Patterns of opioid dispensing and associated wage replacement duration in workers with accepted claims for low back pain: a retrospective cohort study.

This study aimed to identify patterns of opioid dispensing in Australian workers with low back pain (LBP) and determine the association of dispensing patterns with wage replacement duration. Australian workers' compensation claimants with LBP and at least 1 day of wage replacement were included. We used group-based trajectory modelling to identify opioid dispensing patterns over a two-and-a-half-year period from reported LBP onset and quantile regression to compare wage replacement duration between each dispensing pattern group. Opioids were dispensed to one-third of workers with LBP (N = 3205, 33.3%) at least once during their claim. Three dispensing patterns were identified. Most had a short-term low-volume opioid dispensing pattern (N = 2166, 67.6%), whereas 798 (24.9%) had a long-term moderate-volume pattern and 241 (7.5%) had a long-term high-volume pattern. Workers with dispensed opioids had significantly longer wage replacement duration than those without dispensed opioids (median [weeks]: 63.6 vs 7.1, respectively). In addition, moderate-volume and high-volume long-term dispensing groups had significantly longer wage replacement duration compared with the short-term dispensing group (median [weeks]: 126.9, 126.0, and 30.7, respectively). Without controlling for pain severity, these results offer limited evidence that opioids lead to longer wage replacement duration. Further research controlling for pain severity, psychosocial factors, and recovery expectations is required to confirm whether the relationship between opioid dispensing pattern and wage replacement duration is causal in nature.