OBJECTIVES: This study aimed to compare direct healthcare costs and opioid use over a 1-year period following initiation with duloxetine versus other standard of care (SOC) treatments among patients with chronic low back pain (CLBP). METHODS: This retrospective cohort study assessed commercially-insured Marketscan CLBP patients aged 18-64 years who initiated duloxetine or other treatments (tricyclic antidepressants, venlafaxine, pregabalin, gabapentin, muscle relaxants and opioids) in 2009. The first dispense date was defined as the index date. Selected patients were required to have at least two low back pain (LBP) inpatient or outpatient claims with at least 90 days gap between the 2 in the 12-month pre-index period. Both duloxetine and SOC cohorts were then matched via propensity scoring (n=668 for each cohort), controlling for demographics, comorbidities, prior healthcare utilization and costs, and prior medication history. Health care costs and opioid use (among patients not initiated on opioids) over the 12-month post-index period were compared between cohorts. RESULTS: Total health care costs over the 12-month post-index period were $17,435 among duloxetine-initiated patients, versus $19,633 (p=0.1781) for SOC-initiated patients.  Duloxetine-initiated patients also had significantly lower inpatient costs ($3,486 vs. $5,975, p=0.0219). While both groups had similar outpatient costs ($9,558 vs. $10,424, p=0.3324), CLBP-related outpatient costs were significantly lower among duloxetine-initiated patients ($1,042 vs. $1,593, p=0.0034). The pharmacy costs were, however, higher in these patients, compared to SOC-initiated patients ($4,358 vs. $3,235, p<0.001). In addition, duloxetine-initiated patients were less likely to use any opioids (56% vs. 63%, p<0.05) compared with SOC patients not initiated on opioids. CONCLUSIONS: Commercially-insured CLBP patients initiating duloxetine were associated with significantly lower inpatient costs and CLBP-related outpatient costs, but higher pharmacy costs, compared to patients initiating other SOC treatments. Duloxetine-initiated patients were also less likely to use opioids in the post-index year.