New opiate and crack-cocaine users: characteristics and trends 20 
 
Table 9: Table showing the age breakdown of individuals testing positive for opiates-only or 
positive-for-both as a proportion of all individuals first testing positive in that year. 
Year of 
first test 
Age  
18 - 24 
Age  
25 - 29 
Age  
30 - 34 
Age  
35 - 39 
Age  
40 over 
 
Total 
2004 26% 27% 24% 16% 7% 100% 
2005 23% 27% 24% 17% 9% 100% 
2006 25% 26% 22% 17% 11% 100% 
2007 24% 25% 21% 16% 13% 100% 
2008 21% 23% 21% 18% 16% 100% 
2009 23% 22% 20% 17% 18% 100% 
2010 22% 21% 20% 17% 20% 100% 
2011 22% 19% 20% 16% 22% 100% 
2012 19% 20% 22% 17% 23% 100% 
2013 17% 20% 22% 16% 25% 100% 
 
Comparing 2004 with 2013 shows that the younger age groups have seen falls in both the 
number and the proportion of new positive testers. However, the proportion of those aged 40+ 
has consistently risen and now constitutes the largest group of all new individuals testing 
positive. 
This means that the 4,281 individuals testing positive for the first time in 2013 has a very 
different age profile to that we would expect from a cohort of recent initiates. It is far older, 
suggesting again that many of those are actually pre-existing users only tested (positively) for 
the first time in 2013. This adds further weight to the back-of-the-envelope modelling evidence 
demonstrating that a substantial proportion of the 4,281 new positive testers in 2013 are likely to 
be longer-term users who have only been first arrested in 2013, rather than genuinely new 
OCUs. 
In the next section, analysis will examine whether there has been a possible shift towards an 
older profile amongst new initiates. But even taking this into account, it is unlikely that the 
majority of those 4,281 individuals are recent initiates. This can be seen clearly in Figure 8 
below, which compares the age-of-initiation curve from Figure 11 (in the next section) to the 
2013 ‘new-individuals’ cohort in the DIP data.