Maternal health system costs of adverse birth outcomes

359 Pages·2016·2.46 MB·English

by  Jananie William

ANU COLLEGE OF BUSINESS & ECONOMICS
Maternal health system
costs of adverse birth
outcomes

Jananie William

Fellow of the Institute of Actuaries of Australia
B Actuarial Studies (Hons)
B Commerce

A thesis submitted for the degree of
Doctor of Philosophy of The Australian National University

© Copyright by Jananie William 2016
All Rights Reserved
Statement of originality
This thesis contains no material that has been accepted for the award of any other
degree or diploma in any university or other tertiary institution and, to the best of my
knowledge and belief, contains no material previously published or written by
another person, except where due reference has been made in the text. I give consent
to the final version of my thesis being made available worldwide when deposited in
the University’s Digital Repository, subject to the provisions of the Copyright Act
1968.
Jananie William

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Acknowledgements
Florence Nightingale captures my PhD research with her quote: "to understand God's
thoughts, we must study statistics for these are the measures of His purpose". I am
thankful to God and all the people He has put in my life to enable me to do just this.
This thesis is based on research conducted as part of the Australian Longitudinal
Study on Women’s Health (ALSWH) through the University of Newcastle and the
University of Queensland. I am grateful to all the participants of ALSWH for their
ongoing commitment to this project, particularly those who have endured the
hardships of an adverse birth. This research would not have been possible without
them and I am grateful for the opportunity to give them a voice. I acknowledge
Medicare Australia for providing MBS data, NSW Ministry of Health for the
administrative datasets and CHeReL for the data linkage. ALSWH is funded by the
Australian Government Department of Health and Ageing and I would also like to
thank the Australian Government, the Australian National University and the
Actuaries Institute for additional funding and support of my project.
I have been blessed with an amazing panel and work colleagues throughout this PhD
journey. Starting with my chair, Professor Michael Martin, who has provided endless
support and encouragement since I was an undergraduate, through to actuarial
qualification and a decade in the industry and finally in my entry back into academia.
I will always be grateful for his willingness to embark on this journey with me and
his expertise on every aspect of my thesis. I am also indebted to my two co-
supervisors at the University of Newcastle, Dr Catherine Chojenta and Professor
Deborah Loxton, whom I approached years ago because of my passion to work in
this area. Their openness to work with me was a major source of encouragement in
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those early days. I am particularly thankful to Dr Catherine Chojenta for her
unwavering support and important insights into some of the more complex areas of
my research. Also special thanks to Professor Deborah Loxton for helping me come
up with this topic – simply put, it was perfect for me. Professor Jim Butler also
provided valuable advice in the early stages on the health economics aspects of this
work. My colleagues at the ANU especially Associate Professor Timothy Higgins
and Professor Steven Roberts have also been wonderfully supportive during this
time. I also acknowledge Jennifer Gippel who was previously an academic in
Finance at the ANU College of Business and Economics for providing copyediting
and proofreading services, according to the guidelines laid out in the university-
endorsed national ‘Guidelines for editing research theses’.
Finally, I thank my family – the most important people in my life. First, my husband
who has been my greatest supporter for most of my life and the one who encouraged
me to start this PhD and the one who helped me finish it too. He loves me regardless
of any of it and lays down his life for me and the kids each and every day – I am
thankful for the privilege to be your wife. To my kids who have been very patient
while mummy has been busy “studying” – you are both God-given adverse birth
miracles and the reason I work in this area.
I also thank my parents and my sister who have been the driving force behind all the
successes in my life. I am forever grateful that God has blessed me with such loving
and amazing mentors. My parents have supported me my whole life and continue to
do this by caring for my children in their retirement so I can work – this thesis would
not have been possible without your selfless dedication to us. You taught me the
importance of study and hard work before I even started school. My mother
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especially, who was the best maths teacher I ever had, spent her days juggling work,
caring for kids, husband and ageing parents – and she never dropped a ball. I was
blessed to have her light guiding my path to discover my God-given gifts – my life
certainly would not be what it is today without you. I have definitely learnt from the
very best and hope that I can carry that forward to my girls and my students.
Lastly, this thesis tells the stories of mothers and their babies and the complexities of
caring for them during a vulnerable time in their lives. It is fitting therefore, that I
dedicate it to the people in my life who matter most and truly understand this
difficult walk – my mum and our precious babies.

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Table of contents
Statement of originality ............................................................................................. ii
Acknowledgements ................................................................................................... iii
List of figures ............................................................................................................. ix
List of tables............................................................................................................... xi
Abstract .................................................................................................................... xiv
1 Introduction ........................................................................................................ 1
1.1 Background of maternal health system in Australia ................................................................ 3
1.2 Adverse birth outcomes .......................................................................................................... 10
1.3 Aims ........................................................................................................................................ 11
1.4 Definitions .............................................................................................................................. 12
1.5 Thesis outline .......................................................................................................................... 14
2 Literature Review ............................................................................................ 16
2.1 Literature search .................................................................................................................... 16
2.2 Previous research results ........................................................................................................ 17
2.3 Adverse birth risk factors ........................................................................................................ 32
2.4 Conclusion .............................................................................................................................. 42
3 Methods ............................................................................................................. 44
3.1 Australian Longitudinal Study on Women’s Health ................................................................ 45
3.2 Summary of datasets for modelling ....................................................................................... 49
3.3 Hospital costing data .............................................................................................................. 52
3.4 Out-of-hospital costing data .................................................................................................. 65
3.5 Adverse birth definition by costing study ............................................................................... 75
3.6 Statistical Methods ................................................................................................................. 76
4 Results Part 1 – Hospital costing .................................................................... 87
4.1 Introduction ........................................................................................................................... 87
4.2 Methods ................................................................................................................................. 87
4.3 Results .................................................................................................................................... 94
4.4 Discussion ............................................................................................................................. 132
4.5 Conclusion ............................................................................................................................ 139
5 Results Part 2 – Out-of-hospital costing ...................................................... 141
5.1 Introduction ......................................................................................................................... 141
5.2 Methods ............................................................................................................................... 141
5.3 Results .................................................................................................................................. 145
5.4 Discussion ............................................................................................................................. 207
5.5 Conclusion ............................................................................................................................ 211
6 Discussion ........................................................................................................ 213
6.1 Evidence-informed health policy .......................................................................................... 219
6.2 Smoking status ..................................................................................................................... 220
6.3 Mental health ...................................................................................................................... 232
6.4 Summary of policy initiatives ............................................................................................... 248
6.5 Strengths .............................................................................................................................. 250
6.6 Limitations ........................................................................................................................... 252
6.7 Further research ................................................................................................................... 254
6.8 Conclusion ............................................................................................................................ 256
REFERENCES ....................................................................................................... 258
APPENDIX ............................................................................................................. 273
Appendix A ..................................................................................................................................... 273
Appendix B ..................................................................................................................................... 300
Appendix C ..................................................................................................................................... 306
Appendix D .................................................................................................................................... 310
Appendix E ..................................................................................................................................... 314
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Appendix F .....................................................................................................................................315
Appendix G .....................................................................................................................................323
Appendix H .....................................................................................................................................327
Appendix I ......................................................................................................................................331
Appendix J ......................................................................................................................................335
Appendix K .....................................................................................................................................341

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List of figures
Figure 1.1: Provision of antenatal services in Australia (2005/06) .............................. 5
Figure 1.2: Cost of disease (maternal conditions) (2004/05) ....................................... 8
Figure 1.3: Sources of maternal costs (2004/05) ......................................................... 9
Figure 1.4: Rates of adverse births in NSW (1994-2014) .......................................... 10
Figure 2.1: Mean maternal cost by gestation (Ringborg et al. 2006: Sweden, 1998-
2001) .......................................................................................................................... 22
Figure 2.2: Mean maternal cost by birthweight (Ringborg et al. 2006: Sweden 1998-
2001) .......................................................................................................................... 22
Figure 2.3: Mean maternal cost by gestation (Gilbert et al. 2003) ............................ 24
Figure 2.4: Mean maternal cost by birthweight (Gilbert et al. 2003) ........................ 25
Figure 2.5: Types of delivery in NSW (1998-2014) .................................................. 35
Figure 3.1: Timeline for hospital record data linkage ................................................ 58
Figure 3.2: Timeline of survey record data linkage ................................................... 61
Figure 4.1: Hospital costs per baby per year (2001-2012) ......................................... 96
Figure 4.2: Adverse birth rate by year (2001-2012) .................................................. 96
Figure 4.3: Mode of delivery by year (2001-2012) .................................................... 98
Figure 4.4: Total maternal hospital cost distribution (untransformed) ...................... 99
Figure 4.5: Total maternal hospital cost distribution (transformed, outlier removed)
.................................................................................................................................... 99
Figure 4.6: Private patient cost distribution ............................................................. 102
Figure 4.7: Public patient cost distribution .............................................................. 103
Figure 4.8: Public Total CART results .................................................................... 109
Figure 4.9: Public Antenatal CART results ............................................................. 110
Figure 4.10: Public Delivery CART results ............................................................. 111
Figure 4.11: Public Postnatal CART results ............................................................ 112
Figure 4.12: Private Total CART results ................................................................. 113
Figure 4.13: Private Antenatal CART results .......................................................... 114
Figure 4.14: Private Delivery CART results ............................................................ 115
Figure 4.15: Private Postnatal CART results ........................................................... 116
Figure 5.1: Adverse birth rate by year ..................................................................... 145
Figure 5.2: Adverse birth rate by age ....................................................................... 146
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Figure 5.3: Proportion of mothers aged over 30 by year ......................................... 148
Figure 5.4: Out-of-hospital costs per baby per year ................................................ 151
Figure 5.5: Number of items claimed per baby (1997-2009) .................................. 153
Figure 5.6: Proportion of babies with private health insurance ............................... 153
Figure 5.7: Change in mix of services (1997-2009) ................................................ 154
Figure 5.8: Total maternal out-of-hospital cost distributions (untransformed) ....... 156
Figure 5.9: Total maternal out-of-hospital cost distribution (transformed) ............. 157
Figure 5.10: Maternal out-of-hospital cost distribution by period (transformed) .... 157
Figure 5.11: Public vs private maternal out-of-hospital cost distribution ............... 160
Figure 5.12: Public vs private maternal out-of-hospital cost distribution by period 161
Figure 5.13: Maternal out-of-hospital costs (small) distribution by period ............. 164
Figure 5.14: Maternal out-of-hospital cost (large) distribution by period ............... 164
Figure 5.16: Public Total CART results .................................................................. 171
Figure 5.17: Public Antenatal CART results ........................................................... 172
Figure 5.18: Public Delivery CART results ............................................................. 173
Figure 5.19: Public Postnatal CART results ............................................................ 174
Figure 5.20: Private Total CART results ................................................................. 175
Figure 5.21: Private Antenatal CART results .......................................................... 176
Figure 5.22: Private Delivery CART results............................................................ 177
Figure 5.23: Private Postnatal CART results ........................................................... 178

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