In Opal a Patient may have one or many Episodes. An Episode contains some metadata such as a start and end date, and the type of episode. This may be an inpatient stay, an outpatient treatment, a telephone consultation - or any other arbitrarily defined period of care.
An episode must have a related category. An Opal
EpisodeCategory is a discoverable
opal.core.episodes.EpisodeCategory - such as
You can access the current category of an episode via the
category property, while
it is represented in the database in the field
category_name which will contain
display_name attribute of the relevant category.
episode = patient.episode_set.first() print episode.category # <opal.core.episode.InpatientEpisode object> print episode.category.display_name # "Inpatient" print episode.category_name # "Inpatient"
The category of an episode determines which template will be used to display it
on the detail page for the patient. This template is determined by looking up
detail_template attribute of the
episode.category print episode.category # <opal.core.episode.InpatientEpisode object> print episode.category.detail_template # detail/inpatient.html
The Episode Category template does not comprise the entire Patient detail view. This is made of multiple episodes and by default will display some basic demographic details as well as other episodes. More detail on customising the rest of the detail tempalte is found in the detail view Template selection docs.
The default category of episodes in an Opal application is set by the OpalApplication object's default_episode_category property.
class Application(application.OpalApplication): default_episode_category = MyCategory.display_name
Defining your own EpisodeCategory
As EpisodeCategory is a discoverable we can define our own to meet custom requirements.
Episode categories should be defined in a file named
your application or plugin.
# yourapp/episode_categories.py from opal.core import episodes class DropInClinicEpisode(episodes.EpisodeCategory): display_name = "Drop-in clinic" detail_template = "detail/drop_in.html"
.active is used to distinguish Episodes which are ongoing. This field
is set implicitly by the
Episode.save() method, and there will generally be no
need to set this field directly as part of application code.
Whether an Episode is considered active is determined by the
of the relevant EpisodeCategory.
The default implementation considers any Episode without an
.end date to be active
and any Episode with one to be inactive.
Applications may customise this behaviour by overriding the
For instance, to create a category which considered any Episode older than 2 weeks to be inactive, one might override the method as follows:
# yourapp/episode_categories.py import datetime from opal.core import episodes class TwoWeeksAndStopCaringEpisode(episodes.EpisodeCategory): def is_active(self): delta = datetime.date.today() - self.episode.start return bool(delta >= datetime.timedelta(days=14))
(Note that this would not alter the value in the database immediately after those 2
weeks, but would alter the value the next time the
Episode.save() method was called.)
An Episode will frequently consist of a number of possible stages. For instance, for an inpatient episode, a patient will first be an inpatient, and then an be discharged, with an optional interim follow up stage for inpatients who have been discharged but requrie further follow up.
Opal stores the stage of an episode as a string in the
stage property of an
Episode. The valid possible stages for a category are accessed from the
get_stages method of the category.
episode.category.get_stages() # ['Inpatient', 'Followup', 'Discharged'] episode.category.has_stage('Followup') # True