Effects and costs of a group-based educational intervention to reduce opioid use in people with chronic pain: I-wotch Rct

BACKGROUND: The long-term use of strong opioids for chronic non-cancer pain puts people at risk of serious harm. OBJECTIVES: To test the effectiveness and cost-effectiveness of a multicomponent intervention targeting opioid use for the treatment of chronic pain. DESIGN: A multicentred randomised controlled trial with embedded process evaluation. SETTING: Primary care. PARTICIPANTS: Adults using strong opioids for non-malignant chronic. INTERVENTIONS: Participants were randomised 1 : 1 (using a minimisation programme stratified by geographical locality, baseline pain intensity score and baseline morphine equivalent dose) to either usual care (an educational booklet and relaxation compact disc) or usual care plus the I-WOTCH intervention; 3 day-long group sessions delivered by a nurse and lay facilitator, plus a one-to-one session and ongoing telephone contact from the nurse to support opioid tapering. MAIN OUTCOME MEASURES: The two primary outcomes were Patient-Reported Outcomes Measurement Information System Pain Interference Short Form (8A), and proportion using no opioids, at 12 months. RESULTS: We randomised 608 people. At 12 months, there was no between-group difference in Patient-Reported Outcomes Measurement Information System Pain Interference Short Form (8A) scores; mean difference, -0.52 (95% confidence interval -1.94 to 0.89). At 12 months, 65/225 (29%) of people in the intervention group and 15/208 (7%) of people in usual-care group reported using no opioids [odds ratio 5.55 (95% confidence interval 2.80 to 10.99)], absolute difference, 21.7% (95% confidence interval 14.8 to 28.6). Over a lifetime horizon, I-WOTCH is on average associated with an incremental cost of £9277 per person, and provides an additional 0.314 quality-adjusted life-years. The deterministic incremental cost per quality-adjusted life-year gained was £29,543. The I-WOTCH intervention may be cost-effective compared to best usual care. The process evaluation suggested group support and shared experience were important to those trying to taper. LIMITATIONS: The opioid use analysis is based solely on participant self-report. The findings only apply to people willing to consider opioid reduction and may not apply to a more complex secondary care population. The results may not be applicable to people using very high opioid doses. CONCLUSIONS: The I-WOTCH intervention helps substantially more people stop opioids than best usual care without adversely affecting pain interference. FUTURE WORK: The I-WOTCH intervention should be tested in different healthcare settings and other populations. TRIAL REGISTRATION: This trial is registered as Current Controlled Trials ISRCTN49470934. FUNDING: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 14/224/04) and is published in full in Health Technology Assessment; Vol. 30, No. 35. See the NIHR Funding and Awards website for further award information.