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Acute Mortality Related to Prescription and Illicit Drug Overdose in NZ
1998-2001
Research submitted for MSC thesis, 2003Elizabeth Morgan
Supervisor: Dr Nerida SmithSenior Lecturer in Clinical Toxicology Department of Pharmacology & Toxicology University of Otago
Drug related mortality in NZ - What has been published so far?
• Stream of literature lacks continuity – different regions over different time periods
Cairns et al (1983) – Auckland Dukes et al (1992) - Wellington
• A recent publications: • “NZ Drug Statistics” (MOH 2001)• “Surveillance of Chemical Induced Mortality in NZ”
(ESR for MOH, 2003)
Summary of the NZ Data
The information that is available suggests that:
Males are over-represented
Usually young – 20-30 yrs oldData not standardized/adjusted to population
↓ in barbiturate related deaths
TCAs common in late 1970s – early 1980s
CO deaths make up the largest proportion of deaths attributed to a single chemical/drug
The Present Study
Objectives
Examine deaths resulting acutely from prescription/illicit drugs in NZ, 1998 – 2001 using Coronial inquest data
Characteristics of the decedents & circumstances
Examine drugs involved
Identify preventable factors involved
Examine the quality & usefulness of the information available in the Coronial inquest files, for the purposes of population-based studies
Data Collection
Data collected during 2002
Case selection if death occurred between 1998 and 2001 AND if drug involvement was indicated
Deaths attributed solely to non-prescription drugs or substances not restricted by law were not included
Deaths did not have to be solely attributed to prescription/illicit drugs – additional circumstances such as disease or asphyxiation may have been named by Coroner as well
Exclusion Criteria
Death occurred as a result of long-term drug abuse (including disease as a result of drug use – HIV/AIDS)
Death as a result of withdrawal or abstinence syndromes
Drug/chemical implicated was available legally and without a prescription
Verdict – if verdict did not include any mention of drugs then case was excluded
Deaths among drug users where cause was not drug-related
Data Collected from Inquest files
File number
Date of death/date of inquest hearing
Verdict code assigned by Dept for Courts
Basic demographic data: age, gender etc. from Police Report for Coroner
Health status of the deceased
Post-mortem toxicological investigation
Cause of death – pathologist and Coroner
RESULTS
Two parts:
Describing the decedents – demographics
Post-mortem toxicology
Age & Gender
325 decedents 187 (58%) male/138 (42%) female
Aged 2-100 years – avg age 41 years Age-specific mortality data = males died younger
than females
0
5
10
15
20
25
30
35
40
45
50
0-4
5-9
10-1
4
15-1
9
20-2
4
25-2
9
30-3
4
35-3
9
40-4
4
45-4
9
50-5
4
55-5
9
60-6
4
65-6
9
70-7
4
75-7
9
80-8
485
+
age group
freq
uen
cy
Ethnicity
Ethnicity was recorded in 79% of cases Ethnicity data from PRC in 75% of these cases
0.00
1.00
2.00
3.00
4.00
male Maori male non-Maori female Maori female non-Maori
gender/ethnicity
mo
rtality
rate
per
100,0
00 p
op
ula
tio
n
Marital Status
Records available in 60% cases – Police report Of those 60% - almost three-quarters were single
(single, separated, divorced, widowed) Similar result for men & women
Employment Status
58% unemployed (S/B, unemployed, students, retired)
Proportion males > proportion of females On the whole, unemployed people were over-
represented compared to general population
Place of inquest
Auckland94 inquests
Wellington29 inquests
Christchurch36 inquests
Tauranga15 inquests
Dunedin10 inquests
New Plymouth 8 inquests
Palmerston North15 inquests
Place of Death
Own home 59%
Other 16%
Other’s residence 8%
Hospital 17%
Health Status
Very basic – decedents were defined by one of 4 categories
1. No record of mental or physical illness2. Medical history of mental illness (incl depression)3. Medical history of chronic physical illness4. Medical history of mental and chronic physical illness
Amount of information varied from file to file
People with no medical history in inquest file = included in group 1
→ undercounting of illness is likely
Health Status
No reported diagnoses of
mental or chronic physical
illness39%
32% females44% males
Reported clinically diagnosed mental
illness31%
36% females27% males
Reported chronic physical
illness18%
18% females18% males
Both mental and chronic physical illness reported
12%
14% females11% males
VerdictSuicide vs Non-Suicide
35% deaths included in this study were found to be suicide
Raw no. suicides over 4-years remained stableEven though the total no deaths each year dropped
Males outnumbered females in total… proportionally:
1998-2001 male Female
non-suicide 72% (135)54%(75)
suicide28%(52)
46%(63)
Gender, Health Status and Verdict
Health Status in cases found to be suicide:
Mental illness 46%
Physical 13%
Both 19%
Neither 22%
Health Status in cases that were not suicide
Mental illness 22%
Physical 21%
Both 9%
Neither 48%
Mental illness 22%
Physical 21%
Both 9%
Neither 48%
Gender Differences?
Females: proportions of suicide/non-suicide were similar when “health status” categories were examined separately
Males: proportions of suicide/non-suicide equal where history of mental illness was indicated
BUT in contrast to females
Only about 18% of deaths among males with chronic physical illness were suicide
Employment Status vs Suicide/Non-suicide
Proportions of suicide/non-suicide appeared to be similar for unemployed and employed decedents when “unemployment” was viewed as a whole
~ 60-65% non-suicide
Subcategories of “unemployment”:
sickness beneficiary 47% suicide
retired 42% suicide
student 38% suicideunemployed 25% suicide
Post-Mortem Toxicology Examinations
PM toxicology – ESR reports
92% cases in this study subject to tox exam 3% of these cases – report unavailable
No tox exam in remaining 8% casesprevented by decomposition, time delay etc
Of those cases subjected to testing…
3 sample sites48%
2 sample sites31%
4+ sample sites9%
1 sample sites12%
A closer look at the sample sites
• Femoral blood samples were tested in 64% of these cases
• Most of these cases a biological sample from at least 1 other site was tested
• 14% examined cases, blood was from “unknown” site. In most cases this was the only blood sample tested
• Heart blood utilised in 5% of cases – usually blood was tested from other sites too
How Many Drugs Detected PM?
3 drugs21%
2 drugs32%
1 drug21%
No testing/none detected10%
6+ drugs4%
5 drugs5%
4 drugs7%
Drugs detected most frequently
Alcohol 45%Morphine/heroin 16%Diazepam, methadone 14%Zopiclone 10%
Drugs Named by Coroner as Agents Resulting in Death
Taken from Coroners Statements
1 drug57%
2 drugs14%
3 drugs5%
4 drugs1%
5+ drugs1%
Not specified22%
Drugs most frequently involved
In cases where death was attributed to one drug:Morphine/heroin 12%Methadone 9%Dothiepin 6%Doxepin 5%Zopicolne 4%
Where death was attributed to multiple drugs:Alcohol 12%Diazepam 5%Methadone 4%Zopiclone 3%Amitriptyline 3%
Gender vs Drugs
Drugs most frequently detected PM:
Males (specific drugs named by Coroner in 145 cases) methadone>morphine>diazepam>cannabis>zopiclone
Coroner’s statements: opioids dominated deaths among males
Females (specific drugs named by Coroner in 107 cases) dothiepin>morphine>zopiclone>diazepam>amitriptyline
Coroner’s statements: TCAs dominated deaths among females
Antidepressants in general were a more prominent feature of deaths among females
Age vs Drugs
3 age groups:0 – 29 years (about 29% of studied population)
30 – 49 years (about 44% of studied population)
50+ years (about 26% of studied population)
Drugs detected post-mortem were different for each age group
0 -29 years: opioids>chemical>benzo’s & TCA’s30 – 49 years: opioids>chemical>benzo’s50+ years: chemical>TCA’s>benzo’s>opioids
Source of Drugs
Of those deaths which underwent PM toxicological examination:
Records detailing the source of the drugs detected were identified in ~41% of cases
Of the most commonly detected drugs:
OPIOIDS source identified in 33% cases; 62% illicit
morphine – 90% illicitmethadone – 60% illicit
TCAs source identified in 53% cases; 95% prescribed
BENZOssource identified in 55% cases; 75% prescribed
How complete was the data set in this study?
What proportion of ALL drug related deaths occurring in this period did I gather?
Deaths in 1998 = the most complete data set
Looked at how many inquests were processed each year versus year of death, for example of the 107 deaths occurring in 1998:
64% of inquests were processed in 1998 27% inquests were processed in 1999 9% inquests were processed in 2000 and 2001
These results are similar to ESR’s estimates (2003)
Data Completeness…
For the majority of deaths examined in this study, the inquest was completed within 2 years
Data sets for 1998 and 1999 = reasonably complete 2000 and 2001 less so
BUT…different factors may be affecting different sub-sets of the studied population, for example suicides
→ perhaps suicide investigations are completed sooner?Perhaps the number of suicides involving drugs is actually increasing?
Drug Related Mortality in the Present study…OBSERVATIONS…
SHARING MEDICINES & “SELF-MEDICATING”Noted by several Coroners
STOCKPILING OF MEDICATIONSOpioids – cancer treatment patientsBarbiturates - elderly peoplePeople being treated for illnesses known to be associated with
increased suicide risk; often had access to large amounts
INADEQUATE STORAGEMethadone – naive users, not necessarily seeking a highColchicine – teenagers, lack of knowledge about medicines
Limitations of the Present Study
1. Data collection methodsOne person collecting data – no validation
2. Comparability limitationsmany definitions of “drug-related death”
3. Completeness and quality of the data…for example – the “ethnicity” results
Completeness and quality of the data…
Study was retrospective = inherent difficulties
Disparity between the objectives of the inquest and the research objectives
inquest = focused on the individual case-by-case pop based study = requires uniform data
How can this be addressed?
How can this be addressed?
minimum dataset requirementsthese could cover the basic data needs of population based studies: demographics, circumstances of death, aspects of the inquest etc. in a way that does not impose on the Coroner
This would ensure consistency in data source etc. research would be of higher quality mortality data would be more meaningful
Where to from here?