Morphine Equivalent Dose-Days (MED-D): Predicting the Impact of Opioid Prescription on Total Workers' Compensation Claim Costs for Acute Low Back Pain.

OBJECTIVE To assess the effect of morphine equivalent dose-days (MED-D) on the total cost for acute low back pain (LBP) workers' compensation claims. METHODS Simple random samples of 123 opioid and 141 non-opioid acute LBP claims were obtained. Opioid claims were divided into low, medium, and high subgroups for MED-D, MED, and prescription duration. Subgroup mean total costs were compared to the non-opioid group using multivariate regression analyses. RESULTS MED-D and prescription duration were each respectively associated with significantly increased total costs at both medium and high levels. Increasing MED had a negative association with total cost, though stratification by duration abrogated this perceived trend. Interaction testing indicated MED and duration together better explained cost than MED alone. CONCLUSION MED-D is a better predictor of total cost in acute LBP claims than MED alone.