Final answer:
Research has shown that PBS can reduce exposure to violence/trauma and improve physical health, but mental health and physical health of clients using PBS may still be worse than the general public's.
Step-by-step explanation:
The use of PBS (Positive Behavior Support) has been studied across all levels of prevention - Primary, Secondary, and Tertiary. Research has shown that PBS can have positive effects on reducing exposure to violence/trauma and improving physical health. However, it has also been found that mental health and physical health of clients using PBS still tend to be significantly worse than the general public's.