[Immunization] How to calculate DUE dates for dependent Tasks | Code Changes

[dubdabasoduba]

Context

1. [Immunization] How to define tasks dependencies | Content Changes #2141
2. [Immunization] How to define the task timing | Content Changes #2142

Implementation

How to identify the link between the questionnaire items and a Tasks

• Individual tasks form
  • The current FHIR Core implementation already links a Questionnaire and a Task through
    the Task.reasonReference.reference attribute.
  • This is then used to update the Task.status after the Questionnaire is filled and
    the QuestionnaireResponse.status marked as completed.
  • The function to update the DUE dates should be called immediately after updating the Task.status attribute.
• Record all tasks form
  • This form will be used to record administration dates for multiple tasks.
  • The tasks are represented as Questionnaire.item.answerOption on the first question as
    described here.
    • The answer options should have the following characteristics.
      • The Questionnaire.item.answerOption.valueCoding.id as the Task.id.
      • The Questionnaire.item.answerOption.valueCoding.display as the Task.description.
      • The Questionnaire.item.answerOption.valueCoding.code as the Task.id.
  • Based on the option we go with here, we have 2 options on
    how to generate the inputs for the update DUE dates function below.
    1. Tasks completion via StructureMaps
       1. The extracted resources are added as contained resources on the QuestionnaireResponse.contained
          attribute. Iterate through the QuestionnaireResponse.contained to get the Tasks then use the Tasks list
          to generate the input for the update DUE function below.
    2. Tasks completion via code
       1. Write a function to extract the Task.id from the resulting QuestionnaireResponse.item.answer array
          and fetch the tasks related to the fetched ids from the local app database.
       2. Use the resulting tasks list to generate the input for the update DUE date function below.

How to calculate DUE dates for dependent Tasks

• Write a function that runs immediately after a Task is completed.
• This function will update the date on the Task.excecutionPeriod.start attribute to account for the prerequisite
  administration date.
  • This will affect the time the Task becomes DUE.
  • The method should only execute if
    • The dependent task has the prerequisite referenced on the Task.partOf attribute.
    • If the dependent task is DUE, UPCOMING or OVERDUE.
    • The dependent task has an Task.input.type attribute defined with
      the {"coding":[{"system":"http://snomed.info/sct","code":"371154000","display":"Dependent (qualifier value)"}]}.
    • The Task should also have the prerequisite tasks referenced on the Task.input attribute with the reference
      code on the Task.input.type attribute.
      • Here is an
        example {"type":{"coding":[{"system":"http://snomed.info/sct","code":"900000000000457003","display":"Reference set attribute (foundation metadata concept)"}]},"reference":"Task/<string-uuid>"}.
• The new Task.excutionPeriod.start date will be calculated as follows
  • Get the administration date added to the Immunization recording QuestionnaireResponse.
    • Let's call it administration_date. This can be found on the immunization resource here [Immunization] How to define the task timing | Content Changes #2142
  • Subtract the administration_date from the dependent task Task.excutionPeriod.start to get the number of days
    between the 2 dates.
    • Let's call the difference date_interval.
  • Check if the date_interval is => to the time interval (e.g. 28) defined on the dependent
    task Task.input.value here.
    • If yes, do nothing. otherwise, add the time interval provided on the dependent task Task.input.value to
      the administration_date and update the dependent task Task.excutionPeriod.start to the results.

[pld]

• "The worker should only run if" isn't it that the worker always runs, but the below specifies what Tasks the worker searches for to update?
• Are these 2 bullets saying the same/an equivalent thing?

• The dependent task has an input.type attribute defined with
  the {"coding":[{"system":"http://snomed.info/sct","code":"900000000000457003","display":"Reference set attribute (foundation metadata concept)"}]}.
• The Task should also have the prerequisite tasks referenced on the input attribute with the reference code
  on the input.type attribute.
  • Here is an example {"type":{"coding":[{"system":"http://snomed.info/sct","code":"900000000000457003","display":"Reference set attribute (foundation metadata concept)"}]},"reference":"Task/"}.

• How is the "Immunization recording form" linked to the Task?
• Can we make explicit somewhere that the value in Task.input.value is in days?

[dubdabasoduba]

Updated.