Performance of Neurosurgeons Providing Safety-Net Care Under Medicare's Merit-Based Incentive Payment System

BACKGROUND AND OBJECTIVES: Under the Merit-Based Incentive Payment System (MIPS), Medicare evaluates provider performance to determine payment adjustments. Studies examining the first year of MIPS (2017) showed that safety-net providers had lower MIPS scores, but the performance of safety-net physicians over time has not been studied. This study aimed to examine the performance of safety-net vs non-safety-net neurosurgeons in MIPS from 2017 to 2020. METHODS: Safety-net neurosurgeons were defined as being in the top quartile according to proportion of dual-eligible beneficiaries and non-safety-net in the bottom quartile. Outcomes were total MIPS scores and dual-eligible proportion over time. In this descriptive study, we evaluated ordinary least squares regression models with SEs clustered at the physician level. Covariates of interest included safety-net status, year, and average Hierarchical Condition Category risk score of beneficiaries. RESULTS: There were 2796-3322 physicians included each year between 2017 and 2020. Mean total MIPS scores were not significantly different for safety-net than non-safety-net physicians in 2017 but were greater for safety-net in 2018 (90.7 vs 84.5, P < .01), 2019 (86.4 vs 81.5, P < .01), and 2020 (90.9 vs 86.7, P < .01). Safety-net status (coefficient -9.11; 95% CI [-13.15, -5.07]; P < .01) and participation in MIPS as an individual (-9.89; [-12.66, -7.13]; P < .01) were associated with lower scores while year, the interaction between safety-net status and year, and participation in MIPS as a physician group or alternative payment model were associated with higher scores. Average Hierarchical Condition Category risk score of beneficiaries (-.011; [-.015, -.006]; P < .01) was associated with decreasing dual-eligible case mix, whereas average age of beneficiaries (.002; [.002, .003]; P < .01) was associated with increasing dual-eligible case mix. CONCLUSION: Being a safety-net physician was associated with lower MIPS scores, but safety-net neurosurgeons demonstrated greater improvement in MIPS scores than non-safety-net neurosurgeons over time. Providers with higher-risk patients were more likely to decrease their dual-eligible case mix over time.