An Effectiveness, Safety and Quality of Life Measures With Hydromorphone HCL, Dilaudid CR (Controlled Release)

Inclusion Criteria: * Patient who met criteria (functional Class I-III in the hip or knee) for osteoarthritis for at least 3 months before enrollment * Patient who had moderate to severe chronic pain despite regular use and stable doses of an NSAID (nonsteroidal anti-inflammatory drug) or an NSAID with opioid analgesic taken as needed but not on a daily basis for the treatment of osteoarthritis. Exclusion Criteria: * Patient intolerant of or hypersensitive to hydromorphone or oxycodone * Patient of childbearing potential must use medically recognized contraceptive program before and during the study * Pregnant or breastfeeding * Patient who had prior joint replacement of the target knee or hip * Patient with significant respiratory compromise or depressed ventilatory function * Patient who was known active drug abuser or alcoholics.