The effect of long-term opioid use on back-specific disability and health-related quality of life in patients with chronic low back pain.

CONTEXT

Opioids are commonly utilized for the treatment of chronic pain. However, research regarding the long-term (≥12 months) outcomes of opioid therapy remains sparse.

OBJECTIVES

This study aims to evaluate the effects of long-term opioid therapy on measures of back-specific disability and health-related quality of life in patients with chronic low back pain.

METHODS

In this retrospective cohort study, patients with chronic low back pain who reported consistent opioid use or abstinence for at least 12 months while enrolled in the Pain Registry for Epidemiological, Clinical, and Interventional Studies and Innovation Pain Research Registry were classified as long-term opioid users or nonusers, respectively. For comparison, intermediate-term and short-term opioid users and nonusers were also identified. Multiple linear regression analysis was performed to compare back-specific disability (Roland-Morris Disability Questionnaire [RMDQ]) and health-related quality of life (29-item Patient-Reported Outcomes Measurement Information System [PROMIS]) between opioid users and nonusers while controlling for pain intensity, depression, age, body mass index (BMI), and eight common comorbid conditions (herniated disc, sciatica, osteoporosis, osteoarthritis, heart disease, hypertension, diabetes, and asthma). Statistically significant findings were assessed for clinical relevance.

RESULTS

There were 96 long-term opioid users and 204 long-term opioid nonusers. After controlling for potential confounders, long-term opioid use was a predictor of worse back-specific disability (adjusted mean difference=2.85, p<0.001), physical function (adjusted mean difference=-2.90, p=0.001), fatigue (adjusted mean difference=4.32, p=0.001), participation in social roles (adjusted mean difference=-4.10, p<0.001), and pain interference (adjusted mean difference=3.88, p<0.001) outcomes. Intermediate-term opioid use was a predictor of worse back-specific disability (adjusted mean difference=2.41, p<0.001), physical function (adjusted mean difference=-2.26, p=0.003), fatigue (adjusted mean difference=3.70, p=0.002), and sleep disturbance outcomes (adjusted mean difference=3.03, p=0.004), whereas short-term opioid use was a predictor of worse back-specific disability (adjusted mean difference=2.42, p<0.001) and physical function outcomes (adjusted mean difference=-1.90, p<0.001).

CONCLUSIONS

The findings of this study are largely consistent with existing literature regarding the outcomes of long-term opioid therapy. Taken in conjunction with the well-established risks of opioid medications, these findings draw into question the utility of long-term opioid therapy for chronic low back pain.