The Impact of Obesity on
Maternity Care and Costs
Paddy Gillespie, John Cullinan, Ciaran O’Neill, Fidelma Dunne
Health Economics and Policy Analysis Group
& Discipline of Economics, NUI Galway
http://www.nuigalway.ie/health-economics/
NUIG Conference on Obesity, 17 January 2014
The Impact of Obesity on Maternity Care and Costs
Key Message
• Obesity in pregnancy is associated with significantly
higher levels of caesarean section, neonatal intensive
care unit admission, and maternity care costs.
The Impact of Obesity on Maternity Care and Costs
Background: ATLANTIC Diabetes in Pregnancy (DIP) Network
The Impact of Obesity on Maternity Care and Costs
Background: ATLANTIC Diabetes in Pregnancy (DIP) Network
• Established 2005
• 5 regional hospitals in the
west of Ireland with a
catchment population of
approximately 500,000.
• Data for the 58% of all
women who participated
in GDM screening were
available for analysis.
• Data on a range of clinical
characteristics, pregnancy
outcomes, and healthcare
utilisation.
The Impact of Obesity on Maternity Care and Costs
Methodology (1): Study Sample
N
Variable
4372
Mean(SD) / %
Normal Weight, %
39
Overweight, %
36
Obese, %
25
Gestational Diabetes Mellitus, %
8
Age in Years, mean (SD)
35 (5.3)
Ethnic Group: White, %
92
Primiparous, %
44
Body Mass Index (BMI) – Mean (SD)
27 (5.3)
Family History of Diabetes , %
36
Previous Miscarriage, %
26
The Impact of Obesity on Maternity Care and Costs
Methodology (2): Statistical Analysis
• Multivariate regression to explore the effect of a range of independent
variables on three outcome or dependent variables:
1.
Mode of delivery:
– Four category variable identifying the nature of the delivery:
1.
2.
3.
4.
Normal delivery
Assisted delivery (i.e. forceps and/or ventose)
Elective caesarean section
Emergency caesarean section delivery
2.
Neonatal intensive care unit admission:
– Binary variable identifying whether or not an infant was admitted to
the neonatal intensive care unit.
3.
Costs of care:
– Unit costs in 2009 € prices, estimated based on the Health Service
Executive Casemix database, were applied to cost resource activity for
delivery care and neonatal care.
The Impact of Obesity on Maternity Care and Costs
Methodology (3): Statistical Analysis
• Main independent variable in all analyses was obesity status:
– Body mass index (BMI) measured at the first obstetrical visit:
• Normal: 20-25 kg/m2
• Overweight: 25 – 30 kg/m2
• Obese: >30 kg/m2)
• Other independent variables included:
–
–
–
–
–
–
–
Age category (<30, 30-40, or >40 years)
Ethnicity (caucasian/white or other)
Primiparous
GDM
Family history of diabetes
Previous miscarriage
Delivery week category (>=39, 36-39, <36 weeks)
The Impact of Obesity on Maternity Care and Costs
Results
Variable/Model
Model 1
Mode of Delivery
Odds Ratios(SE)
Model 2
Neonatal
Admission
Model 3
Maternity
Cost
Normal
Delivery
Assisted
Normal
Delivery
Elective
Caesarean
Section
Emergency
Caesarean
Section
Odds Ratios (SE)
Coefficient (SE)
(% change in €)
Normal Weight
(base)
(base)
(base)
(base)
(base)
(base)
Overweight
(base)
0.92 (0.10)
1.79 (0.31)**
1.53 (0.25)*
1.01 (0.14)
0.05 (0.03)
Obese
(base)
0.81 (0.12)
2.67 (0.48)**
2.56 (0.45)**
1.40 (0.20)*
0.21 (0.03)**
Statistical Significance: * p-value < 0.05; ** p-value <0.01
• Model 1 - Multinomial logistic regression
• Model 2 - Logistic regression:
• Model 3 - Generalized linear regression model (Gamma variance function ,log-link function)
• All models estimated controlling for Age, Ethnicity , Parity, GDM status, Family history of diabetes,
Previous miscarriage, Delivery week.
The Impact of Obesity on Maternity Care and Costs
Conclusions
• We find that:
– Obesity in pregnancy is associated with significantly higher levels
of caesarean section, neonatal intensive care unit admission, and
maternity care costs.
– Other variables significantly associated with variations in:
• Assisted normal delivery: Age, Parity and Delivery week.
• Elective caesarean section: Age, Family history and Delivery week.
• Emergency caesarean section: GDM, Age, Parity and Delivery week.
• Costs of Care: GDM, Age, Parity and Delivery week.
• Limitations and future work
•
•
•
Selection bias issue
Omitted variables: e.g. previous caesarean section
Underestimate costs : what of costs prior and post maternity care?
Thank you for your attention