Early Advanced Imaging among Washington State Workers' Compensation Claimants with Non-Specific Acute Occupational Low Back Pain: An Evaluation of Precursors, Costs, Utilization, and Outcomes

Early use of advanced diagnostic imaging for non-specific, acute low back pain (LBP) is associated with increased healthcare utilization and costs, yet does not contribute to improved medical management or health outcomes for patients. Evidence-based guidelines recommend use of magnetic resonance imaging (MRI) within the first six weeks of symptoms for acute LBP only among patients with characteristics that may indicate neurological impairment or serious underlying conditions. Other patients should be treated conservatively, only receiving imaging if symptoms persist beyond six weeks. For workers' compensation programs, adherence to these guidelines is important to avoid mis- and overuse of imaging for LBP, which is a common and costly occupational condition. This dissertation describes three population-based, prospective cohort studies of workers' compensation claimants with acute occupational LBP in Washington State. The first study assessed the factors associated with receiving early MRI and found that workers who were male or whose initial office visit was with a surgeon were more likely to receive early MRI. Workers with elevated work fear-avoidance, higher Roland scores, or increased injury severity were more likely to receive early imaging than counterparts with lower levels or scores. The second study evaluated the impact of early imaging on the utilization and cost of healthcare in the year following imaging. Results showed that workers with early MRI were less likely to have subsequent advanced imaging, more likely to have outpatient visits, and had higher adjusted mean costs for outpatient and inpatient care, disability compensation, and other workers' compensation expenses. The third study evaluated the effect of early imaging on health outcomes 1 year after imaging. Results showed that imaging was not associated with 1-year health outcomes but was associated with an increased likelihood of long-term disability for workers with mild/major sprains. Early MRI was associated with longer disability duration for all workers. Occupational LBP is a multi-factorial, complex condition. Early MRI plays an important role in its diagnosis, but inappropriate use may have deleterious consequences that could be avoided through adherence to evidence-based guidelines.