Estimates of the Prevalence of Opiate Use and/or Crack Cocaine Use, 2011/12
Please note the following caveats concerning the 2011/12 estimates:
1) Regional estimates featured in these documents use the nine regions in operation in 2011/12. This is to ensure consistency with previous sweeps of these estimates and other data (including treatment data) already published for the same period.
2) 2011/12 prevalence rates calculated in these documents use 2011 mid-year population estimates produced by the Office for National Statistics (ONS). These population estimates were the first new estimates to be published by ONS following the 2011 census, which led to revisions from previous mid-year population estimates. The published 2010/11 prevalence rates used the 2010 ONS mid-year population estimates available at the time of publication. This will affect the comparability of prevalence rates between the two years for some local areas.