The purpose of the Swedish Prison Program which started back in 1987 and up until 2009 was called "The Social Medicine Remand Prison Project" is to target injecting drug users (IDU) with primary and secondary health interventions with regards to injecting and sexual risk behaviours and infectious diseases such as hepatitis C and B, HIV and sexually transmitted infections (STI).

The overall aim is to assess the effect of different prevention efforts on HIV/HCV risk behaviour and disease outcome among IDUs over time.

Risk behaviour for IDU is sexual risk taking, i.e., sex without a condom, buying or selling sex and injection risk taking, i.e., sharing needle, syringe or paraphernalia.

Inclusion Criteria:

• Defined as an injecting drug user, in the prison and probation service and agree to anonymously participate

Exclusion Criteria:

• Being defined as a non-drug user, non-injecting drug user