CD4Diagnostic

The CD4Diagnostic intervention class is similar to SimpleDiagnostic, but adds the ability to divide individual populations based on configurable CD4 count ranges. It uses the individual’s current actual CD4 count, regardless of when a CD4 test has been performed. An event can then be applied based on the Low or High group to which the individuals have been moved.

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 does not permit comments, but you can add “dummy” parameters to add contextual information to your files.

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

Base_Sensitivity

float

0

1

1

The sensitivity of the diagnostic. This sets the proportion of the time that individuals with the condition being tested receive a positive diagnostic test. When set to 1, the diagnostic always accurately reflects the condition. When set to zero, then individuals who have the condition always receive a false-negative diagnostic test.

 
{
    "Base_Sensitivity": 0.8
}

Base_Specificity

float

0

1

1

The specificity of the diagnostic. This sets the proportion of the time that individuals without the condition being tested receive a negative diagnostic test. When set to 1, the diagnostic always accurately reflects the lack of having the condition. When set to zero, then individuals who do not have the condition always receive a false-positive diagnostic test.

 
{
    "Base_Specificity": 0.9
}

CD4_Thresholds

array of JSON objects

NA

NA

NA

This parameter associates ranges of CD4 counts with events that should occur for individuals whose CD4 counts fall into those ranges.

 
{
    "Intervention_Config": {
        "class": "CD4Diagnostic",
        "CD4_Thresholds": [
            {
                "Low": 100,
                "High": 500,
                "Event": "CD4Measured0"
            }
        ]
    }
}

Cost_To_Consumer

float

0

3.40E+3

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

3.40E+3

0

The number of days from test until diagnosis.

 
{
    "Days_To_Diagnosis": 0.0
}

Disqualifying_Properties

array of strings

NA

NA

[]

A list of IndividualProperty key:value pairs that cause an intervention to be aborted (persistent interventions will stop being distributed to individuals with these values). See NodeProperties and IndividualProperties parameters for more information. Generally used to control the flow of health care access. For example, to prevent the same individual from accessing health care via two different routes at the same time.

 
{
    "Disqualifying_Properties": [
        "InterventionStatus:LostForever"
    ]
}

Dont_Allow_Duplicates

boolean

0

1

0

If an individual’s container has an intervention, set to true (1) to prevent them from receiving another copy of the intervention. Supported by all intervention classes.

 
{
    "Dont_Allow_Duplicates": 0
}

Enable_IsSymptomatic

boolean

0

1

0

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

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

Event

string

NA

NA

“”

The user-defined name of the diagnostic event.

 
{
    "Intervention_Config": {
        "class": "CD4Diagnostic",
        "CD4_Thresholds": [
            {
                "Low": 100,
                "High": 500,
                "Event": "CD4Measured0"
            }
        ]
    }
}

High

float

0

1000

NA

The high end of the diagnostic level.

 
{
    "Intervention_Config": {
        "class": "CD4Diagnostic",
        "CD4_Thresholds": [
            {
                "Low": 100,
                "High": 500,
                "Event": "CD4Measured0"
            }
        ]
    }
}

Intervention_Name

string

NA

NA

NA

The optional name used to refer to this intervention as a means to differentiate it from others that use the same class.

 
{
    "Intervention_Config": {
        "class": "CD4Diagnostic",
        "Intervention_Name": "Routine test to update ART treatment"
    }
}

Low

float

0

1000

NA

The low end of the diagnostic level.

 
{
    "Intervention_Config": {
        "class": "CD4Diagnostic",
        "CD4_Thresholds": [
            {
                "Low": 100,
                "High": 500,
                "Event": "CD4Measured0"
            }
        ]
    }
}

New_Property_Value

string

NA

NA

NA

An optional IndividualProperty key:value pair that will be assigned when the intervention is distributed. See NodeProperties and IndividualProperties parameters for more information. Generally used to indicate the broad category of health care cascade to which an intervention belongs to prevent individuals from accessing care through multiple pathways. For example, if an individual must already be taking a particular medication to be prescribed a new one.

 
{
    "New_Property_Value": "InterventionStatus:None"
}

Treatment_Fraction

float

0

1

1

The fraction of positive diagnoses that are treated.

 
{
    "Intervention_Config": {
        "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,
        "class": "SimpleDiagnostic"
    }
}

{
    "Campaign_Name": "4a_ARTRetention_Depends_on_Time_CD4_Demographics",
    "Default_Campaign_Path": "defaults/hiv_default_campaign.json",
    "Use_Defaults": 1,
    "Events": [{
        "class": "CampaignEventByYear",
        "Event_Name": "",
        "Start_Year": 1990,
        "Nodeset_Config": {
            "class": "NodeSetAll"
        },
        "Event_Coordinator_Config": {
            "class": "StandardInterventionDistributionEventCoordinator",
            "Intervention_Config": {
                "class": "NodeLevelHealthTriggeredIV",
                "Trigger_Condition_List": [
                    "OnART1"
                ],
                "Actual_IndividualIntervention_Config": {
                    "class": "CD4Diagnostic",
                    "CD4_Thresholds": [{
                            "Low": 0,
                            "High": 200,
                            "Event": "OnART4"
                        },
                        {
                            "Low": 200,
                            "High": 100000000,
                            "Event": "OnART7"
                        }
                    ]
                }
            }
        }
    }]
}