Anemia Module

1.0 Overview 

This document is the page for the anemia YLDs module of the MNCNH Portfolio simulation. The anemia module will process information related to simulants’ hemoglobin exposure throughtout the course of the simulation and calculate corresponding anemia exposure and YLDs.

2.0 Module Diagram and Data 

2.1 Module Diagram 

../../../../_images/anemia_ylds_module_diagram.drawio.png

2.2 Module Inputs 

Hemoglobin module required inputs
Input	Source module	Application	Note
First trimester ANC attendance	ANC module	Determines anemia YLD calculation equation
Hemoglobin at the start of pregnancy	Hemoglobin module	Used to calculate anemia YLDs
Hemoglobin at end of pregnancy	Hemoglobin module	Used to calculate anemia YLDs
Postpartum hemoglobin	Postpartum hemoglobin module	Used to calculate anemia YLDs	Note that this value will be missing for simulants who did not survive labor
IV iron coverage	Hemoglobin module	Determines anemia YLD calculation equation
IFA/MMS coverage	Hemoglobin module	Determines anemia YLD calculation equation
Pregnancy duration	Pregnancy II module	Used to calculate anemia YLDs

2.3 Module Decision Nodes 

Hemoglobin module decision nodes
Decision node	Description	Information
1	Received IFA/MMS?	Yes if IFA/MMS coverage input value == True
2, 4, 5	Received IV iron	Yes if IV iron coverage input value == True
3	Attended first trimester ANC visit	Yes if first trimester ANC attendance input value == True

2.4 Module Action Points 

We assume that hemoglobin may vary throughout the course of pregnancy/postpartum at the following distinct points opportunities: (1) following IFA/MMS supplementation at the first trimester ANC visit, (2) following IFA/MMS supplementation or IV iron administration at the later pregnancy ANC visit, and (3) following an incident case of maternal hemorrhage during labor, which will persist through the end of the postpartum period. Therefore, we will calculate YLDs due to anemia during pregnancy in this model as a weighted sum over the course of pregnancy stratified by these specified events.

Note that simulants who died during labor should not experience any YLDs due to anemia in the postpartum period. In other words, \(\text{DW}(\text{hgb}^\text{pp}_i) * \text{duration}^\text{pp} = 0\) for these simulants.

Hemoglobin module action point
Equation	Value	Note
I	\(\text{DW}(\text{hgb}^\text{start}_i) * \text{duration}^\text{preg}_i + \text{DW}(\text{hgb}^\text{pp}_i) * \text{duration}^\text{pp}\)	No interventions in pregnancy
II	\(\text{DW}(\text{hgb}^\text{start}_i) * T^\text{first trimester}_i + \text{DW}(\text{hgb}^\text{birth}_i) * (\text{duration}^\text{preg}_i - T^\text{first trimester}_i) + \text{DW}(\text{hgb}^\text{pp}_i) * \text{duration}^\text{pp}\)	Received IFA/MMS and/or IV iron at later pregnancy visit
III	\(\text{DW}(\text{hgb}^\text{start}_i) * T^\text{later pregnancy}_i + \text{DW}(\text{hgb}^\text{birth}_i) * (\text{duration}^\text{preg}_i - T^\text{later pregnancy}_i) + \text{DW}(\text{hgb}^\text{pp}_i) * \text{duration}^\text{pp}\)	Received IFA/MMS at first trimester visit, no IV iron
IV	\(\text{DW}(\text{hgb}^\text{start}_i) * T^\text{first trimester}_i + \text{DW}(\text{hgb}^\text{start}_i + \text{shift}^\text{IFA/MMS}) * (T^\text{later pregnancy}_i - T^\text{first trimester}_i) + \text{DW}(\text{hgb}^\text{birth}_i) * (\text{duration}^\text{preg}_i - T^\text{later pregnancy}_i) + \text{DW}(\text{hgb}^\text{pp}_i) * \text{duration}^\text{pp}\)	Received IFA/MMS at first trimester visit, IV iron at later pregnancy visit

Parameters
Parameter	Value	Source/Note
\(\text{DW}(\text{hgb})\)	Function that returns the anemia disability weight for a given hemoglobin level. Note that as written this function will need to be able to handle simulants who have died in the intrapartum component and did not progress to the postpartum period (i.e. return zero for these simulants)	See the anemia impairment document for anemia hemoglobin thresholds (use the pregnancy-specific values) and disability weights
\(\text{hgb}^\text{start}_i\)	Hemoglobin exposure at the start of pregnancy for individual simulant	Hemoglobin module
\(\text{hgb}^\text{birth}_i\)	Hemoglobin exposure at birth for individual simulant	Hemoglobin module
\(\text{hgb}^\text{pp}_i\)	Postpartum hemoglobin for individual simulant	Postpartum hemoglobin module. Note that there are some simulants who will not survive to the postpartum period and will have undefined postpartum hemoglobin.
\(\text{duration}^\text{preg}_i\)	Pregnancy duration in years for individual simulant	Pregnancy II module, note a unit conversion to years may be necessary
\(\text{duration}_\text{pp}\)	6 * 7 / 365.25	We track six weeks of postpartum anemia YLDs
\(\text{shift}_\text{IFA/MMS}\)	Effect of IFA/MMS on hemoglobin	Oral iron supplementation intervention (IFA/MMS)
\(T^\text{first trimester}_i\)	Uniform distribution between 8/52 and 12/52 (8 to 12 weeks, represented as a fraction of a year)	Randomly sample a different value for each simulant
\(T^\text{later pregnancy}_i\)	Uniform distribution between 12/52 and \(\text{duration}^\text{pregnancy}_i - 2/52\)	Randomly sample a different value for each simulant

2.4: Module Outputs 

Hemoglobin module outputs
Output	Value	Dependencies
Anemia YLDs	Point value	Simulation result

3.0 Assumptions and limitations 

We assume that first trimester ANC visits occur uniformly between 8 weeks (earliest appointments) and 12 weeks (end of first trimester) of gestation
We assume that later pregnancy ANC visits occur uniformly between 12 weeks (end of first trimester) and two weeks prior to the time of birth
We assume that interventions affect anemia YLDs at the time of administration at ANC (as according to the timed assumptions in the two prior bullets) with no additional delay
We only track anemia YLDs for six weeks postpartum

4.0 Verification and Validation Criteria 

Baseline simulated anemia YLDs should match corresponding pregnancy-specific GBD values. Run the following command to load the data from GBD 2023:

get_outputs(
    location_id=[165,179,214],
    topic='rei',
    rei_id=[206,206,207], # We also have rei_id=192 for all anemia and rei_id=432 for moderate and severe combined
    population_group_id=16,
    sex_id=2,
    year_id=2023,
    release_id=16, # release_id=33 also works
    compare_version_id=8306,
    measure_id=[3,5],
    age_group_id=[7, 8, 9, 10, 11, 12, 13, 14, 15, 24, 169]
)

Note

Make sure you have the latest version of db_queries to be able to use the population_group_id argument. To get pregnancy-specific results, the population group and the age groups need to be specified, because the default is all ages. As of the time of writing (July 2025), we can only use population_group_id=16 with get_outputs(). There were a few EPIC/COMO runs with pregnancy this GBD round, which are noted in the tracking HUB page.