AntiretroviralTherapy¶
The AntiretroviralTherapy intervention class begins antiretroviral therapy (ART) for specified individuals. To remove an individual from ART, use ARTDropout.
Additional considerations when using this intervention:
The model will not allow someone who is HIV negative to be put on ART.
A person who has not previously been on ART is considered to be ‘starting ART’ at the time this intervention is applied; the model will track this start time/duration.
If a person is already on ART from another intervention, receiving a second ART intervention will have no effect.
If a person is on already ART and receives the ARTMortalityTable intervention, the original ART start time will be used to calculate the duration from enrollment to ART AIDS Death. The duration since starting ART will not change; it will continue to increase.
If a person is on ART and receives the ARTDropout intervention, the person will go off ART and the duration will be reset; if receiving a new ART intervention, this new start time/duration will be used in any calculations.
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 |
|---|---|---|---|---|---|---|
ART_CD4_at_Initiation_Saturating_Reduction_in_Mortality |
float |
0 |
3.40282e+38 |
350 |
The duration from ART enrollment to on-ART HIV-cause death increases with CD4 at ART initiation up to a threshold determined by this parameter value. This is the maximum value that CD4 is allowed to have in the hazard ratio calculation for CD4. |
{
"ART_CD4_at_Initiation_Saturating_Reduction_in_Mortality": 350
}
|
ART_Is_Active_Against_Mortality_And_Transmission |
boolean |
0 |
1 |
1 |
If set to true (1), ART will suppress viral load and extend prognosis. |
{
"ART_Is_Active_Against_Mortality_And_Transmission": 1
}
|
ART_Multiplier_On_Transmission_Prob_Per_Act |
float |
0 |
1 |
0.08 |
Multiplier acting on Base_Infectivity to determine the per-act transmission probability of a virally suppressed HIV+ individual. |
{
"ART_Multiplier_On_Transmission_Prob_Per_Act": 0.08
}
|
ART_Survival_Baseline_Hazard_Weibull_Scale |
float |
1e-06 |
1e+06 |
123.83 |
Scale parameter for a Weibull distribution of survival time in years for a male < 40 with WHO stage of 1 or 2 starting ART (base case). |
{
"ART_Survival_Baseline_Hazard_Weibull_Scale": 123.83
}
|
ART_Survival_Baseline_Hazard_Weibull_Shape |
float |
0 |
10 |
0.34 |
Shape parameter for a Weibull distribution of survival time in years for a male < 40 with WHO stage of 1 or 2 starting ART (base case). |
{
"ART_Survival_Baseline_Hazard_Weibull_Shape": 0.34
}
|
ART_Survival_Hazard_Ratio_Age_Over_40Yr |
float |
1e-06 |
1e+06 |
1.4309 |
The hazard ratio comparing the survival time of those starting ART over 40 years of age compared to those starting ART <40 years. |
{
"ART_Survival_Hazard_Ratio_Age_Over_40Yr": 1.4309
}
|
ART_Survival_Hazard_Ratio_Body_Weight_Kg_Intercept |
float |
1e-06 |
1e+06 |
3.05043 |
The Y-intercept to use when calculating the hazard ratio for the person’s body weight. The body weight is determined by WHO stage:
multiplier = exp(weight_slope * weight + weight_intercept) |
{
"ART_Survival_Hazard_Ratio_Body_Weight_Kg_Intercept": 3.05043
}
|
ART_Survival_Hazard_Ratio_Body_Weight_Kg_Slope |
float |
1e-06 |
1e+06 |
-0.073153 |
The slope to use when calculating the hazard ratio for the person’s body weight. The body weight is determined by WHO stage:
multiplier = exp(weight_slope * weight + weight_intercept) |
{
"ART_Survival_Hazard_Ratio_Body_Weight_Kg_Slope": -0.073153
}
|
ART_Survival_Hazard_Ratio_CD4_Intercept |
float |
1e-06 |
1e+06 |
0.282852 |
The Y-intercept to use when calculating the hazard ratio for the person based on their CD4 count. multiplier = exp(cd4_slope * cd4 + cd4_intercept) |
{
"ART_Survival_Hazard_Ratio_CD4_Intercept": 0.282852
}
|
ART_Survival_Hazard_Ratio_CD4_Slope |
float |
1e-06 |
1e+06 |
-0.00758256 |
The slope value to sue when calculating the hazard for for the person based on their CD4 count. multiplier = exp(cd4_slope * cd4 + cd4_intercept) |
{
"ART_Survival_Hazard_Ratio_CD4_Slope": -0.00758256
}
|
ART_Survival_Hazard_Ratio_Female |
float |
1e-06 |
1e+06 |
0.6775 |
The hazard ratio comparing survival female to male survival for those starting ART. |
{
"ART_Survival_Hazard_Ratio_Female": 0.6775
}
|
ART_Survival_Hazard_Ratio_WHO_Stage_3Plus |
float |
1e-06 |
1e+06 |
2.7142 |
The hazard ratio comparing those starting ART in WHO stage >= 3 to those in WHO stage < 3. |
{
"ART_Survival_Hazard_Ratio_WHO_Stage_3Plus": 2.7142
}
|
ART_Survival_WHO_Stage_Threshold_For_Cox |
float |
0 |
5 |
3 |
If the person receiving ART has a WHO Stage greater than or equal to this threshold, then use the hazard ratio determined by the parameter ART_Survival_Hazard_Ratio_WHO_Stage_3Plus. |
{
"ART_Survival_WHO_Stage_Threshold_For_Cox": 3
}
|
Cost_To_Consumer |
float |
0 |
99999 |
1 |
Unit cost per drug (unamortized). |
{
"Cost_To_Consumer": 1
}
|
Days_To_Achieve_Viral_Suppression |
float |
0 |
3.40282e+38 |
183 |
The number of days after ART initiation over which infectiousness declines linearly until the ART_Multiplier_On_Transmission_Prob_Per_Act takes full effect. |
{
"Days_To_Achieve_Viral_Suppression": 183
}
|
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
}
|
Intervention_Name |
string |
NA |
NA |
AntiretroviralTherapy |
The optional name used to refer to this intervention as a means to differentiate it from others that use the same class. |
{
"Intervention_Config": {
"Intervention_Name": "Standard of care",
"class": "AntiretroviralTherapy"
}
}
|
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"
}
|
{
"Campaign_Name": "ARTBasic intervention test",
"Use_Defaults": 1,
"Events": [
{
"Description": "New infections get immediate ART",
"class": "CampaignEvent",
"Start_Day": 1,
"Nodeset_Config": {
"class": "NodeSetAll"
},
"Event_Coordinator_Config": {
"class": "StandardInterventionDistributionEventCoordinator",
"Intervention_Config": {
"class": "NodeLevelHealthTriggeredIV",
"Trigger_Condition_List": [
"NewInfectionEvent"
],
"Demographic_Coverage": 1.0,
"Actual_IndividualIntervention_Config": {
"class": "AntiretroviralTherapy",
"Days_To_Achieve_Viral_Suppression": 1000000,
"ART_CD4_at_Initiation_Saturating_Reduction_in_Mortality": 350,
"ART_Is_Active_Against_Mortality_And_Transmission": 1,
"ART_Survival_Hazard_Ratio_Female": 0.6775,
}
}
}
}
]
}