The Effective Health Care (EHC) Program has issued two reports: 1) on integrated and comprehensive pain management programs; and 2) on management of high-need, high-cost patients.  To read the EHC report on integrated and comprehensive pain management programs, use the first link below.  To read the EHC report on management of high-need, high-cost patients, use the second link below.
https://effectivehealthcare.ahrq.gov/products/integrated-pain-management/research  (EHC report on integrated and comprehensive pain management programs)
https://effectivehealthcare.ahrq.gov/products/high-utilizers-health-care/research  (EHC report on management of high-need, high-cost patients)