text: Aspects of DIP have changed over time and this affects the data available, so it is important to 
  run through them briefly. In 2005, testing was switched from the point of charge to the point of 
  arrest. DIP was introduced in different areas in waves with the total number of areas increasing 
  through 2004 to 2006. After this point, there was more consistency in DIP’s geographical 
  coverage, though some other areas that were not part of the nationally funded programme, did 
  choose to run their own drug-testing-on-arrest programmes and some of these data have also 
  been collected within the DIP data. This process increased slightly from 2010 when all police 
  forces in England and Wales were given authorisation to conduct drug testing and related 
  treatment interventions. This enabled local partners in all areas to decide whether or not to 
  introduce drug testing as a locally driven approach to reducing drug-related offending. Again, 
  some of these data were also captured alongside the data from the original DIP areas. In April 
  2013, DIP ceased to be a nationally funded programme. Instead, Police and Crime 
  Commissioners (PCCs) were given the power to decide which local interventions (including drug 
  testing on arrest) they would fund to address Class A drug-related offending. Drug testing 
  continues to operate in many areas across England and Wales, but in some areas there may be 
  drop-off in the data from that point. 