The effect of the diffusion of the Surgical Robot on the hospital-level utilization of partial nephrectomy

Purpose. The rapid diffusion of the surgical robot has been fraught with controversy because of the technology’s high costs and controversial disputed marginal benefit. Some have suggested that adoption of the surgical robot has facilitated partial nephrectomy for renal malignancy, an underutilized procedure considered to be more challenging yet less morbid than radical nephrectomy. We sought to determine whether institutional acquisition of the surgical robot was associated with a higher local rate of partial nephrectomy.

Methods. We used the 2001, 2005 and 2008 Health-care Cost and Utilization Project State In-patient Databases from 7 states to identify 21,569 surgical procedures for renal tumors. These patient-level records were aggregated to the hospital-level then merged with the American Hospital Association Survey and with publicly available data on timing of surgical robot acquisitiondocumenting whether and when a surgical robot was acquired by that hospital. We used a difference-in-difference model to assess at the hospital-level whether robot acquisition was associated with an increase in the rate of partial nephrectomy, adjusting for total nephrectomy rate, year of surgery, year of robot acquisition, state  and several hospital-level factors. We also performed two sensitivity analyses to determine whether there was a time lag between robot acquisition and the development of surgical expertise to perform partial nephrectomy (because of a presumed necessity to develop requisite surgical skill) and to ensure that there was no association between robot acquisition and performance of an unrelated procedure (the presence of which might suggest unmeasured confounding, rather than robot acquisition as the cause for increased surgical volume).

Results. In the multivariable adjusted differences-in-differences model (Figure 1), hospits acquiring al robot acquisition in the time period between 2001-2005 performed more was significantly associated with increased utilization of partial nephrectomiesy in both2005 (31% increase) and 2008 (36% total increase) (p<0.01 for both). Hospitals that acquiringed the a surgical robot in the time period between 2005-2008 also demonstrated higher rates of partial nephrectomy 2008 (16% increase) (p=0.02). Results of the secondary lag time analysis were not substantially different from the primary analysis. There was no association between robot acquisition and utilization of an unrelated surgical procedure.

Conclusion. Hospital acquisition of the surgical robot is associated with increased utilization of partial nephrectomy, an underutilized, guideline-encouraged procedure. This is one of the few studies to suggest acquisition of the surgical robot was associated with improvement in quality of patient care.