HIVARTStagingByCD4Diagnostic

The HIVARTStagingByCD4Diagnostic intervention class builds on the HIVSimpleDiagnostic intervention by checking for treatment eligibility based on CD4 count. It uses the lowest-ever recorded CD4 count for that individual, based on the history of past CD4 counts conducted using the HIVDrawBlood intervention. To specify the outcome based on age bins instead of CD4 testing, use HIVARTStagingCD4AgnosticDiagnostic.

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

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
}

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
}

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_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"
}

If_Active_TB

JSON object

NA

NA

NA

If the individual’s CD4 is not below the threshold in the Threshold table and the individual has TB (via their IndividualProperties), then the individual’s CD4 will be compared to the CD4 value retrieved from the InterpolatedValueMap matrix based on the current year.

{
    "If_Active_TB": {
        "Times": [
            1990,
            1995,
            2000,
            2005
        ],
        "Values": [
            800,
            600,
            550,
            500
        ]
    }
}

If_Pregnant

JSON object

NA

NA

NA

If the individual does not pass the diagnostic from the Threshold or TB matrices, and the individual is pregnant, then the individual’s CD4 is compared to the value found in the InterpolatedValueMap matrix.

{
    "If_Pregnant": {
        "Times": [
            1990,
            1995,
            2000,
            2005
        ],
        "Values": [
            600,
            500,
            450,
            400
        ]
    }
}

Individual_Property_Active_TB_Key

string

NA

NA

UNINITIALIZED

The IndividualProperty key (‘HasActiveTB’) used to determine whether the individual has TB.

{
    "Individual_Property_Active_TB_Key": "HasActiveTB"
}

Individual_Property_Active_TB_Value

string

NA

NA

UNINITIALIZED

The IndividualProperty value (‘Yes’) used to determine whether the individual has TB.

{
    "Individual_Property_Active_TB_Value": "YES"
}

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_Name": "Diagnostic_Sample"
}

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.

{
    "Event_Or_Config": "Event",
    "Negative_Diagnosis_Event": "PreDebut"
}

New_Property_Value

string

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"
}

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
    }
}

Threshold

JSON object

NA

NA

NA

If the individual’s CD4 has ever been below the threshold specified, then the test will be positive.

{
    "Threshold": {
        "Times": [
            1990,
            1995,
            2000,
            2005
        ],
        "Values": [
            500,
            400,
            350,
            300
        ]
    }
}

Times

array of floats

0

999999

NA

An array of years.

{
    "Times": [
        1998,
        2000,
        2003,
        2006,
        2009
    ],
    "Values": [
        0,
        0.26,
        0.08,
        0.14,
        0.54
    ]
}

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
    }
}
{
    "Campaign_Name": "2a_UniversalART",
    "Default_Campaign_Path": "defaults/hiv_default_campaign.json",
    "Use_Defaults": 1,
    "Events": [{
        "class": "CampaignEventByYear",
        "Event_Name": "ARTStaging: state 6 (check eligibility for ART by CD4)",
        "Start_Year": 1990,
        "Nodeset_Config": {
            "class": "NodeSetAll"
        },
        "Event_Coordinator_Config": {
            "class": "StandardInterventionDistributionEventCoordinator",
            "Intervention_Config": {
                "class": "NodeLevelHealthTriggeredIV",
                "Trigger_Condition_List": [
                    "ARTStaging6"
                ],
                "Actual_IndividualIntervention_Config": {
                    "class": "HIVARTStagingByCD4Diagnostic",
                    "Disqualifying_Properties": [
                        "InterventionStatus:LostForever",
                        "InterventionStatus:OnART",
                        "InterventionStatus:LinkingToART",
                        "InterventionStatus:OnPreART",
                        "InterventionStatus:LinkingToPreART"
                    ],
                    "New_Property_Value": "InterventionStatus:ARTStaging",
                    "Threshold": {
                        "Times": [
                            2004,
                            2011.8,
                            2015,
                            2020
                        ],
                        "Values": [
                            200,
                            350,
                            500,
                            1000000
                        ]
                    },
                    "If_Pregnant": {
                        "Times": [
                            2010.34,
                            2015
                        ],
                        "Values": [
                            350,
                            1000
                        ]
                    },
                    "If_Breastfeeding": {
                        "Times": [
                            2004
                        ],
                        "Values": [
                            0
                        ]
                    },
                    "Event_Or_Config": "Event",
                    "Positive_Diagnosis_Event": "LinkingToART0",
                    "Negative_Diagnosis_Event": "LinkingToPreART0"
                }
            }
        }
    }]
}