Disparities in Access to Outpatient Surgery Related to Removal of Procedures from Medicare's Inpatient Only List.

OBJECTIVE: We assessed the shift from inpatient to outpatient surgical care related to changes to the Inpatient Only List in 2020 and 2021 compared to 2019.

SUMMARY BACKGROUND DATA: The extent to which procedures shift from the inpatient to outpatient setting following removal from Medicare's Inpatient Only List is unknown. Many health systems also encouraged a shift from inpatient to outpatient surgery during the COVID-19 pandemic. Assessing the relative change in outpatient surgical utilization for procedures removed from the Inpatient Only List during COVID-19 would provide empirical data on whether reimbursement policy changes or inpatient capacity needs during the pandemic were more likely to shift care from the inpatient to outpatient setting.

METHODS: We used administrative data from the PINC AI Healthcare Database across 723 hospitals to determine the within-facility relative change in outpatient vs inpatient procedural volume in 2020 and 2021 compared to 2019 using a multivariable conditional fixed-effects Poisson regression model. We also assessed whether outpatient surgical utilization varied by race and ethnicity. Using a multivariable linear probability model, we assessed the absolute change in risk-adjusted 30-day complication, readmission, and mortality rates for inpatient and outpatient surgical procedures.

RESULTS: In 2020 and 2021 compared to 2019 respectively, there was a 5.3% (95% CI, 1.4% to 9.5%) and 41.3% (95% CI 33.1% to 50.0%) relative increase in outpatient elective procedural volume. Outpatient procedural volume increased most significantly for hip replacement which was removed from the Inpatient Only List in 2020 (increase in outpatient surgical utilization of 589.3% (95% CI, 524.9% to 660.3%)). The shift to outpatient hip replacement procedures was concentrated among White patients; in 2021, hip replacement procedural volume increased by 271.1% (95% CI, 241.2% and 303.7%) for White patients and 29.5% (95% CI, 24.4% and 34.9%) for Black patients compared to 2019 levels. There were no consistent or large changes in 30-day complication, readmission, or mortality risk in 2020 and 2021 compared to 2019.

CONCLUSION: There was a modest increase in elective outpatient surgeries and a pronounced increase in outpatient orthopedic surgeries which were removed from the Inpatient Only List during the COVID-19 pandemic. Utilization of outpatient surgical procedures was concentrated among White patients.