Effectiveness of Long-Term Opioid Therapy for Chronic Low Back Pain

Purpose: Clinical trials generally have not assessed efficacy of long-term opioid therapy (LTOT) beyond 6 months because of methodological barriers and ethical concerns. We aimed to measure the effectiveness of LTOT for up to 12 months. Methods: We conducted a retrospective cohort study among adults with chronic low back pain (CLBP) from April 2016 through August 2022. Participants reporting LTOT (>90 days) were matched to opioid nonusers with propensity scores. Primary outcomes involved low back pain intensity, back-related disability, and pain impact measured with a numerical rating scale, the Roland-Morris Disability Questionnaire, and the Patient-Reported Outcomes Measurement Information System, respectively. Secondary outcomes involved minimally important changes in primary outcomes. Results: The mean age of 402 matched participants was 55.4 years (S.D., 11.9 years), and 297 (73.9%) were female. There were 119 (59.2%) LTOT users who took opioids continuously for 12 months. The mean daily morphine milligram equivalent dosage at baseline was 36.7 (95% CI, 32.8 to 40.7). There were no differences between LTOT and control groups in mean pain intensity (6.06, 95% CI, 5.80-6.32 vs 5.92, 95% CI, 5.68-6.17), back-related disability (15.32, 95% CI, 14.55-16.09 vs 14.81, 95% CI, 13.99-15.62), or pain impact (32.51, 95% CI, 31.33-33.70 vs 31.22, 95% CI, 30.00 to 32.43). Correspondingly, LTOT users did not report greater likelihood of minimally important changes in any outcome. Conclusions: Using LTOT for up to 12 months is not more effective in improving CLBP outcomes than treatment without opioids. Clinicians should consider tapering opioid dosage among LTOT users in accordance with clinical practice guidelines.