New opiate and crack-cocaine users: characteristics and trends 4 
 
initiated use at an older age. Currently it is not possible to determine whether this is a 
reporting issue or a genuine shift in the age profile of new opiate/crack-cocaine users. 
 The report has several important policy implications. Even though numbers of new 
initiates involved with crime have dropped to the low thousands, putting downward 
pressure on crime, identification and early diversion to treatment remains paramount. 
Frontier Economics have estimated that the average4 lifetime crime cost of an injecting 
drug user is £445,000, so the potential for social harm – even from a small number of 
individuals – remains large and potentially long-lasting. This means local areas need to 
manage both the (relatively large) stock of current users, and the (much smaller) flow of 
new initiates, whose treatment needs may be different. There is no evidence of any new 
epidemic in this country, but given the impact of the epidemic of the 80s and early 90s on 
crime, ongoing monitoring of recent trends is required to spot early signs of any emerging 
problems.  
Aims and Methodology 
Previous Home Office research has demonstrated the importance of opiate/crack-cocaine use 
in driving aggregate trends in acquisitive crime (Morgan, 2014). While established estimates 
exist of the total number of opiate/crack-cocaine users (OCUs) in England (Hay et al., 2013), 
there are no estimates for the number of new OCUs each year (throughout this paper the 
number of new OCUs is also referred to as ‘incidence’). This is important for three main 
reasons. 
i) Stock and flows: Simply knowing the stock of OCUs tells us nothing about the flows in 
and out – i.e. if the stock were constant each year that could mean that no one starts 
using these drugs and no one quits or it could mean all existing users quit but that they 
are wholly replaced by new users, or any similar scenario in between. Clearly the policy 
response would need to be quite different for each of these cases, so knowing the true 
situation is important.  
ii) Early-warning system: Research by the Home Office and others has shown that there 
is generally a lag between the start of a heroin/crack epidemic and the point at which it 
becomes visible on administrative datasets. Closing this gap is important for policy, and 
part of the reason for its existence is the lack of incidence estimates. Evidence also 
suggests epidemics spread from area to area, so it is important to monitor local as well 
as national trends. 
iii) The social harm that can arise: Though research suggests that not all OCUs resort to 
acquisitive crime to help finance their drug use, numerous studies show that a 
proportion consistently do and these individuals can be extremely prolific offenders 
(Morgan, 2014). One study by Frontier Economics estimated that the average lifetime 
cost to society of an injecting drug user was £445,000 from crime alone. Hence 
analysing and identifying new OCUs is a policy priority (Frontier Economics, 2010). 
There are two inter-connected reasons why regular national incidence estimates have not been 
attempted before5. The first is that data on this issue are sparse given the ‘hidden’ nature of 
opiate/crack markets and that date of first use is not something that gets recorded at the 
moment it actually occurs. The second reason, which flows from the first, is that current 
 
4  The average is useful, but hides the fact that offending within the opiate/crack population is highly skewed with a few 
individuals responsible for the majority of crime and many individuals manage to use heroin and crack without resorting to 
acquisitive crime at all (Morgan, 2014). 
5  Though regular national-level estimates have not been attempted, studies have estimated incidence at various times and at