Pharmaceutical Opioid Use Patterns and Indicators of Extramedical Use and Harm in Adults With Chronic Noncancer Pain, 2012-2018.

Importance: Despite concern about harms related to long-term prescribed opioid use among individuals with chronic noncancer pain (CNCP), no study has examined whether the same patients engage in a risky pattern of use consistently for the long term. Objective: To examine the prevalence, incidence, persistence, and cessation of a range of opioid behaviors, indicators of extramedical use, and harm among individuals who are prescribed opioids. Design, Setting, and Participants: This 5-year prospective cohort study in communities across Australia included 1514 adults who were prescribed opioids for CNCP. Data collection took place from August 2012 to December 2018, and data analysis took place from February to November 2020. Exposure: Prescription opioid use. Main Outcomes and Measures: High-dose opioid use (≥200 oral morphine equivalent [OME] mg/d); requesting an increase in opioid dose; requesting an early prescription renewal; tampering with opioid medication; diversion of medication to others; and International Statistical Classification of Diseases and Related Health Problems, Tenth Revision opioid dependence. Cessation of opioid use was also assessed. Results: Of the 1514 participants, 672 (44.39%) were men, the mean (SD) age was 58 (19) years, and 737 (48.68%) were unemployed. At each annual interview, approximately 1 in 8 people (10.98% [95% CI, 10.33%-11.63%] to 14.73% [95% CI, 13.98%-15.48%] at any given interview) were taking more than 200 OME mg/d; comparatively more had requested an increased dosage in the previous 3 months (8.46% [95% CI, 7.89%-9.03%] to 23.77% [95% CI, 22.82%-24.73%]); and fewer asked for an early prescription renewal (4.61% [95% CI, 4.19%-5.03%] to 13.97% [95% CI, 13.24%-14.70%]). In any given interview, between 3.06% (95% CI, 2.72%-3.40%) and 7.86% (95% CI, 7.31%-8.41%) of respondents reported tampering and between 0.47% (95% CI, 0.33%-0.60%) and 1.39% (95% CI, 1.16%-1.62%) reported diversion to others. Between 8.28% (95% CI, 7.71%-8.84%) and 13.06% (95% CI, 12.35%-13.77%) met criteria for opioid dependence at each interview. Opioid cessation increased across interviews, from year 1 (9.15% [95% CI, 8.55%-9.74%]) to year 5 (20.02% [19.14%-20.89%]). There was considerable incidence and cessation in all behaviors from 1 interview to the next: most who engaged in any of these behaviors only did so at only 1 interview. For pharmaceutical opioid dependence, between 55.26% (95% CI, 53.81%-56.71%) and 64.44% (95% CI, 62.87%-66.00%) of cases in 1 interview did not meet dependence criteria in the following interview. Conclusions and Relevance: These findings suggest considerable fluidity in opioid use, extramedical behaviors, and opioid dependence among people with CNCP. This reinforces the need for reassessment of the effectiveness and safety of prescription opioid use over time.

Risk factors for indicators of opioid-related harms amongst people living with chronic non-cancer pain: Findings from a 5-year prospective cohort study.

BACKGROUND: The literature suggests patient characteristics and higher opioid doses and long-term duration are associated with problematic opioid behaviours but no one study has examined the role of all these factors simultaneously in a long-term prospective cohort study. METHODS: Five-year, community-based, prospective cohort of people prescribed opioids for chronic non-cancer pain (CNCP). Logistic mixed effect models with multiple imputation were used to address missing data. Oral morphine equivalent (OME) mg per day was categorised as: 0 mg OME/day, 1-49 mg OME/day (reference), 50-89 mg OME/day, 90-199 mg OME/day and 200mg+ OME/day. Patient risk factors included: age, gender, substance use, mental health history and pain-related factors. Main outcomes included: Prescribed Opioids Difficulties Scale (PODS), Opioid-Related Behaviours In Treatment (ORBIT) scale, and ICD-10 opioid dependence. Multiple confounders for problematic opioid behaviours were assessed. FINDINGS: Of 1,514 participants 44.4% were male (95%CI 41.9-46.9) and their mean age was 58 years (IQR 48-67). Participants had a mean duration of pain of 10 years (IQR 4.5-20.0) and had been taking strong opioids for a median of four years (IQR 1.0-10.0). At baseline, median OME/day was 73 (IQR 35-148). At 5-years, 85% were still taking strong opioids. PODS moderate-high scores reduced from 59.9% (95%CI 58.8-61.0) at baseline to 51.5% (95%CI 50.0-53.0) at 5-years. Around 9% met criteria for ICD-10 opioid dependence at each wave. In adjusted mixed effect models, the risk factors most consistently associated with problematic opioid use were: younger age, substance dependence, mental health histories and higher opioid doses. INTERPRETATION: Both patient risk factors and opioid dose are associated with problematic opioid use behaviours.