Table 1 Overview of reviewed studies

Bertilone

2015

Australia

Case-control study

Participant group n=350

Historical control group n=350

Contemporary control group n=350

Aboriginal Maternity Group Practice Program (AMGPP)

Indigenous

Organisational

Preterm birth and birthweight

Preterm birth: aOR 0.75 CI (0.58-0.95) intervention vs control

Low birthweight: aOR 0.83 CI (0.66-1.07) intervention) vs control

(NOTE: each outcome is adjusted for pregnancy complications, smoking and previous caesarean delivery)

Byrskog

2020

Sweden

Retrospective cohort study

Migrant women with intervention n=880

Migrant women without intervention n=16789

Swedish-born women n=129

Community-based bilingual doulas

CALD

Interpersonal

Preterm birth and birthweight

Preterm: OR 0.41 CI (0.26 – 0.65) intervention vs control

Low birthweight:

0.55 CI (0.37 – 0.81) intervention vs control

Coughlin

2013

USA

Retrospective cohort study

Cohort n=872

Comparison group n=3277

Healthy Start home visiting program, community-driven and population specific interventions

Indigenous

Community

Preterm birth and birthweight

Preterm: OR 0.94 CI (0.68, 1.30) intervention vs control. For medically underserved areas: aOR 0.62 (0.31, 1.23) intervention vs control. 

Low birthweight:  aOR 0.91 CI (0.61 – 1.36) intervention vs control. For medically underserved areas: aOR 0.37 CI (0.14 – 0.96) intervention vs control.

(NOTES:

aOR for Preterm are adjusted for number of maternal risk factors and delivery payment source. 

aOR for low birthweight are adjusted for number of maternal risk factors, delivery payment source, tobacco use during pregnancy, and mother’s age)

Hartz

2019

Australia

Comparative Cohort study

Cohort with intervention n=505

Comparison group n=201

Malabar Midwifery Service

Indigenous

Organisational

Preterm birth and birthweight

Preterm: aOR 2.2 CI (0.96-4.97) intervention vs control.

Low birthweight:aOR 3.6 CI (1.02-12.9) intervention vs control.

(NOTE: aOR reported for each outcome are adjusted for nulliparity, parity, obstetric and medical risk at the onset of labour, psychosocial risk at the onset of labour, smoking

2nd half pregnancy, preterm, SEIFA, augmented & induction combined)

Kildea

2019

Australia

Comparative Cohort study

Cohort n=461

Comparison n=563

Birthing on Country

Indigenous

Organisational

Preterm birth

Preterm: OR 0.50 CI (0.31 – 0.83) intervention vs standard care.

Kildea

2016

Australia

Comparative Cohort Study

Retrospective cohort n=412

Prospective cohort n=310

Midwifery Group Practice (MGP)

Indigenous

Organisational

Preterm birth and birthweight

Preterm: P Value 0.906 Low birthweight: P Value 0.122

Kildea

2012

Australia

Mixed-Methods Cohort n=367

Comparison n=414

The Murri Antenatal Clinic

Indigenous

Organisational

Preterm birth

Preterm: aOR

0.92 CI (0.59 – 1.43) 

NOTE: Adjusted for maternal age, parity, body mass index, smoking, medical complications (gestational diabetes, antepartum haemorrhage, pregnancy induced hypertension, asthma) and socio-economic status as measured by the Socio-Economic Indexes of Areas.)

O’Connell

2009

USA

Comparative Cohort

Cohort n=182

Comparison n=182

The MOMmobile

CALD

Organisational

Preterm birth and birthweight

ORs from matched sample:

Preterm OR 9.12 CI (5.66 - 15.49) intervention vs control. 

Low birthweight:

OR 10.88 CI (6.51 - 19.45) intervention vs control. 

Swartz

2017

USA

Observational Cohort study

Emergency Medicaid n = 35182

Emergency Medicaid Plus n = 12510

Medicaid n=166054

Staggered rollout of Emergency Medicaid Plus vs Regular Medicaid pregnancies

CALD

Policy

Preterm birth and birthweight

Difference in difference*:

Low birthweight:

1.84 (-6.74 to 10.42)

Triple DID 4.80 (0.30 to 9.30)

Preterm:

DID 2.46 (-8.05 to 12.97)

Triple DID 10.12 (3.15 to 17.09)

NOTE*: Difference in difference analysis method uses data from treatment and control groups to obtain an appropriate counterfactual to estimate a causal effect. Raw data and odds ratio was not available for this study.