Provider referral, self-referral, and contract referral are three strategies used to inform past partners of possible sti infection.

"Provider referral, self-referral, and contract referral are three strategies used to inform past partners of possible STI infection."---This statement is a FACT.
 There are three main approaches to partner notification, for notifying sexual partners of those with confirmed STI.
1. Patient-based referral’, or patient referral (often self-referral )
2. Provider referral which involves a third party in notification.
3. contract referral which is also known as conditional referral

Ibelieve this would be an obstacle.