ABSTRACT
Objectives To examine survival and long term cessation of
injecting in a cohort of drug users and to assess the
influence of opiate substitution treatment on these
outcomes.
Design Prospective open cohort study.
Setting A single primary care facility in Edinburgh.
Participants 794 patients with a history of injecting drug
use presenting between 1980 and 2007; 655 (82%) were
followed up by interview or linkage to primary care records
and mortality register, or both, and contributed 10 390
person years at risk; 557 (85%) had received opiate
substitution treatment.
Main outcome measures Duration of injecting: years from
first injection to long term cessation, defined as last
injection before period of five years of non-injecting;
mortality before cessation; overall survival.
Results In the entire cohort 277 participants achieved
long term cessation of injecting, and 228 died. Half of the
survivors had poor health related quality of life. Median
duration from first injection to death was 24 years for
participants with HIV and 41 years for those without HIV.
For each additional year of opiate substitution treatment
the hazard of death before long term cessation fell 13%
(95% confidence interval 17% to 9%) after adjustment for
HIV, sex, calendar period, age at first injection, and
history of prison and overdose. Conversely exposure to
opiate substitution treatment was inversely related to the
chances of achieving long term cessation.
Conclusions Opiate substitution treatment in injecting
drug users in primary care reduces this risk of mortality,
with survival benefits increasing with cumulative
exposure to treatment. Treatment does not reduce the
overall duration of injecting.
INTRODUCTION
Injection drug use is an important public health problem
with a prevalence of around 1-2% among young
adults in the United Kingdom and a standardised mortality
ratio over 10 times that of the general
population.1 Deaths in those who inject opiates are
mainly a consequence of overdose and bloodborne
infection.2 The principal treatment for dependent
users is opiate substitution therapy, commonly oral
methadone,3 which in the UK is mostly delivered in
primary care settings. Opiate substitution treatment
can reduce opiate use, mortality, and transmission of
bloodborne infections, though most evidence comes
from relatively short term studies.4-8
Short periods of cessation from injecting are relatively
common,9 but few studies have long enough follow-
up to observe long term cessation, and the impact
of opiate substitution treatment on the overall duration
of injecting is unclear.10
We report on a follow-up study of the Edinburgh
addiction cohort.11 This study included injecting drug
users, most of whom were using heroin, recruited
through Muirhouse Medical Group, a single primary
care facility in a deprived area of Edinburgh, during a
rapid local HIV epidemic.12 We describe the duration
of injecting and survival and assess the influence of
opiate substitution treatment and other factors on
these outcomes.
METHODS
Data source
Methods are described in detail elsewhere.11 13 Briefly,
between 1980 and 2006 all patients at a large primary
care facility in Edinburgh who reported a history of
injecting drug use were recruited to the study. Opiate
substitution treatment was publicly funded and accessible
to patients throughout the study period, in keeping
with national guidelines. Cohort members were
flagged with the General Register Office for Scotland
to allow for tracing of deaths and changes of general
practitioner. From October 2005 to November 2007
we attempted to contact all surviving cohort members
to conduct a follow-up interview. Information was also
collected from primary care notes when these were
available.

Read the whole study, it is the longest ever:Methadon, scotland