Risks for opioid abuse and dependence among recipients of chronic opioid therapy: Results from the TROUP Study

Objective: To estimate the prevalence of and risk factors for opioid abuse/dependence in long-term users of opioids for chronic pain, including risk factors for opioid abuse/dependence that can potentially be modified to decrease the likelihood of opioid abuse/dependence, and non-modifiable risk factors for opioid abuse/dependence that may be useful for risk stratification when considering prescribing opioids. Methods: We used claims data from two disparate populations, one national, commercially insured population (HealthCore) and one state-based, publicly insured (Arkansas Medicaid). Among users of chronic opioid therapy, we regressed claims-based diagnoses of opioid abuse/dependence on patient characteristics, including physical health, mental health and substance abuse diagnoses, sociodemographic factors, and pharmacological risk factors. Results: Among users of chronic opioid therapy, 3% of both the HealthCore and Arkansas Medicaid samples had a claims-based opioid abuse/dependence diagnosis. There was a strong inverse relationship between age and a diagnosis of opioid abuse/dependence. Mental health and substance use disorders were associated with an increased risk of opioid abuse/dependence. Effects of substance use disorders were especially strong, although mental health disorders were more common. Concerning opioid exposure; lower days supply, lower average doses, and use of Schedule III-IV opioids only, were all associated with lower likelihood of a diagnosis of opioid abuse/dependence. Conclusion: Opioid abuse and dependence are diagnosed in a small minority of patients receiving chronic opioid therapy, but this may under-estimate actual misuse. Characteristics of the patients and of the opioid therapy itself are associated with the risk of abuse and dependence. (C) 2010 Elsevier Ireland Ltd. All rights reserved.