"Another control strategy that has gained traction is opioid 'contracts' or 'treatment agreements' between health care providers and patients, under which medication use by highrisk patients is closely monitored. In a study of a primary are clinic’s use of such contracts, three-fifths of patients adhered to the agreement (with a median follow-up of 23 months) (Hariharan et al., 2006). However, many pain experts have concluded that pain agreements/contracts do not necessarily improve the treatment of pain or minimize diversion and abuse of prescription drugs, particularly when used indiscriminately. A systematic review of the literature found only weak evidence to support either pain contracts or urine tests as a strategy for reducing opioid abuse (Starrels et al., 2010)."
Institute of Medicine, "Relieving Pain in America: A Blueprint for Transforming Prevention, Care, Education, and Research" (Washington, DC: National Academy of Sciences, 2011), p. 147.