Study design: Retrospective cohort study of workers' compensation (WC) claims with acute disabling low back pain (LBP).
Objective: To examine the association between early opioid use for acute LBP and outcomes: disability duration, medical costs, "late opioid" use (> or = 5 prescriptions from 30 to 730 days), and surgery in a 2-year period following LBP onset.
Summary of background data: Opioid analgesics have become more accepted for acute pain management. However, treatment guidelines recommend limited opioid use for acute LBP management. Little is known about the long-term impact on outcomes of opioid use for acute LBP.
Methods: The sample consisted of 8443 claimants from a large WC database with new-onset, disabling LBP that occurred between January 1, 2002 and December 31, 2003. Based on morphine equivalent amount (MEA) in milligrams received in the first 15 days ("early opioids"), claimants were divided into 5 groups (0, 1-140, 141-225, 226-450, 450+). The associations between early opioids and outcomes were evaluated using multivariate linear and logistic regression models. Covariates included age, gender, job tenure, and low back injury severity. Injury severity was classified using ICD-9 codes.
Results: Twenty-one percent of claimants received at least 1 early opioid prescription. After controlling for the covariates, mean disability duration, mean medical costs, and risk of surgery and late opioid use increased monotonically with increasing MEA. Those who received more than 450 mg MEA were, on average, disabled 69 days longer than those who received no early opioids (95% confidence interval [CI], 49.2-88.9). Compared with the lowest MEA group (0 mg opioid), the risk for surgery was 3 times greater (95% CI, 2.4-4.0) and the risk of receiving late opioids was 6 times greater (95% CI, 4.9-7.7) in the highest MEA group. Low back injury severity was a strong predictor of all the outcomes.
Conclusion: Given the negative association between receipt of early opioids for acute LBP and outcomes, it is suggested that the use of opioids for the management of acute LBP may be counterproductive to recovery.