Simulated Volume-Based Regionalization of Complex Procedures: Impact on Spatial Access to Care.

Objective: This study simulates the regionalization of pancreatectomies to assess its impact on spatial access in terms of patient driving times.

Background: Although policies to regionalize complex procedures to high-volume centers may improve outcomes, the impact on patient access is unknown.

Methods: Patients who underwent pancreatectomies from 2005 to 2014 were identified from California's statewide database. Round-trip driving times between patients' home ZIP code and hospital addresses were calculated via Google Maps. Regionalization was simulated by eliminating hospitals performing <20 pancreatectomies/yr, and reassigning patients to the next closest hospital that satisfied the volume threshold. Sensitivity analyses were performed for New York and Medicare patients to assess for influence of geography and insurance coverage, respectively.

Results: Of 13,317 pancreatectomies, 6335 (47.6%) were performed by hospitals with <20 cases/yr. Patients traveled a median of 49.8 minutes [interquartile range (IQR) 30.8-96.2] per round-trip. A volume-restriction policy would increase median round-trip driving time by 24.1 minutes (IQR 4.5-53.5). Population in-hospital mortality rates were estimated to decrease from 6.7% to 2.8% (P < 0.001). Affected patients were more likely to be racial minorities (44.6% vs 36.5% of unaffected group, P < 0.001) and covered by Medicaid or uninsured (16.3% vs 9.8% of unaffected group, P < 0.001). Sensitivity analyses revealed a 17.8 minutes increment for patients in NY (IQR 0.8-47.4), and 27.0 minutes increment for Medicare patients (IQR 6.2-57.1).

Conclusions: A policy that limits access to low-volume pancreatectomy hospitals will increase round-trip driving time by 24 minutes, but up to 54 minutes for 25% of patients. Population mortality rates may improve by 1.5%.