A 10-year Prospective Study of Mortality among Norwegian Drug Abusers after
Seeking Treatment
Edle Ravndal
1*
, Grethe Lauritzen
2
and Michael Gossop
3
1
University of Oslo, Norwegian Centre for Addiction Research (SERAF), Ullevål Hospital, 0315 Oslo, Norway
2
Norwegian Institute for Alcohol and Drug Research (SIRUS), Øvre Slottsgt. 2B, 0157 Oslo, Norway
3
National Addiction Centre, National Addiction Centre, 4 Windsor Walk, London SE5 8BB, UK
*
Corresponding author: Edle Ravndal, University of Oslo, Norwegian Centre for Addiction Research (SERAF), P.O. Box 1039 Blindern, 0315 Oslo, Norway, Tel: 47 23
36 89 74; Fax: 47 23 36 89 86; E-mail: edle.ravndal@medisin.uio.no
Received date: Feb 26, 2015; Accepted date: Mar 20, 2015; Published date: Mar 25, 2015
Copyright: © 2015 Ravndal E, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abstract
Background: Injecting drug users have a mortality risk between 10 and 20 times higher than the general
population, and the persistent high mortality rate in most Western countries, and especially in Norway, is a major
public health concern. Naturalistic, prospective studies following drug abusers over many years are needed in order
to investigate the most important predictors of mortality and for planning strategic preventive measures.
Methods: Four hundred and eighty-one drug abusers were followed prospectively for 10 years after admission to
treatment during the period 1998-2009. Following instruments were used: the European Addiction Severity Index,
Symptom Checklist-25 and Millon Clinical Multiaxial Inventory-II. Information on deaths and causes of death were
obtained from the National Death Register. Cox regression analysis was used to analyze factors hypothesized to be
associated with the risk of death.
Results: A total of 74 deaths were registered during the observation period, which represents a mortality rate of
1.5 per 100 person-years. The main cause of death was overdose, and the relative risk of mortality among males
was twice that of females.
Conclusions: Fifteen percent of the drug users in the study died during the 10 years after admission to index
treatment. This represents an annual mortality rate of 1.5; which is in line with most similar studies from Europe,
showing a mortality rates in the range of 1-2% per year. The main cause of death was overdose (68%). Preventive
strategies aiming to reduce mortality among drug users have to be manifold and gender specific, taking into account
drug abusers’ life conditions, their modes of thought and how they go about living their lives.
Keywords: Drug abuse; Mortality; Overdoses; Treatment;
Prospective
Introduction
There is a high mortality rate among drug abusers, and death by
overdose is the most common cause of death [1-4]. In general, just
being a drug abuser, and especially being a heroin injector, increases
the risk of early death. Users who inject drugs have a mortality risk
between 10 and 20 times higher than the general population [5]. The
persistent high annual mortality rate among drug abusers in most
Western countries is a major public health concern.
Men who have injected drugs over many years are at particularly
increased risk of dying from overdoses of injected heroin, most often
in combination with other substances such as benzodiazepines and
alcohol [4,6,7]. Those who die of an overdose have often had previous
nonfatal overdoses [2,8,9], and the majority of these deaths occur at a
residential address [4,10,11]. Also, releases from prison, or in- and
outpatient treatment, are particularly critical periods [3,10,12-15],
mainly because of injecting heroin when tolerance from opiate use is
reduced. Altogether, death by overdose is caused by a complex
interplay between several factors, and an essential task is to try to
target these factors with preventive measures [4,10,16,17].
Compared to international statistics, Norway ranks low in the
number of people who have tried illegal drugs, but high (relatively) in
per capita drug related deaths [5]. The peak year was in 2001 with 405
registered deaths (The WHO ICD coding system versions 9 (code 304)
and 10 (a combination of F, X and T codes were used in accordance
with the EMCDDA standard protocol for unintentional death) defined
these figures), followed by a drop in 2003 (255 deaths) and a more or
less stable situation up till 2013 [18]. Opiate maintenance treatment
(OMT), which was introduced nationally in Norway in 1998, and
other measures to establish low thresholds facilities, seem to have
reduced mortality, but still remains a matter of national concern [2].
Prospective studies conducted over longer time periods to
investigate factors associated with mortality are rare. Such studies are
difficult to implement and costly in terms of finances and other
resources required. This paper presents a naturalistic, prospective
study of 481 drug abusers, entering 20 different in- and outpatient
treatment facilities in Norway, and followed for 10 years. Given the
high death rate among drug abusers in Norway we expected that the
death rate would be higher in this treatment cohort than in similar
Addiction Research & Therapy
Ravndal, et al., J Addict Res Ther 2015, 6:1
http://dx.doi.org/10.4172/2155-6105.1000216
Research Article Open Access
J Addict Res Ther
ISSN:2155-6105 JART, an open access journal
Volume 6 • Issue 1 • 216
populations internationally. On the other hand research also shows
that being in treatment protects from drug related deaths [1,3].
However, during a 10-year observation period, one would expect that
a considerable percentage of the sample would drop out from
treatment and start new treatment episodes in other programs, thus
increasing the numbers of dropouts and at the same time increasing
the risk for overdoses [3,13]. During a 10-year period, some would also
finish serving their sentences, leave prison and be in great danger of
overdose death [14,19,20].
Although several studies have been conducted to identify factors
associated with drug related deaths [1,4,15], Degenhardt et al. [1]
suggest that mortality among opioid dependent users may vary across
countries, populations and time periods. To improve prevention of
drug related mortality, more knowledge of different drug abuse
populations in different countries and cultures is necessary, following
cohorts of drug abusers over years and in new time periods.
The aim of this study was to investigate the following questions: 1)
What was the mortality rate in a cohort of treatment-seeking drug
abusers during a 10-year period (1998-2009) including the time spent
in index treatment? 2) What were the main causes of death? 3) To
what extent were patient characteristics and time in index treatment
associated with increased risk of death by overdose and of death by
other causes?
Methods
Design and study setting
The study is a prospective, naturalistic study of 481 substance
abusers who consecutively entered 13 inpatient (n=307) and 7
outpatient (n=174) programs in Oslo and surrounding counties
between January 1998 and August 2000. The programs were purposely
chosen to provide a sample of the most widely used treatment
programs in Norway at the time. Additionally, the programs were
chosen for practical reasons, thus excluding similar treatment
programs situated in regions far away from Oslo. The majority of these
programs worked for the intention for patients to stay for extended
periods of time. In 1998 the first national treatment program for
Opiate Maintenance Treatment (OMT) started and also this program
was included in the study.
Participants, recruitment and procedures
Participation in the study was voluntary. Few of the residential
patients refrained from participating (n=12). It was more difficult to
engage all potentially eligible outpatients in the study, mostly due to
drop out from treatment after the first sessions. However, these
patients did not differ significantly from the rest in terms of
background characteristics (21). Participants were recruited from two
types of inpatients and two types of outpatient programs, including
both adults and younger patients.
All patients were assessed during the first two weeks of the index
treatment. They were interviewed and rated, using the European
Addiction Severity Index (EuropASI) [22]. Participants also completed
two self-report questionnaires: the Symptom Checklist 25 (HSCL-25)
[23] and the Millon Clinical Multiaxial Inventory II (MCMI II) [24].
The EuropASI is a personal, structured interview that covers seven
areas: medical status, employment and support status, drug and
alcohol use, legal status, family history, family and social relationships
and psychiatric status [22,25]. Further questions were added that were
specific to the Norwegian social security system, with detailed
questions about earlier in- and outpatient treatment, questions about
children and child-care arrangements, learning and/or behavioural
problems in primary school and contact with the child welfare
services. At baseline staff in eleven treatment programmes interviewed
all new patients, while the researchers (ER and GL) interviewed the
rest of the sample (n=231). All follow-up interviews were performed
by ER and GL and by specially trained interviewers (social workers
and master students). All interviewers were trained at an authorised
EuropASI course.
The HSCL-25 is a 25-item self-report inventory, assessing
symptoms of depression and anxiety [23]. The mean overall score, the
General Symptom Index (GSI) measures total symptom score in the
week prior to the interview. Clients with mean score of 1.0 and above
are considered “cases”. In the analyses the depression and anxiety
scores were used as well as the GSI index.
The MCMI II is a self-report instrument with 175 true/false items
measuring 13 personality profiles and nine clinical syndromes
according to the DSM-III-R system [24]. Scores on MCMI are
reported as Base Rate (BR) scores that are transformed raw scores
adjusted for gender differences. According to international practise,
patients who score 85 and above are considered to have a Personality
Disorder (PD).
National death register
Information on deaths and causes of death (ICD coded) was
obtained from the National Death Register kept by Statistics Norway
(SSB, 2013). Inclusion of deaths in the “overdose” category is based on
ICD codes F11 and X42 with opioid use as the main cause of death.
Statistical analyses
Mortality rate was calculated by the number of deaths divided by
the number of 100 person years at risk. Categorical variables were
analysed using chi-square and t-tests were employed for continuous
variables. Highly skewed continuous data were analysed using the
Mann-Whitney U statistic, a non-parametric analogue of the t-test.
Because of quite skewed variables bivariate relationships were
examined with Spearman’s rho. First differences in background
variables before index treatment were tested between the deceased and
non-deceased group of clients. Then Cox regression analysis was used
to analyse factors hypothesized to be associated with the risk of death.
Statistics were performed by SPSS version 19.0.
Ethics
This study was approved by the Norwegian Medical Ethics
committee and the Norwegian Data Inspectorate.
Results
Deceased patients
A total of 74 deaths (15%) were registered among the 481 study
participants during the ten-year observation period. Ten of these were
females and 64 were men. This represents a mortality rate of 1.5 per
100 person-years, 2.0 for males and 0.6 for females.
Citation:
Ravndal E, Lauritzen G, Gossop M (2015) A 10-year Prospective Study of Mortality among Norwegian Drug Abusers after Seeking
Treatment. J Addict Res Ther 6: 1000216. doi:10.4172/2155-6105.1000216
Page 2 of 6
J Addict Res Ther
ISSN:2155-6105 JART, an open access journal
Volume 6 • Issue 1 • 216
The mean (and median) age at baseline for deceased patients was 32
years (range: 14-52, SD=8.1), 32 years for males and 29 years for
females (ns) (Table 1). Mean age at death was 36 years (range: 18-55,
SD=8.6; 37 years for males, 33 years for females, ns). Death occurred
on average 51.4 months (range: 3-122, SD=33.5) after entering index
treatment; 52.3 months (range: 3-122, SD=33.5) for males and 44.5
months (range: 5-93, SD=34.4) for females (ns).
Men 68%
Women 32%
Ethnic Norwegian 94%
Age, mean
31 years (SD=8.1; range: 14-54
yrs)
Never married 79%
One or more children 44%
Daily care of children 8%
Stable accommodation 48%
Unstable accommodation, last 6 months
(prison, in-patient treatment, family,
friends)
52%
Only completed primary school 71%
Income/support last 30 days
Full/part time work 17%
Social security 58%
Disability pension/rehabilitation 24%
Drug sales/criminality 67%
Table 1: Sociodemographic characteristics for the total sample at
intake to index treatment (n=481)
Main causes of death
Overdose-related mortality was the most common specific cause of
death for 68% of the sample. Fifteen percent died what was recorded as
a “violent death” (traffic accidents, drowning, suicide, homicide, etc.),
two persons died from AIDS/HIV and one from hepatitis C. Six cases
were registered with uncertain/unknown cause of death, but all of
them had toxicological findings from poly drug use. Nine out of ten
women died from overdose. Forty-one out of 64 men (64%) died from
a drug overdose.
Sample characteristics at intake to index treatment
Sociodemographic characteristics are shown in Table 1. Sixty-eight
percent of the sample was male and the mean age at treatment intake
was 31 years (SD=8.1; range: 14-54 yrs). During life time 73% had used
heroin for one year or more, 75% had used amphetamines and 83%
had been injecting for a year or more. During the last 30 days before
intake to treatment, 62% had used heroin, 34% amphetamines (69%
had injected), 51% benzodiazepines, and 18% reported alcohol abuse
(According to EuropASI alcohol abuse is defined as use of alcohol at
least 3 days per week, with five or more alcoholic units a day, or two-
days binge drinking, making daily functioning difficult). At baseline
59% reported one or more nonfatal overdoses throughout life, the
mean number were four (median=1) (SD = 9.3, range: 0-9). Forty-two
percent reported one or more suicide attempts in total life (mean: 1.3,
SD=2.9, range: 0-3.5). The correlation between number of nonfatal
overdoses and number of years injecting was 0.44, while the
correlation between nonfatal overdoses and suicide attempts was 0.28.
Fifty percent were cases on GSI as measured by SCL-25, and 75%
had one or more personality disorders according to MCMI-II. Sixty-
one percent reported having previously been in inpatient treatment
one or more times in their lives, and the mean number of months in
prison was 13 (SD=23.0, range: 0-99) (When the number reported was
higher than 100 we consequently used 99 as a symbol (12 persons
reported having been in prison more than 100 months)).
Men were on average three years older than the women (32 vs. 29
yrs, p<0.001), they had spent more time in prison (17 months vs. 5
months, p<0.001), and they had higher scores on MCMI antisocial PD
than the females (89 vs. 84; p<0.05). The males also had higher scores
on MCMI alcohol dependence (76 vs. 68, p<0.001) and MCMI drug
dependence (88 vs. 84, p<0.05) than the females. Females had used
more benzodiazepines than the males the last month before the
baseline interview (11 vs 9 days) (p<0.05), and they had higher scores
on MCMI histrionic PD than the males (80 vs. 67, p<0.001). There
were no gender differences in the depression or anxiety scores as
measured by HSCL-25.
Differences between deceased and non-deceased patients at
intake to treatment
Table 2 indicates that the patients who died in the course of the
study (deceased patients) were somewhat older than the ones who
survived (non-deceased) at intake to treatment (32 vs. 30 yrs), they
had more years with alcohol abuse before index treatment (7.8 vs. 5.3,
p<0.05), they had had more nonfatal overdoses (5.9 vs. 3.6, p<0.05),
and they had spent more time in prison than the non-deceased clients
(19 vs. 12 months, p<0.05) (table 2). There was also a tendency for the
deceased patients to have higher scores on MCMI antisocial PD than
the non-deceased patients (91 vs. 86, p=0.07). There were no
differences in injecting drug use between deceased and non-deceased
patients.
Deceased
(n=74)
Non
deceased
(n=407)
t-test p-value
Mean (SD) Mean (SD)
Age (yrs) 32 (8.13) 30 (8.02) -1.51 ns
Alcohol abuse, lifetime (yrs) 7.8 (7.79) 5.3 (5.29) -2.18 <0.05
Number of non-fatal
overdoses, lifetime
5.9 (11.12) 3.6 (8.88) -1.99 <0.05
Injecting drugs, lifetime
(yrs)
11.3 (8.09) 9.5 (8.54) -1.66 ns
Months in prison, lifetime 19.2 (24.83) 11.8 (22.52) -2.53 <0.05
Table 2: Differences in background characteristics before index
treatment between deceased and non-deceased clients.
Except for the patients in opiate maintenance treatment (OMT)
(n=74) 41% of the total sample completed their index treatment
programme. The retention rate in OMT after ten years was 58%. There
Citation:
Ravndal E, Lauritzen G, Gossop M (2015) A 10-year Prospective Study of Mortality among Norwegian Drug Abusers after Seeking
Treatment. J Addict Res Ther 6: 1000216. doi:10.4172/2155-6105.1000216
Page 3 of 6
J Addict Res Ther
ISSN:2155-6105 JART, an open access journal
Volume 6 • Issue 1 • 216
were no significant gender differences in dropout rates from any
treatment modality. Deceased patients were more likely to have
dropped out of index treatment than non- deceased patients (64% vs.
55%, chi-square 31.43, p<0.001).
Patient characteristics and treatment variables as predictors
of mortality
According to table 3, the strongest predictor of mortality was
gender; males had 2.8 times greater chances than females of dying
prematurely (p<0.01) (Table 2). Also spending a total of more than
one year in prison before intake to index treatment increased the
chances of early death compared to those who had been incarcerated
less (p<0.05). Likewise, having several nonfatal overdoses before index
treatment portended mortality more frequently as compared to those
with no or fewer nonfatal overdoses (p<0.05). In addition, patients
who dropped out of index treatment had more chances of dying
during the observation period than patients who completed (p<0.05)
the period. In a further regression model, where the variable time in
treatment was included in the analysis instead of dropout, the
treatment variable was not significant. The correlation between
dropout and time in index treatment was 0.48 (Pearson’s r).
Beta SE p-value Exp (B) CI (95%)
Gender 1.02 0.35 <0.01 2.77 1.39-5.51
Age -0.01 0.17 ns 0.99 0.96-1.03
Non-fatal overdoses
(yes-no)
0.58 0.28 <0.05 1.79 1.04-3.07
No use of syringes
(last 30 days)
Use of syringes
(1-29 days)
0.05 0.33 ns 1.05 0.55-2.00
Use of syringes
(all last 30 days)
- 0.07 0.32 ns 0.94 0.50-1.76
Prison > 12 months
(yes-no)
0.59 0.26 <0.05 1.80 1.09-2.97
Alcohol abuse
>5 yrs (yes-no)
0.42 0.25 =0.09 1.52 0.93-2.48
Dropout
(yes-no)
0.57 0.26 <0.05 1.77 1.06-2.98
Table 3: Client characteristics before admission to treatment and
dropout as predictors of mortality, Cox regression analyses (n=481).
Discussion
Fifteen percent of the drug users in the study died during the 10
years after admission to index treatment. This represents an annual
mortality rate of 1.5: 2.0 for males and 0.6 for females. The main cause
of death was overdose (68%). Being a male was by far the strongest
predictor of all causes of mortality, but previous nonfatal overdoses,
time in prison before baseline, as well dropout from index treatment
were also related to increased mortality. A mortality rate of 1.5 is in
line with most studies from Europe, which show mortality rates in the
range of 1-2% per year among problem drug users.
As in other studies, the mortality rate among men was higher than
among the women [1,2, 4,9,10,15,26]. The relative risk of mortality
among the male drug abusers was 12 times higher compared to the
age-adjusted general Norwegian male population [27]. The
corresponding number among the females was six times higher
compared to the age-adjusted general female population [27]. Males in
the general population also have about twice the age-adjusted
mortality risk as females [27]. This difference in mortality between
males and females underscores the importance of getting more gender
specific knowledge about mortality in order to implement preventive
measures especially tailored to address the specific needs of men and
women.
The main cause of death was overdoses (68%), which is consistent
with other studies [1,2,4,10,26]. The majority died from heroin
overdose but these deaths were also characterised by poly drug
intoxications. Somewhat surprisingly, all but one of the women died
from overdoses (90%) compared to 59% of the men. It seems that
contrasting findings in studies of female drug abusers may be due to
different designs, populations and data collected, even within the same
country [10,28,29]. The deceased females were on average four years
younger than the males at time of death, they used less heroin than the
males all through the observation period and fewer entered OMT.
However, like the males they had a typical poly drug use, but with
more use of benzodiazepines at index treatment. Autopsies of drug
related deaths indicate that in many cases levels of heroin/morphine
was low, but that poly drug use was common [30]. The lack of
association between fatal overdose and injecting drug use may be a
consequence of the high percentage of injection users in the sample
(83%).
Fifteen percent, and only males, died from what was classified as a
violent death (traffic accidents, drowning, suicide, homicide etc.).
Similar findings have been reported in other studies [2,4,10,28]. In all
these cases the use of other substances was also found. Only two
persons died from AIDS, which is consistent with findings in countries
with a low prevalence of HIV/AIDS [5].
Time in prison prior to index treatment was a significant predictor
of death after discharge from treatment. One possible explanation of
this finding may be that this group of males was more antisocial and
prone to taking risks, and both of these factors could lead to more
crime and a more reckless lifestyle, including death by overdose. Even
if MCMI antisocial PD was not a significant predictor of death in the
regression analysis, there was a tendency for the deceased patients to
have had higher scores on MCMI antisocial than the non-deceased
clients. This finding is in line with another Norwegian study of drug
users in which male gender, antisocial PD, and time in prison were
related to death five years later [26]. Important preventive strategies
for males should therefore be tailored especially to antisocial males
with a criminal record, as opposed to females who seem to have
another personality style and more use of benzodiazepines. However,
we need more knowledge about overdoses among females to indicate
gender specific preventive strategies.
Having had one or more nonfatal overdoses before index treatment
was also associated with death. This corresponds with the findings
from the three-year follow-up Australian Treatment Outcome Study
(ATOS), where previous nonfatal overdose experience was related to
subsequent nonfatal overdoses [31]. Having a history of nonfatal
overdoses may also be associated with living a more reckless life.
Citation:
Ravndal E, Lauritzen G, Gossop M (2015) A 10-year Prospective Study of Mortality among Norwegian Drug Abusers after Seeking
Treatment. J Addict Res Ther 6: 1000216. doi:10.4172/2155-6105.1000216
Page 4 of 6
J Addict Res Ther
ISSN:2155-6105 JART, an open access journal
Volume 6 • Issue 1 • 216
In the present study the association between number of life-
threatening overdoses and number of suicide attempts was not high,
and in line with another prospective Norwegian treatment study of
drug abusers, demonstrating that overdoses and suicide attempts may
be distinguished on the basis of their disparate psychopathological risk
variables and their different relationships to substances [17]. Screening
for both previous overdose experience and suicide attempts is advised
to identify drug users who are at risk of overdoses and/or suicide
attempts.
Patients who completed treatment had a lower risk of dying during
the 10 year follow-up. Patients who stay in treatment for prolonged
time have better outcomes than patients who drop out or spend less
time in treatment [26,32-35]. The first weeks after leaving inpatient
treatment, when drug tolerance is low, comprise a critical period.
Preventive strategies should therefore be specially tailored towards
patients who leave treatment prematurely as well as towards patients at
treatment completion.
The deceased patients reported more alcohol abuse prior to index
treatment, and abuse of alcohol for more than five years before
baseline was close to being a significant predictor of death (p=0.09).
This tendency is consistent with other studies showing an association
between abuse of alcohol and overdoses [4,15,36]. However, only 18%
in our total sample reported alcohol abuse before index treatment. In a
recent Norwegian study of drug-induced deaths, alcohol was found in
only 15% of the cases, whereas the most common combination of
drugs was heroin and benzodiazepines (50%) [10]. Whereas most
Norwegian heroin injectors also use benzodiazepines, less than half
reported combined use with alcohol [29]. Our findings probably
mirror the Norwegian pattern of drug use, with a high prevalence of
heroin injection and poly drug use, often including a frequent use of
benzodiazepines, but less use of alcohol.
As for preventive measures, there are no easy solutions at hand. The
behavior of heroin users is often difficult to change. Those who may be
in most need of organized treatment for their drug dependence as well
as their other mental health disorders, may also be the ones who live
under the most marginalized conditions and despair, and thus may
both be difficult to reach and to keep in a rehabilitation process. A
qualitative study of experiences with overdoses among Swedish heroin
users is instructive in this context. The participants were aware of
many of the common risk factors for overdoses. In spite of this, most
overdoses occurred as a result of conscious risk-taking behavior.
Search for the ‘ultimate rush’, as well as severe abstinence, anxiety and
depression, feelings of indifference and dependency, and an unsafe,
stressful environment were examples of factors that undermined the
consideration of risks [16]. The authors conclude that heroin
overdoses cannot be fully understood simply by defining a variety of
isolated factors. It is more important to bolster understanding of how
heroin users perceive and evaluate the risk they are taking, and what
circumstances and which emotions and motives influence risk-taking
that may lead to overdose.
Treatment providers and healthcare authorities are advised to
further strengthen preventive strategies. Patients in treatment should
take part as early as possible in overdose prevention awareness
programs with particular emphasis on the nature of overdose risk in
the event of their leaving treatment prematurely. Drug users also
represent an overlooked potential workforce; they can be interested in
and willing to attend preventive training courses and to apply such
knowledge when necessary [37-39]. Programs to prevent fatal
overdoses may be established and evaluated in the community, using
resuscitation techniques as well as opioid antagonist medication such
as naloxone [37,40-42]. Preliminary results indicate lifesaving events
through peer administration of naloxone [37,43]. This research is still
a young but promising field.
Better cooperation and communication between the health and
social services are needed to identify and address the individuals, who
are at particular risk, especially those characterized with multiple risk
factors [10]. Preventive strategies must be planned and carried out in
treatment and community settings alike, and in continuous
cooperation between active users of heroin, clients in treatment, the
families of heroin users, and healthcare and social service authorities.
Outreach strategies should also be implemented to minimize
destructive life-style patterns by crisis interventions and the use of
low-threshold measures [44]. A wide range of preventive strategies is
required if overdose deaths are to be reduced. Only a broad
cooperation between all involved parties can help ensure that fewer
heroin users, old and young alike, die from accidental or planned
overdoses.
Limitations and strengths
Factors leading to overdoses and death are complex. In this study
we have analyzed patient characteristics and treatment dropout as
predictors, knowing that other factors may be associated with
premature deaths. Also, all reports were self-reports and some bias in
data is possible. The strength of the study lies in the prospective design
and the length of the study period. Few studies of mortality among
drug abusers have been able to follow a cohort of patients over a
period of ten years.
Conclusions
The annual mortality rate in this study was 1.5, which is in line with
similar studies from Europe. The mortality rate was by far the highest
among the men, and the main cause of death was overdoses. The
deceased females were on average four years younger than the males at
time of death, they used less heroin than the males all through the
observation period, fewer entered OMT, and all died from overdoses.
Male gender, lengthy time in prison prior to index treatment, having
had several overdoses prior to index treatment and dropout from
index treatment were all independent and significant predictors of
premature death. Outreach strategies should be implemented to
minimize destructive life-style patterns by crisis interventions and the
use of low-threshold measures. A wide range of preventive strategies is
required if overdose deaths are to be reduced.
References
1.
Degenhardt L, Bucello C, Mathers B, Briegleb C, Ali H, et al. (2011)
Mortality among regular or dependent users of heroin and other opioids:
a systematic review and meta-analysis of cohort studies. Addiction 106:
32-51.
2.
Clausen T, Anchersen K, Waal H (2008) Mortality prior to, during and
after opioid maintenance treatment (OMT): a national prospective cross-
registry study. Drug Alcohol Depend 94: 151-157.
3.
Davoli M, Bargagli AM, Perucci CA, Schifano P, Belleudi V, et al. (2007)
Risk of fatal overdose during and after specialist drug treatment: the
VEdeTTE study, a national multi-site prospective cohort study.
Addiction 102: 1954-1959.
4.
Gossop M, Stewart D, Treacy S, Marsden J (2002) A prospective study of
mortality among drug misusers during a 4-year period after seeking
treatment. Addiction 97: 39-47.
Citation:
Ravndal E, Lauritzen G, Gossop M (2015) A 10-year Prospective Study of Mortality among Norwegian Drug Abusers after Seeking
Treatment. J Addict Res Ther 6: 1000216. doi:10.4172/2155-6105.1000216
Page 5 of 6
J Addict Res Ther
ISSN:2155-6105 JART, an open access journal
Volume 6 • Issue 1 • 216
