edc-visit-tracking 0.2.42

Base classes for visit reports/tracking in clinicedc/edc.

edc-visit-tracking

Track study participant visit reports.

Declaring a visit model

A visit_model is declared using the model mixin VisitModelMixin. Normally, a visit_model will be declared with additional model mixins, but VisitModelMixin must be there.

class SubjectVisit(VisitModelMixin, BaseUuidModel):
    ...

Also, ensure the Meta class attributes of VisitModelMixin are inherited. These include required constraints and ordering.

class SubjectVisit(VisitModelMixin, BaseUuidModel):

    ...

    class Meta(VisitModelMixin.Meta):
        pass

Among other features, VisitModelMixin adds a OneToOneField foreign key to the visit_model that points to edc_appointment.Appointment.

Important: A visit model is a special model in the EDC. A model declared with the model mixin, VisitModelMixin, is the definition of a visit model. CRFs and Requisitions have a foreign key pointing to a visit model. A number of methods on CRFs and Requisitions detect their visit model foreign key name, model class and value by looking for the FK declared with VisitModelMixin.

For a subject that requires ICF the visit model would look like this:

class SubjectVisit(VisitModelMixin, OffstudyMixin, CreatesMetadataModelMixin,
                   RequiresConsentModelMixin, BaseUuidModel):

    class Meta(VisitModelMixin.Meta):
        consent_model = 'myapp.subjectconsent'  # for RequiresConsentModelMixin

If the subject does not require ICF, such as an infant, don’t include the RequiresConsentModelMixin:

class InfantVisit(VisitModelMixin, OffstudyMixin,
                  CreatesMetadataModelMixin, BaseUuidModel):

    class Meta(VisitModelMixin.Meta):
        pass

Declaring a CRF

The CrfModelMixin is required for all CRF models. CRF models have a OneToOneField key to a visit model.

class CrfOne(CrfModelMixin, OffstudyCrfModelMixin, RequiresConsentModelMixin,
             UpdatesCrfMetadataModelMixin, BaseUuidModel):

    subject_visit = models.OneToOneField(SubjectVisit)

    f1 = models.CharField(max_length=10, default='erik')

    vl = models.CharField(max_length=10, default=NO)

    rdb = models.CharField(max_length=10, default=NO)

    class Meta:
        consent_model = 'myapp.subjectconsent'  # for RequiresConsentModelMixin

Declaring forms:

The VisitFormMixin includes a number of common validations in the clean method:

class SubjectVisitForm(VisitFormMixin, forms.ModelForm):

    class Meta:
        model = SubjectVisit

PreviousVisitModelMixin

The PreviousVisitModelMixin ensures that visits are entered in sequence. It is included with the VisitModelMixin.