Measuring opioid dependence in chronic pain patients: A comparison between addiction clinic and pain clinic patient populations.

Abstract

To compare dependence characteristics between patients with chronic pain treated within an addiction medicine setting with those attending specialist pain clinics. Forty patients with chronic non-cancer pain taking opioid analgesics for >1 year were recruited from university-affiliated, tertiary teaching hospital clinics; 20 from an addiction medicine clinic (addiction clinic group) and 20 from specialist pain clinics (pain clinic group). Data regarding demographics, past and current substance use, pain history and current daily opioid intake were collected. Patients completed three questionnaires: the Severity of Opioid Dependence Questionnaire, Leeds Dependence Questionnaire, and Pain Disability Index. A novel "Opioid Problem Checklist score" assessing drug-related problems was also determined for each patient. The addiction clinic group were younger, more likely to have experienced drug overdose and had a shorter duration of chronic pain. No significant differences in dependence questionnaire scores were found between groups. However, higher Pain Disability Index scores and higher Opioid Problem Checklist scores (indicating more drug-related problems) were found for the addiction clinic group. Some degree of dependence was present across both addiction and pain clinic groups, supporting the notion a state of dependence can be identified among chronic pain patients taking opioids long term. Aberrant behaviors were not common in the pain clinic sample, suggesting these patients are unlikely to meet Diagnostic and Statistical Manual of Mental Disorders-V criteria for Substance Use Disorder. However, opioid dependence carries significant risks for relapse, chronicity, morbidity and mortality, warranting specific medical management. Management of such risks should be considered routine care in chronic pain patients taking opioids long term.