Predictors of long-term opioid effectiveness in chronic non-cancer pain patients attending multidisciplinary pain treatment clinics : a Quebec pain registry study

Objective: This study aimed at identifying characteristics of individuals who are most likely to benefit from long-term opioid therapy in terms of reduction in pain severity and improved mental health-related quality of life (mQoL) without considering potential risks. Methods: This was a retrospective cohort study of 116 patients (age=51.3 ±12.5 years, male=42.2%) enrolled in the Quebec Pain Registry between 2008 and 2011 and who initiated opioid therapy after their first appointment in a multidisciplinary pain clinic and persisted with this treatment for at least 12 months. Clinically significant improvement was defined as a 2-point decrease on the PEG 0-10 Scale of pain severity at 12-month follow-up and a 10-point increase on the SF-12v2 Mental Health-Related Quality of Life Summary Scale which corresponds to one standard deviation of the mean in the general population (Mean = 50, SD = 10). Results: Clinically significant reduction in pain severity was observed in 26.7% of patients while improvement in mQoL was reported by 20.2% of patients on long-term opioid therapy. Older age (OR=1.04 (95% CI: 1.0 – 1.08), p=0.032) and alcohol or drug problems (OR=0.26 (95% CI: 0.07 – 0.96), p=0.044) were weakly associated with pain severity at 12-month follow-up. Baseline higher pain severity (OR=0.62 (95% CI: 0.43 – 0.91), p=0.014) and baseline higher mQoL (OR=0.89 (95% CI: 0.83 – 0.95), p=0.001) were associated with non-improvement in mQoL. Conclusion: The analysis failed to identify clinically meaningful predictors of opioid therapy effectiveness making it difficult to inform clinicians about which CNCP patients are most likely to benefit from long-term opioid therapy

Chronic Pain Experience and Management among People Who Use Illicit Drugs: A Qualitative Study in Montreal (QC)

Introduction/Aim: Chronic non-cancer pain (CNCP) is both highly prevalent and undertreated among people who use illicit drugs (PWUD). To address the current opioid crisis, several health authorities have produced guidelines recommending not to prescribe opioid painkillers to patients with substance abuse risk factors. This could jeopardize pain relief for PWUD suffering from CNCP. This study aims to describe: (1) PWUD’s daily CNCP experiences; (2) barriers of access to adequate CNCP management for PWUD in the opioid crisis context; (3) PWUD’s stated needs for improving their CNCP and healthcare experiences. Methods: This was a qualitative study. In-depth semi-structured interviews were conducted with 25 PWUD (illicit opioids and/or cocaine) suffering from CNCP (≥ 3 months) recruited in downtown Montreal (2017/07 to 2018/05). Interviews were analyzed using Grounded Theory method. Results: Participants faced multiple health problems (e.g. HIV, hepatitis C) and social issues (e.g. homelessness, precarious employment) concomitantly with CNCP and substance use. These problems contributed to heighten their pain intensity. Physicians’ increased defiance against PWUD in the opioid crisis context led to major barriers for participants’ pain management. Participants experienced stigma and discrimination in the healthcare system. They wished they could access non-pharmacological therapies (e.g. physiotherapy) as alternatives to opioids, but these therapies were unaffordable. Some participants reported self-medicating their CNCP with street drugs when no other solution was available. Discussion/Conclusions: PWUD suffering from CNCP are a population with several comorbidities and high health care needs. Public policies should be revisited to improve access to appropriate CNCP management for this population