nsw bureau of crime statistics and research did the heroin shortage increase amphetamine use in nsw?...
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NSW Bureau of Crime Statistics and Research
Did the heroin shortage increase
amphetamine use in NSW?Lucy Snowball, Steve Moffatt, Don Weatherburn
and Melissa Burgess
Background
• Dec 2000/Jan 2001: significant reduction in heroin supply, purity and increase in cost– Onset of ‘heroin shortage’
• Concerns about drug substitution– Cocaine and amphetamines (ATS)
• Fears about ATS– Effects (psychosis, violence, depression)
– Australian treatment methods centred around heroin addiction
Previous studies
• Previous research has found mixed results:– Darke et al (2006) found a drop in ATS use– Maher (2007), Longo (2004) found an increase
• Previous research has been hampered by unrepresentative samples and low sample sizes
Current study
• Aim: To determine whether there was evidence of a switch from heroin to ATS as a result of the heroin shortage
• Data: use/possess series for narcotics and amphetamines, Jan 1995 – Sept 2007
• Method: Vector auto regression (VAR) and ARIMA modelling
Methodological issues
• Narcotics use/possess as a proxy for heroin?
• Are use/possess arrests a good indicator for drug use?
Emergency admissions vs. Arrests rates: Heroin
Figure 1a: Quarterly heroin-related hospital presentations and use/possess narcotics arrests, March qtr 1998 - March qtr 2007
0
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1000
Mar
-98
Sep
-98
Mar
-99
Sep
-99
Mar
-00
Sep
-00
Mar
-01
Sep
-01
Mar
-02
Sep
-02
Mar
-03
Sep
-03
Mar
-04
Sep
-04
Mar
-05
Sep
-05
Mar
-06
Sep
-06
Mar
-07
Hospital admissions (Heroin)
Use/possess incidents (Narcotics)
Emergency admissions vs. Arrest rates: ATS
Figure 1b: Quarterly amphetamine-related hospital prsentations and amphetamines use/possess arrests, March qtr 1998 - March qt 2007
0
20
40
60
80
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120
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180
Mar
-199
8
Sep
-199
8
Mar
-199
9
Sep
-199
9
Mar
-200
0
Sep
-200
0
Mar
-200
1
Sep
-200
1
Mar
-200
2
Sep
-200
2
Mar
-200
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Sep
-200
3
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-200
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Sep
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-200
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-200
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Sep
-200
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Mar
-200
7
Ho
spit
al a
dm
issi
on
s
0
100
200
300
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800
Use
/po
sses
s ar
rest
s
Hospital admissions(amphetamines)
Use/possess arrests(amphetamines)
Methodological issues
• Narcotics use/possess as a proxy for heroin?
• Are use/possess arrests a good indicator for drug use?
• When did the heroin shortage start?
Table 2: Monthly use/possess arrest rates for emphatamines and narcotics, Janurary 1995 - September 2007
0
50
100
150
200
250
300
350
400
Jan-
95
Jul-9
5
Jan-
96
Jul-9
6
Jan-
97
Jul-9
7
Jan-
98
Jul-9
8
Jan-
99
Jul-9
9
Jan-
00
Jul-0
0
Jan-
01
Jul-0
1
Jan-
02
Jul-0
2
Jan-
03
Jul-0
3
Jan-
04
Jul-0
4
Jan-
05
Jul-0
5
Jan-
06
Jul-0
6
Jan-
07
Jul-0
7
Use/possess narcotics
Use/possess amphetamines
Amphetamines and narcotics use/possess
Correlations, use/possess amphetamines and narcotics
0
50
100
150
200
250
300
350
400
1995
/Jan
1995
/Jun
1995
/Nov
1996
/Apr
1996
/Sep
1997
/Feb
1997
/Jul
1997
/Dec
1998
/May
1998
/Oct
1999
/Mar
1999
/Aug
2000
/Jan
2000
/Jun
2000
/Nov
2001
/Apr
2001
/Sep
2002
/Feb
2002
/Jul
2002
/Dec
2003
/May
2003
/Oct
2004
/Mar
2004
/Aug
2005
/Jan
2005
/Jun
2005
/Nov
2006
/Apr
2006
/Sep
2007
/Feb
2007
/Jul
2007
/Dec
Possession and/oruse of narcoticsPossession and/oruse of amphetamines
r = -0.39
r = 0.80
r= -0.58
r = -0.38
r = -0.38
Correlations
Methodological issues
• Narcotics use/possess as a proxy for heroin?
• Are use/possess arrests a good indicator for drug use?
• When did the heroin shortage start?
• Is narcotics use centred around different locations than ATS use?
Map of narcotics arrests
Map of amphetamine arrests
Types of analysis• Vector autoregression
– Whole of NSW
– High use LGAs: Sydney, Marrickville, Bankstown, Liverpool, Fairfield, Wollongong, Newcastle
• ARIMA regression– Entire time period (Jan 1995 – Sept 2007)
– After first drop (Mar 1999 – Sept 2007)
– After onset of ‘heroin shortage’ (Dec 2000 – Sept 2007)
– Period of heroin drop (Mar 1999 – Apr 2002)
VAR Results – High use LGAs
Lag Coefficient (with standard error) p-val Coefficient (with standard error) p-val1 0.012 (0.091) 0.894 -0.033 (0.076) 0.6642 -0.012 (0.108) 0.914 -0.006 (0.080) 0.9413 -0.154 (0.112) 0.168 -0.086 (0.078) 0.2704 -0.010 (0.109) 0.358 0.088 (0.079) 0.2615 0.098 (0.092) 0.289 0.056 (0.075) 0.456
Narcotics model Amphetamines model
VAR Results – NSW Lag Coefficient (with standard error) p-val Coefficient (with standard error) p-val1 -0.076 (0.090) 0.398 -0.092 (0.076) 0.2232 0.017 (0.107) 0.870 0.029 (0.080) 0.7143 -0.244 (0.107) 0.023 0.005 (0.077) 0.9494 -0.097 (0.109) 0.377 -0.075 (0.077) 0.3325 0.199 (0.094) 0.035 0.028 (0.072) 0.694
R-squared = 0.348
Narcotics model Amphetamines model
R-squared = 0.268
Results - ARIMAModel 1
Jan 1995 - Sep 2007Model 2
Mar 1999 - Sep 2007Narcotics 0.079 (0.090) 0.055 (0.105)Constant -0.368 (1.354) -2.470 (1.705)AR(1) -0.367 (0.055)* -0.384 (0.061)*AR(3) -0.136 (0.069)* -0.158 (0.080)*
Model 3 Dec 2000 - Sep 2007
Model 4 Dec 2000 - Apr 2002
Narcotics 0.020 (0.086) 0.105 (0.264)Constant -1.793 (1.833) -6.366 (4.601)AR(1) -0.264 (0.106)* -0.366 (0.149)*AR(3) - -
Summary and discussion
• No evidence of drug substitution was found
• Although ATS use increased after the ‘shortage’, this is part of a long term increasing trend
Amphetamines use/possess, 1995 – 2007
y = 1.0394x + 57.049R2 = 0.7579
0
50
100
150
200
250
300
350
Jan95
Jul95
Jan96
Jul96
Jan97
Jul97
Jan98
Jul98
Jan99
Jul99
Jan00
Jul00
Jan01
Jul01
Jan02
Jul02
Jan03
Jul03
Jan04
Jul04
Jan05
Jul05
Jan06
Jul06
Jan07
Jul07
Possession and/or use of amphetamines, NSW Linear (Possession and/or use of amphetamines, NSW)
Reported incidents
Summary and discussion
• No evidence of drug substitution was found• Although ATS use increased after the
‘shortage’, this is part of a long term increasing trend
• Rather than focusing on heroin and supply reduction policies, need to focus on ATS use and how this can be reduced
• Note that these results hold for NSW only