HIVDrawBlood

The HIVDrawBlood intervention class builds on HIVSimpleDiagnostic to represent phlebotomy for CD4 or viral load testing. It allows for a test result to be recorded and used for future health care decisions, but does not intrinsically lead to a health care event. A future health care decision will use this recorded CD4 count or viral load, even if the actual CD4/viral load has changed since last phlebotomy. The result can be updated by distributing another HIVDrawBlood intervention.

Note

Parameters are case-sensitive. For Boolean parameters, set to 1 for true or 0 for false. Minimum, maximum, or default values of “NA” indicate that those values are not applicable for that parameter.

EMOD does not use true defaults; that is, if the dependency relationships indicate that a parameter is required, you must supply a value for it. However, many of the tools used to work with EMOD will use the default values provided below.

JSON format does not permit comments, but you can add “dummy” parameters to add contextual information to your files. Any keys that are not EMOD parameter names will be ignored by the model.

The table below describes all possible parameters with which this class can be configured. The JSON example that follows shows one potential configuration.

Parameter

Data type

Minimum

Maximum

Default

Description

Example

Cost_To_Consumer

float

0

3.40282e+38

1

The unit ‘cost’ assigned to the diagnostic. Setting Cost_To_Consumer to zero for all other interventions, and to a non-zero amount for one intervention, provides a convenient way to track the number of times the intervention has been applied in a simulation.

{
    "Cost_To_Consumer": 0.333
}

Days_To_Diagnosis

float

0

3.40282e+38

0

The number of days from test until positive diagnosis. A negative test result is given immediately when the intervention is distributed.

{
    "Days_To_Diagnosis": 0.0
}

Enable_Is_Symptomatic

boolean

0

1

0

If true (1), requires an infection to be symptomatic to return a positive test.

{
    "Enable_Is_Symptomatic": 1,
    "Base_Specificity": 0.85,
    "Base_Sensitivity": 0.92
}

Event_Or_Config

enum

NA

NA

Config

Specifies whether the current intervention (or a positive diagnosis, depending on the intervention class) distributes a nested intervention (the Config option) or an event will be broadcast which may trigger other interventions in the campaign file (the Event option). Possible values are:

  • Event

  • Config

{
    "Event_Or_Config": "Config"
}

Negative_Diagnosis_Event

enum

NA

NA

“”

If an individual tests negative, this specifies an event that may trigger another intervention when the event occurs. Only used when Event_Or_Config is set to Event. See Event list for possible values.

{
    "Negative_Diagnosis_Event": "PreDebut"
}

Positive_Diagnosis_Config

JSON object

NA

NA

NA

The intervention distributed to individuals if they test positive. Only used when Event_Or_Config is set to Config.

{
    "Event_Or_Config": "Config",
    "Positive_Diagnosis_Config": {
        "class": "SimpleVaccine",
        "Cost_To_Consumer": 0.333,
        "Secondary_Decay_Time_Constant": 1,
        "Vaccine_Take": 1,
        "Vaccine_Type": "AcquisitionBlocking",
        "Waning_Config": {
            "Box_Duration": 3650,
            "Initial_Effect": 0.1,
            "class": "WaningEffectBox"
        }
    }
}

Positive_Diagnosis_Event

enum

NA

NA

“”

If the test is positive, this specifies an event that can trigger another intervention when the event occurs. Only used if Event_Or_Config is set to Event. See Event list for possible values.

{
    "Intervention_Config": {
        "class": "SimpleDiagnostic",        
        "Base_Sensitivity": 1.0,
        "Base_Specificity": 1.0,
        "Cost_To_Consumer": 0.0,
        "Days_To_Diagnosis": 0.0,
        "Event_Or_Config": "Event",
        "Positive_Diagnosis_Event": "TestedPositive_CureMeNow",
        "Treatment_Fraction": 1.0
    }
}

Treatment_Fraction

float

0

1

1

The fraction of positive diagnoses that are treated or given the Positive_Diagnosis_Config or Positive_Diagnosis_Event when used in campaign classes that trigger separate interventions or events upon a positive diagnosis.

{
    "Intervention_Config": {
        "class": "SimpleDiagnostic",
        "Base_Sensitivity": 1.0,
        "Base_Specificity": 1.0,
        "Cost_To_Consumer": 0.0,
        "Days_To_Diagnosis": 0.0,
        "Event_Or_Config": "Event",
        "Positive_Diagnosis_Event": "TestedPositive_CureMeNow",
        "Treatment_Fraction": 1.0
    }
}
{
  "Use_Defaults": 1,
  "Campaign_Name": "DrawBlood validation",
  "Events": [
    {
      "class": "CampaignEvent",
      "Event_Name": "starting on day 8, give everyone a repeated 2-day delayed intervention",
      "Start_Day": 8,
      "Nodeset_Config": {
        "class": "NodeSetAll"
      },
      "Event_Coordinator_Config": {
        "class": "StandardInterventionDistributionEventCoordinator",
        "Demographic_Coverage": 1,
        "Intervention_Config": {
          "class": "HIVDelayedIntervention",
          "Disqualifying_Properties": [
            "InterventionStatus:InterventionStatus_1",
            "InterventionStatus:InterventionStatus_2",
            "InterventionStatus:InterventionStatus_3"
          ],
          "New_Property_Value": "InterventionStatus:InterventionStatus_4",
          "Single_Use": 1,
          "Delay_Period_Distribution": "CONSTANT_DISTRIBUTION",
          "Delay_Period_Constant": 2,
          "Broadcast_Event": "HIVNeedsHIVTest"
        }
      }
    },
    {
      "class": "CampaignEvent",
      "Event_Name": "DrawBlood event",
      "Start_Day": 1,
      "Nodeset_Config": {
        "class": "NodeSetAll"
      },
      "Event_Coordinator_Config": {
        "class": "StandardInterventionDistributionEventCoordinator",
        "Event_Name": "DrawBlood constant test, broadcasts HIVPositiveHIVTest",
        "Demographic_Coverage": 1,
        "Intervention_Config": {
          "class": "NodeLevelHealthTriggeredIV",
          "Trigger_Condition_List": [
            "HIVNeedsHIVTest"
          ],
          "Demographic_Coverage": 1,
          "Duration": 14600,
          "Actual_IndividualIntervention_Config": {
            "class": "HIVDrawBlood",
            "Positive_Diagnosis_Event": "HIVPositiveHIVTest",
            "Base_Specificity": 0,
            "Base_Sensitivity": 0,
            "Cost_To_Consumer": 10,
            "Days_To_Diagnosis": 0,
            "Disqualifying_Properties": [
              "InterventionStatus:InterventionStatus_1",
              "InterventionStatus:InterventionStatus_2",
              "InterventionStatus:InterventionStatus_3"
            ],
            "New_Property_Value": "InterventionStatus:InterventionStatus_4"
          }
        }
      }
    }
  ]
}