There may be other reasons for those fewer refusals. I would image there may be other consequences, or carrots, or sticks.
Here's a comment by Dr. Julio Montaner, one of the world's leading researchers for HIV/AIDS treatment and now prevention. His model has been adopted by China as a whole. His comment is that the best way to prevent HIV/AIDS infections is to have fewer people in prison. We did hear that it's seven to ten times more likely for a person to be living with HIV/AIDS, with all of the attendant costs for our health system, if they've been in prison than the general population.