the effect of alcohol outlets and sales on alcohol related injuries presenting at emergency

448 Pages·2014·3.77 MB·English

by  Michelle Hobday

Faculty of Health Sciences
National Drug Research Institute

The Effect of Alcohol Outlets and Sales on Alcohol-Related Injuries
Presenting at Emergency Departments in Perth, Australia, from 2002 to 2010

Michelle Bridget Hobday

This thesis is presented for the Degree of
Doctor of Philosophy
of
Curtin University

March 2014
Statement
To the best of my knowledge and belief this thesis contains no material previously
published by any other person except where due acknowledgment has been made. This thesis
contains no material which has been accepted for the award of any other degree or diploma in
any university.

Michelle Bridget Hobday
Date:

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Acknowledgements
Professor Tanya Chikritizhs, my supervisor: thank you for sharing your knowledge and
experience of alcohol epidemiology with me, for guiding and pushing me to improve and for
demanding high standards from me.
Professor Lynn Meuleners, my co-supervisor: thank you for your advice on how to approach the
PhD process, input on the structure and content of my thesis, and emotional support through the
rollercoaster ride that is a PhD.
Dr Wenbin Liang, my co-supervisor: thank you, Ben, for your patience in helping me navigate
my way through Stata and panel models, and focusing me on the details of my methods.
The support and partnership of the Drug and Alcohol Office of Western Australia has been
invaluable in this project, especially in helping to access a variety of data quickly. Special thanks
go to Gary Kirby, my associate supervisor, and Leesa Whittaker, Coordinator Legislation &
Projects, Alcohol programs.
Thank you to the staff at the Western Australian Data Linkage Branch and the Emergency
Department Data Collection, particularly Alex Godfrey, Project Officer, and Michele Russell,
Manager Non Admitted Data Collections.
Dr Sue Carruthers, the chair of my thesis committee: thank you for efficiently managing the
background administration and being available for me.
Thank you also to Curtin University, which has provided me with scholarships which made
studying possible and supplied training and other support structures which made the process
easier.
Will Gilmore, research fellow at NDRI: thanks for your help getting me started in ArcGIS,
sorting out difficulties with the sales data and being a sounding board for my ideas about spatial
statistics and GIS.
Paul Catalano, independent consultant to NDRI, thank you for advising me on various aspects of
ArcGIS.
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Thank you to the administrative staff at NDRI for your support and friendliness. Particular
thanks go to Jo Hawkins for incredibly quickly and efficiently handling all the financial aspects
of my PhD.
Thank you to Paul Jones, Computer Systems Officer at NDRI, for patiently putting up with my
computer problems and mistakes, and helping me through them.
Thanks to Dr Yun Zhao, senior lecturer in biostatistics in the School of Public Health, for
answering my questions on several occasions, as I strove to ‘understand’ biostatistics.
To Narelle Mullan who discussed some of the issues I had with GIS and analysis of the spatial
data, and directed me to other helpful people in this field.
Thank you to Dr Brett Adams who demystified MATLAB.
To Dr Stephen Knight, my Master’s supervisor at the Department of Public Health Medicine, the
University of KwaZulu-Natal, South Africa: thank you, Stephen, for believing in me and
encouraging me to pursue my interest in epidemiology. Had it not been for you, I would
probably still be a physiotherapist.
Thank you to my long-suffering friends who kindly asked how my degree was going for more
than three years: I will be drinking coffee with you all soon!
For my parents, who have supported me both physically and emotionally, and have always had
faith in my abilities.
To my husband, Nigel, and my two girls: you have put up with grumpiness, absent-mindedness,
occasional euphoria and sometimes misery for three and a half years. Thank you for giving me
the space to do this PhD, Nigel, and living through it. And to my beloved Emily and Leah: Moo
loves you very much and looks forward to being able to spend more time with you.
To my God: for giving me the opportunity to undertake this life-changing experience and the
persistence to stick with it.

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Abstract:
Introduction: Many studies have examined the effects of alcohol outlet density on
alcohol-related harms including assault and road crashes. There is, however, a paucity of
research establishing the effects of alcohol sales and differences between alcohol outlets on
alcohol-related harms, especially on injury cases presenting at Emergency Departments (EDs).
This study aimed to examine the effects of these outlets and wholesale alcohol purchases on
alcohol-related injuries presenting at EDs.
Methods: A surrogate measure of alcohol-related injuries was verified using each year
of ED data, and applied to the dataset. The relationship between place of residence and place of
alcohol purchase was verified by undertaking an online panel survey. Volumes of alcohol sales
for each postcode and suburb were obtained from the Drug and Alcohol Office, Government of
Western Australia. Using injury and outlet data at postcode-level, circular buffer zones were
created around the centre of postcodes in which injury cases resided. Outlets were then coded
according to their location within multiple buffers. Demographic and socio-economic
characteristics of the postcode populations were utilised. Distance from the Perth CBD was a
further predictor incorporated in the analysis. Physical alcohol availability was measured using:
number of outlets by licence type; trading hours; and wholesale purchases of beer, wine and
spirits (a proxy for retail sales). Using negative binomial regression with random effects, models
were created to describe the relationship between the indicators of alcohol availability and
alcohol-related ED injury.
Results: Analyses showed that higher pure alcohol sales per off-premise outlet and
higher counts of on-premise outlets were significantly associated with higher numbers of
alcohol-related injuries presenting at EDs. These results were demonstrated at both postcode-
and suburb-level. The strength of the association varied depending on the size of the buffer zone
used, with the strongest associations evident when total outlets and sales in postcodes and
suburbs were used. Postcodes and suburbs with higher proportions of unemployed residents and
residents of Indigenous origin were also significantly associated with higher numbers of alcohol-
related injuries.
Conclusion: With off-premise outlets, volume of alcohol sales was a more important
predictor than the absolute number of bottle shops. However, the count of on-premise outlets
(and potentially the clustering of these outlets) was of more significance than the volume of
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sales, pointing to the negative effects which on-premise outlets have on the neighbourhoods
surrounding them. The results suggested that both off- and on-premise outlets were associated
with alcohol-related injury but that alcohol control policies need to take cognisance of their
different mechanisms of action to effectively reduce harm.
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Table of Contents
Acknowledgements ...................................................................................................................................... iii
Abstract: ........................................................................................................................................................ v
List of Tables ................................................................................................................................................ x
List of Figures ........................................................................................................................................... xxv
List of Maps ............................................................................................................................................. xxvi
1 Introduction ........................................................................................................................................... 1
1.1 Rationale ...................................................................................................................................... 2
1.2 The study area: Perth Metropolitan Area ................................................................................ 3
1.3 Research aims and objectives..................................................................................................... 4
1.4 Significance .................................................................................................................................. 4
1.5 Overview of the Thesis ................................................................................................................ 5
2 A brief history of alcohol consumption and control measures in Australia .......................................... 6
2.1 The early history of alcohol consumption and control policies in Australia ......................... 6
2.2 Loosening of alcohol controls ..................................................................................................... 7
2.3 Recent developments in regulating the physical availability of alcohol ................................. 8
2.4 The way forward ....................................................................................................................... 18
3 Literature review ................................................................................................................................. 20
3.1 Search strategy .......................................................................................................................... 20
3.2 Alcohol and injury .................................................................................................................... 21
3.3 Alcohol-related presentations at the ED ................................................................................. 22
3.4 Measuring alcohol-involvement in patients presenting at EDs ............................................. 29
3.5 The availability of alcohol and its relationship to alcohol-related harms ............................ 37
3.6 Evidence for associations between alcohol availability and harm: trading hours,
minimum legal drinking age, government monopolies and price ..................................................... 44
3.7 Evidence for associations between alcohol outlet density and harm .................................... 49
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3.8 Evidence for associations between alcohol sales and harm ................................................... 83
3.9 Methodological issues relating to analysis of data in the current project ............................ 88
3.10 Summary .................................................................................................................................... 99
4 Hypotheses, design overview and methodology ............................................................................... 100
4.1 Hypotheses ............................................................................................................................... 100
4.2 The study area and population .............................................................................................. 100
4.3 Design overview ....................................................................................................................... 101
4.4 Phase One ................................................................................................................................ 101
4.5 Phase two: online survey ........................................................................................................ 107
4.6 Phase Three ............................................................................................................................. 111
4.7 Phase four ................................................................................................................................ 119
4.8 Ethical considerations ............................................................................................................. 124
5 Results for Phase One: ED Data ....................................................................................................... 127
5.1 Overview of ED datasets......................................................................................................... 127
5.2 Incidence Rate Ratios for all injuries .................................................................................... 129
5.3 Surrogate measure validation ................................................................................................ 130
5.4 Summary .................................................................................................................................. 139
6 Results for Phase Two: Online Survey ............................................................................................. 140
6.1 The Pilot study ......................................................................................................................... 140
6.2 Online survey ........................................................................................................................... 144
6.3 Discussion and summary ........................................................................................................ 156
7 Results from Phases Three and Four: Collation of Alcohol Availability Data and Final
Model Development .................................................................................................................................. 158
7.1 Description of alcohol availability data ................................................................................. 158
7.2 Choice of ABS demographic and socio-economic variables ................................................ 164
7.3 Statistical model development................................................................................................ 166
7.4 Summary .................................................................................................................................. 224
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8 Summary and Discussion .................................................................................................................. 225
8.1 Summary of findings as they relate to hypotheses ............................................................... 225
8.2 Strengths and limitations of the study ................................................................................... 230
8.3 Discussion................................................................................................................................. 238
8.4 Recommendations ................................................................................................................... 255
8.5 Conclusion ............................................................................................................................... 257
9 References ......................................................................................................................................... 258
10 Appendices ........................................................................................................................................ 282
10.1 Ethics permission .................................................................................................................... 282
10.2 Extraction form for the Data Linkage Branch ..................................................................... 285
10.3 Tables showing numbers for validation of surrogates ......................................................... 289
10.4 Pilot questionnaire .................................................................................................................. 299
10.5 Pilot study reliability test results ........................................................................................... 306
10.6 Sample size calculation for online survey ............................................................................. 308
10.7 Sample quotas for online survey by Pureprofile .................................................................. 309
10.8 Final questionnaire ................................................................................................................. 310
10.9 Conversion factors used to calculate volumes of pure alcohol ............................................ 325
10.10 Additional models for Phase four .......................................................................................... 326

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List of Tables
Table 2.1: An overview of the current liquor licensing legislation in the states and territories in
Australia ....................................................................................................................................... 13
Table 5.1: Summary table of demographic features of all ED, wholly alcohol-attributable and all
injury cases presenting at Perth EDs from 1 July 2002 to 30 June 2010 ................................... 127
Table 5.2: Summary table of time periods of all ED, wholly alcohol-attributable and all injury
cases presenting at Perth EDs from 1 July 2002 to 30 June 2010 .............................................. 128
Table 5.3: Negative binomial regression model of all injuries presenting at Perth EDs between 1
July 2002 and 30 June 2010 ....................................................................................................... 129
Table 5.4: Comparison of candidate surrogate measure for Emergency Department data, using
Perth, South Australian and international data from 2002 to 2010 ............................................ 132
Table 5.5: Pearson’s Correlation Coefficient tests comparing various categories of ED
presentations at Perth ED between 1 July 2002 and 30 June 2010 ............................................ 133
Table 5.6: Comparison of injury cases across time periods with low proportions of alcohol-
related cases, in Perth EDs from 1 July 2002 to 30 June 2010 .................................................. 136
Table 5.7: Breakdown of demographic characteristics and triage categories of injury cases by
surrogate measures, presenting at Perth EDs between from 1 July 2002 to 30 June 2010 ........ 139
Table 6.1: Distribution of age categories in the national online survey in Australian capital cities1
in 2012 ....................................................................................................................................... 144
Table 6.2: Demographic and socio-economic characteristics of participants in the national online
survey in Australian capital cities1 in 2012 ................................................................................ 145
Table 6.3: Comparison of the frequency of drinking between participants of the 2007 National
Drug Strategy Surveys and the 2012 online survey in Australia ............................................... 146
Table 6.4: Comparison of the frequency of drinking between participants of the 2010 National
Drug Strategy Surveys and the 2012 online survey in Australia ............................................... 147
Table 6.5: Comparison of the main type of alcohol usually consumed by participants of the 2010
National Drug Strategy Survey and the 2012 online survey in Australia .................................. 147
Table 6.6: Mode of transport used by online survey participants to purchase alcohol, in
Australian capital cities in 2012 ................................................................................................. 148
Table 6.7: Factors affecting choice of location for purchasing alcohol by participants of the
online survey, in Australian capital cities in 2012 ..................................................................... 149
Table 6.8: Distance that online survey participants were prepared to travel to purchase alcohol at
a bottle shop, by socio-demographic factors, in Australian capital cities in 2012 ..................... 150
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