National Anti-Drug Agency

DRUG-RELATED MORTALITY: CONCEPTS; MEASUREMENTS AND DATA CAPTURE SYSTEMS

Adenekan Oyefeso
St George's Hospital Medical School
(University of London)

OBJECTIVES

To define the term 'drug-related death'

To describe the various categories of DRD
To examine various sources of DRD data
To explore quantification of DRD
To examine various methods of enquiry of DRD
To describe the development of data capture systems

DEFINITIONS: EMCDDA

DRD can refer to deaths directly linked to acute adverse reaction, i.e., overdose.

Refer to deaths indirectly associated with drug abuse e.g., suicide, and deaths form natural causes resulting from prolonged drug abuse, AIDS, hepatitis C, etc Addiction (EMCDDA: 2000)

DEFINITION: Drug Abuse Warning Network (DAWN)

Drug-abuse death refers to death resulting from a drug used for psychic effect, dependence, or suicide, and it encompasses two other categories -
- A drug-induced death is one where the death was caused by a specific drug, through overdose.
- A drug-related death is one where the medical examiner was convinced that a specific drug was implicated but was not the sole cause (Drug Abuse Warning Network (DAWN): US Department of Health and Human Services, 2000)

DEFINITIONS: World Health Organisation (WHO)

Drug abuse-related deaths are fatal consequences of the abuse (non-medical use, misuse) of internationally controlled substances and/or of non-medical use of other substances for psychic effects

WHO: CLASSIFICATION

Acute intoxication ("overdose")
Poly-substance abuse and influence of adulterants/additives
Poisoning due to accidental exposure
Chronic intoxication
Suicides
Drug-abuse-related accidents
Drug abuse-related diseases

ICD-10 Selected Death codes

Code	Description	%
R99	Unascertained	1.3
X40-X47	Accidental poisoning	76.3
X60 -X67	Intentional self-poisoning	19.4
X70	Intentional hanging	0.6
X71	Intentional drowning	0.07
T71	Asphyxiation	0.4
W71	Accidental drowning	0.1
T07, S09.9	Multiple injury, head injuries	0.4
J18, J18.1, J18.9	Bronchopneumonia, lobar pneumonia, pneumonia	0.2
Other	Other natural causes	0.8

CORONERS IN ENGLAND AND WALES:CLASSIFICATION

Dependence on drugs
Non-dependent abuse of drugs
Accident/misadventure
Suicide
Open/undetermined
Homicide

National Programme on Substance Abuse Deaths (np-SAD)

A drug-related death case is defined as a death where any of the following criteria are met at an inquest or fatal accident inquiry
- One or more psychoactive substances directly implicated in death
- History of dependence or abuse of psychoactive drugs; OR
- Presence of Controlled Drugs at post mortem

SOURCES OF DATA

Death certificates
Coroners
Police sources
Pathologists & Toxicologists
Treatment programmes
The media
Research reports
General register
Specialist register

SOURCES OF INACCURACIES IN DRD QUANTIFICATION

Death certificates
Administration
Socio-cultural factors

NUMERATOR ERRORS

Diagnostic inaccuracies
Error in age classification
Changes in coding rules
Errors and changes in death certification
Emergence of new drugs of abuse
Emergency of new drug abuse-related conditions

DENOMINATOR ERRORS

Errors in quantifying the population at risk
Errors in demographic distribution

METHODS OF INQUIRY

Cross-sectional
Single cohort studies
Multiple cohort studies

FOCUS OF STUDIES: ADDICTS POPULATION

Mortality among opiate addicts (N = 93,000)
A 27-year study of mortality in opiate addicts (Ghodse, Oyefeso & Kilpatrick, 1998)
Average age at death = 30.6 (SIQ = 12.5)
Crude death rate = 7.7/1000 person years

FS: POPULATION OF ADDICTS

Non-therapeutic cases were about 20 times more likely to have drugs implicated in their death than therapeutic cases
Cases younger than 45 years were 6 times more likely than older cases to have drugs implicated in their death
Male addicts are 7 times more likely to die prematurely than the general population male
Female addicts are 10 times more likely to die prematurely

FS: SPECIFIC CONDITIONS

Suicide (Oyefeso et al., 1999)

Rates: Male = 69/100,000 person years
Female = 44.8/100,000 py

15-24 38.2/100,000
25-34 83.2/100,000
35-54 75.3/100,000

FS: SPECIFIC CONDITIONS

Excess risk of suicide
Male 3.1
Female 5.5

Methods of suicide
Drug overdose 45%
Hanging 31%
CO poisoning 11%
Gunshot 3.5 %
Other 9.5%

FS: SPECIAL POPULATION

Mortality of teenage addicts
(Oyefeso et al., 1999)

Teenage-specific mortality rates:
Male = 1.3/1000 person-years
Female = 0.9/1000 person years

Excess risk of teenage death = 12.3 (95%CI = 9.6, 15.5)
Male 10.7 (95%CI = 8.0, 14.1)
Female 21.2 (95% CI = 12.6, 33.5)

FS: SPECIAL POPULATION

Causes of death

Drug overdose 68.6%
Suicide 11.4%
Complications and
Natural causes 20.0%

FS: DRUG-SPECIFIC FATALITY

Review of deaths related to taking ecstasy, England & Wales, 1997-2000 (N = 81)
(Schifano et al, 2002)

Gender: Male 81%
Female 19%
Average age: 27 years (16-50)
Employed: 46%
Known to services 57%

FS: DRUG-SPECIFIC FATALITY

Causes of death
- Polysubstance poisoning 62%
- Only MDMA poisoning 7%
- Other 31%

Place of death
- Private residence 49%
- Hospital 31%
- Pub or club 2%
- Others 17%

Day of death - Saturday +Sunday 56%

REPORTING PRINCIPLES

Specify definitions
Define clear categories
Ensure validity of data sources and limitations
Define type of studies from which data was generated
Define scope of enquiry
Describe the data capture system

DATA CAPTURE SYSTEMS

General Registers
Specialist registers

What is surveillance?

"ongoing systematic collection, analysis, and interpretation of outcome-specific health data, closely integrated with the timely dissemination of these data to those responsible for preventing and controlling disease or injury"

(Thacker & Stroup, 1998).

Why is drug-related mortality surveillance necessary?

Detect immediate changes e.g. newly emerging drugs responsible for overdose
Disseminate findings, bi-annually/annually to facilitate research priority-setting; and estimate magnitude of problem
Maintain archival information for noting the pattern of drug-related deaths over time and correlating this with government and local policies/ national clinical practices to evaluate effectiveness

Why is drug-related mortality surveillance necessary

Monitor geographical location of a reported incident is of equal value
Develop risk profiles by obtaining information on the 'person' in terms of their characteristics e.g. gender, ethnicity, history of known substance misuse, prescription history

Components of drug-related mortality surveillance

Consult widely

Establishment of goals/purposes
Develop case definitions
Select appropriate personnel
Develop and/or acquire tools and clearances for collection, analysis, and dissemination
Implement the surveillance system
Evaluate surveillance activities

Establishment of Goal/Purpose

The objectives are to

Collect and collate data on psychoactive substance-related mortality;
Examine trends in these data;
Provide relevant commentary on the prevention of substance related deaths whether caused accidentally or intentionally from data analysis; and
Ensure that dissemination of such information was concise and prompt.

Case definition

Review the various definitions of drug-related deaths.
Identify your criteria for caseness
Review your criteria with experts
Pilot the criteria for robustness
Publish the criteria for caseness

Appropriate Personnel

Define key personnel requirements to include the following competencies

Clinical competency
Epidemiological and biostatistics
Database administration and management
Networking and collaboration
Writing and editorial skills
Web publishing
Drug abuse policy

Acquisition of tools, and clearance for collection, analysis and dissemination

Consult with data providers and seek their cooperation
Develop and agree data collection tools with data providers
Develop a database in a readily accessible electronic format to facilitate understanding further studies of predictors, trends and patterns of drug-related deaths
Develop validation codes to minimise error in data entry
Establish ethical guidelines on data access, data protection and confidentiality

Implementation

Inform the data providers of your start date, possibly have a launch
Engage policy makers in your programme and seek their support
Provide resources to facilitate data providers' compliance
Provide prompt and regular feedback to data providers
Publish the findings of the surveillance periodically
Disseminate your reports widely

Evaluation

Request regular feedback from data providers
Conduct regular internal audits of data capture and coding accuracy
Present procedures and findings at conferences, workshops and special forums