The Relationship Between Medicare Outpatient Efficiency Measure OP8 and Lumbar MRI Utilization.

Introduction: Quality-based reporting and payment are predicated on using valid metrics. We sought to determine the relationship between widely used lumbar imaging quality metric OP8 and underlying quality as measured through actual utilization of lumbar MRI.

Methods: We performed a multi-institutional cross-sectional study using hospital-level billing data from a major commercial insurance company, including 23 Washington State hospitals from July 1, 2014, to June 30, 2015, with more than 25 eligible visits. For each hospital, we determined the OP8 score using the CMS published specifications. We calculated actual utilization rate from the proportion of patients visiting primary care (internal medicine or family medicine, including physicians, nurse practitioners, and physician assistants) for uncomplicated low back pain who underwent lumbar MRI. For both measures, patients under age 18 or with complicated conditions (eg, infection, cancer, inflammatory arthropathy) were excluded. OP8 scores and utilization were compared using linear regression and correlation coefficients.

Results: Hospital scores ranged from 28.0% to 55.3% on OP8 and from 0.7% to 4.2% on MRI utilization (with lower scores indicating better performance). There was no association between score on OP8 and actual utilization of lumbar MRI across hospitals in Washington State (attributable risk 0.00016, 95% confidence interval: -0.00026, 0.00059, P = .43).

Discussion: Widely used imaging efficiency measure OP8 does not correlate with actual utilization of lumbar MRI. Better OP8 scores reflect use of antecedent conservative therapy regardless of whether MRI is overutilized. OP8 scores may be worse for institutions with aggressive control of inappropriate imaging.