Residual maternal disorders

The residual maternal disorders cause is meant to capture outcomes due to maternal disorders that are not otherwise modeled in our simulation.

Note

This modeling strategy is specific to the GBD 2023 computation hierarchy. A modeling strategy compatible with the GBD 2021 round or the GBD 2023 reporting hierarchy would exclude causes 1118 (gestational diabetes, new to GBD 2023 computation, absent in GBD reporting), 1119 (peripartum cardiomyopathy, new to GBD 2023 computation, absent in GBD 2023 reporting), and 379 (other direct maternal disorders, internal. Excludes burden due to gestational diabetes and peripartum cardiomyopathy) from the list of cause IDs to be covered in this document and replace them with cause ID 1160 (other direct maternal disorders inclusive of gestational diabetes and peripartum cardiomyopathy burden).

Disease Overview

The GBD modeling strategy for maternal disorders is discussed on the maternal disorders document. The cause model hierarchy in GBD is also included here for reference.

  • All causes (c_294) [level 0]

    • Communicable, maternal, neonatal, and nutritional diseases (c_295)

      • Maternal and neonatal disorders (c_962)

        • Maternal disorders (c_366) [level 3]

          • Maternal hemorrhage (c_367)

          • Maternal sepsis and other maternal infections (c_368)

          • Maternal hypertensive disorders (c_369)

          • Maternal obstructed labor and uterine rupture (c_370)

          • Gestational diabetes (c_1118)

          • Peripartum cardiomyopathy (c_1119)

          • Ectopic pregnancy (c_374)

          • Maternal abortion and miscarriage (c_995)

          • Other direct maternal disorders (c_379)

          • Indirect maternal deaths (c_375)

          • Late maternal deaths (c_376)

          • Maternal deaths aggravated by HIV/AIDs (c_741)

Restrictions

The following table describes any restrictions in GBD 2023 on the effects of this cause (such as being only fatal or only nonfatal), as well as restrictions on the ages and sexes to which the cause applies.

GBD 2021 Cause Restrictions

Restriction Type

Value

Notes

Male only

False

Female only

True

YLL only

False

YLD only

False

YLL age group start

10 to 14 (ID=7)

YLL age group end

50 to 54 (ID=15)

YLD age group start

10 to 14 (ID=7)

YLD age group end

50 to 54 (ID=15)

Vivarium Modeling Strategy

Scope

The goal of the residual maternal disorders model is to capture YLLs and YLDs due to maternal disorders subcauses other than those included in the abortion/miscarriage/ectopic pregnancy maternal disorders subcauses that are not otherwise modeled in the MNCNH simulation. Given that the maternal disorders subcauses specific to abortion/miscarriage/ectopic pregnancies are separately modeled (abortion/miscarriage/ectopic pregnancy maternal disorders document), we will only model residual maternal disorders among simulants who give (live or still) birth.

A list of maternal disorders subcauses and whether they are modeled elsewhere or will be covered as part of the residual maternal disorders cause modeling strategy in this document is included in the table below.

Subcause

Modeled?

Documentation link

Maternal hemorrhage (c_367)

Modeled

Maternal hemorrhage document

Maternal sepsis and other maternal infections (c_368)

Modeled

Maternal sepsis document

Maternal hypertensive disorders (c_369)

Unmodeled (will eventually be modeled in wave III)

Covered in this document (Future documentation page for hypertensive disorders)

Maternal obstructed labor and uterine rupture (c_370)

Modeled

Maternal obstructed labor and uterine rupture docs

Gestational diabetes (c_1118)

Unmodeled

Covered in this document

Peripartum cardiomyopathy (c_1119)

Unmodeled

Covered in this document

Ectopic pregnancy (c_374)

Modeled

Included in the abortion/miscarriage/ectopic pregnancy cause docs

Maternal abortion and miscarriage (c_995)

Modeled

Included in the abortion/miscarriage/ectopic pregnancy cause docs

Other direct maternal disorders (c_379)

Unmodeled

Covered in this document

Indirect maternal deaths

Unmodeled

Covered in this document

Late maternal deaths (c_376)

Unmodeled

Covered in this document

Maternal deaths aggravated by HIV/AIDS (c_741)

Unmodeled

Covered in this document

Therefore, the residual maternal disorders cause modeling strategy will include outcomes due to the causes included in the following table (along with a summary of the estimates available for each cause).

Included causes

Cause

Cause ID

YLLs

YLDs

Incidence

Note

Maternal hypertensive disorders

369

True

True

True

Note this cause will eventually be excluded from the residual maternal disorders cause model

Gestational diabetes

1118

True

True

True

Peripartum cardiomyopathy

1119

True

True

True

Indirect maternal deaths

375

True

False

False

Other direct maternal disorders

379

True

True

False

Late maternal deaths

376

True

False

False

Maternal deaths aggravated by HIV/AIDs

741

True

False

False

Summary of modeling strategy

We will model morbidity and mortality due to residual maternal disorders (inclusive of all maternal disorders subcauses that are otherwise unmodeled in our simulation) that occurs at an equal probability among all pregnancies that end in live or still birth (according to the pregnancy model document). We do not require tracking incident cases of residual maternal disorders, nor any quantities specific to subcauses included in the residual maternal disorders cause model.

Assumptions and Limitations

  • We apply morbidity due to subcauses of residual maternal disorders equally across all live/stillbirth pregnancies rather than applying the value of YLDs per incident case to a subset of incident cases

Cause Model Diagram

Conceptually, the modeling strategy for the residual maternal disorders cause can be summarized with the diagram below. All live/stillbirth pregnancies will be assigned an amount of YLDs due to residual maternal disorders at the conclusion of the intrapartum period. Some of these pregnancies will die from residual maternal disorders in accordance with the calculated fatality rate (fr) of residual maternal disorders. Regardless of whether the parent dies due to residual maternal disorders, the intrapartum period will conclude with a live or still birth outcome.

Conceptual cause model diagram

digraph RMD_decisions { rankdir = LR; start [label="start"] end [label="end"] alive [label="parent did not\ndie of residual maternal\ndisorders"] dead [label="parent died of residual\nmaternal disorders"] RMD [label="assign YLDs due to\nresidual maternal disorders"] start -> alive [label = "1 - ir"] start -> RMD [label = "ir"] RMD -> alive [label = "1 - cfr"] RMD -> dead [label = "cfr"] alive -> end [label = "1"] dead -> end [label = "1"] }

Where,

Conceptual Cause Model Diagram Parameter Definitions

State

Definition

start

Parent simulant has a live birth or stillbirth pregnancy as determined by the pregnancy model, and has already been through the pregnancy and intrapartum components (this is handled by the setup of the postpartum component)

assign YLDs due to residual maternal disorders

state in which YLDs due to residual maternal disorders are accrued

parent did not die of residual maternal disorders

Parent simulant did not die of residual maternal disorders

parent died of residual maternal disorders

Parent simulant died of residual maternal disorders

end

fr (fatality rate)

The rate of death due to residual maternal disorders among all pregnancies resulting in live or still births

While the above diagram represents the conceptual aims of the residual maternal disorders cause model, there are some convenient adjustments we can make to this diagram so that it continues to achieve the aims of our cause model while also achieving compatibility with the existing implementation of the MaternalDisorder component used in the MNCNH simulation that has been used to model other maternal disorders subcauses such as maternal sepsis. Specifically, although our modeling strategy for maternal disorders does not involve modeling incident cases, we can implement a MaternalDisorder component model as represented in the diagram below with an incidence risk (ir) value equal to 1.

Implementation-driven cause model diagram:

digraph hemorrhage_decisions { rankdir = LR; start; end; alive [label="parent did not\ndie of residual maternal\ndisorders"] dead [label="parent died of residual\nmaternal disorders"] RMD [label="affected with residual\nmaternal disorders"] start -> alive [label = "1 - ir"] start -> RMD [label = "ir"] RMD -> alive [label = "1 - cfr"] RMD -> dead [label = "cfr"] alive -> end [label = "1", style=dashed] dead -> end [label = "1", style=dashed] }

Implementation-Driven Cause Model Diagram Parameter Definitions

State

Definition

start

Parent simulant has a live birth or stillbirth pregnancy as determined by the pregnancy model, and has already been through the pregnancy and intrapartum components (this is handled by the setup of the postpartum component)

affected with residual maternal disorders

Parent is “affected with” residual maternal disorders

parent did not die of residual maternal disorders

Parent simulant did not die of residual maternal disorders

parent died of residual maternal disorders

Parent simulant died of residual maternal disorders

end

ir (incidence risk)

The probability that a pregnancy resulting in live or still birth becomes “affected with” residual maternal disorders and experiences associated morbidity

cfr (case fatality rate)

The rate of death due to residual maternal disorders among those “affected with” residual maternal disorders

Note

The concept of being “affected with” residual maternal disorders as shown in this diagram does exists only for convenience of implementation, as we do not have relevant data to inform the incidence of residual maternal disorders. Setting the ir parameter to 1 allows all pregnancies resulting in live or still birth to be subject to equal rates of morbidity and mortality due to residual maternal disorders, which is the aim of our modeling strategy for this cause.

Data Tables

Note

All quantities pulled from GBD in the following table are for a specific year, sex, age group, and location unless otherwise noted (e.g., SBR). Our simulation only includes pregnant women of reproductive age, so the sex will always be female. However, even though all of our simulants will be pregnant, we still pull each quantity for all females in a given year, age group, and location, because this is the default behavior of GBD. Since we are using the same total population in all the denominators, the person-time will cancel out in the above calculations to give us the probabilities we want.

Data values and sources

Variable

Definition

Value or source

Note

ir

the probability that a simulant whose pregnancy results in live or stillbirth is eligible for residual maternal disorders burden

1

model assumption

cfr

“case” fatality rate of residual maternal disorders

csmr / birth_rate

The value of cfr is a probabiity in [0,1]. Note that this value of the cfr (shown in the “implementation-driven cause model diagram”) is equivalent to the fr parameter shown in the “conceptual cause model diagram”

csmr

cause-specific mortality rate of residual maternal disorders

sum of cause-specific mortality rates across causes [375, 1118, 1119, 379, 376, 741, 369]

note that cause-specific mortality rates are a measure of deaths (from source=’codcorrect’) divided by population

birth_rate

birth rate (live or still)

ASFR + ASFR * SBR

Units are total births (live or still) per person-year

ASFR

Age-specific fertility rate

get_covariate_estimates: coviarate_id=13

Assume lognormal distribution of uncertainty. Units in GBD are live births per person, or equivalently, per person-year.

SBR

Stillbirth to live birth ratio

get_covariate_estimates: covariate_id=2267

Parameter is not age specific and has no draw-level uncertainty. Use mean_value as location-specific point parameter.

yld_rate

Rate of YLDs due to all residual maternal disorders subcauses among the total population

sum of cause-specific mortality rates across causes [375, 1118, 1119, 379, 376, 741, 369]. Note that only causes 379 and 369 have YLDs.

source=como

ylds_per_case

YLDs accumulated due to residual maternal disorders per case of residual maternal disorders (live/stillbirth pregnancy)

yld_rate / birth_rate

  • The ylds_per_case parameter should be applied to all simulants affected by residual maternal disorders (equivalent to all live or still birth pregnancies)

  • The cfr (case fatality rate) parameter should be applied to all simulants affected by residual maternal disorders (equivalent to all live or still birth pregnancies)

Validation Criteria

  • Deaths due to residual maternal disorders should occur among pregnancies that end in live or still births only

  • Mortality, YLL, and YLDs rate due to residual maternal disorders should match expectation in the baseline scenario

References