates that the service should be delivered x time in the future based on some rough period (1 day, 1 week, 1 month, 6 months…). Even if there are resources available before x time from now, it is not sure that the service should be planned sooner. There is an intent of the wait itself. The time passing has a value. It is not intended to be performed on this exact time, it is seen as approximate. Example use cases could be:
- Follow up appointments and activities associated with them
- Recurring treatments and checkups for chronic patients
When I read the description of Service due it sounds to be like what I refer to as an “approximate target date”. But that is not the only use case.
When digging into it more there are potentially other dates as well. Sometimes you want an Explicit target date, e.g. when coordinating multiple services at once. Lets say that the patient has a surgery planned already for a certain date. And you want to also perform a second procedure at the same time to avoid forcing the patient to be admitted at two different occasions, not performing the anesthetic twice etc. That I do not see as either a “Latest” or an “Approximate” date.
I guess my question is:
How should we distinguish these different timing concepts in the ServiceRequest?