National trends in the use of partial nephrectomy: a rising tide that has not lifted all boats.

PURPOSE: Treatment of organ confined renal masses with partial nephrectomy has durable oncologic outcomes comparable to radical nephrectomy. Partial nephrectomy is associated with lower risk of chronic kidney disease and in some series with better overall survival. We report a contemporary analysis on national trends of partial nephrectomy use to determine partial nephrectomy use over time, and whether nontumor related factors such as structural attributes of the treating institution or patient characteristics are associated with the underuse of partial nephrectomy.
MATERIALS AND METHODS: We performed an analysis of the NIS (National Inpatient Sample), which contains 20% of all United States inpatient hospitalizations. We included patients who underwent radical or partial nephrectomy for a renal mass between 2002 and 2008. Survey weights were applied to obtain national estimates of nephrectomy use and to evaluate nonclinical predictors of partial nephrectomy.
RESULTS: A total of 46,396 patients were included in the study for a weighted sample of 226,493. There was an increase in partial nephrectomy use from 15.3% in 2002 to 24.7% in 2008 (p <0.001). On multivariate analysis hospital attributes (urban teaching status, nephrectomy volume, geographic region) and patient socioeconomic status (higher income ZIP code and private/HMO payer) were independent predictors of partial nephrectomy use.
CONCLUSIONS: Since 2002 the national use of partial nephrectomy for the management of renal masses has increased. However, the adoption of partial nephrectomy at smaller, rural and nonacademic hospitals lags behind that of larger hospitals, urban/teaching hospitals and higher volume centers. A lower rate of partial nephrectomy use among patients without private insurance and those living in lower income ZIP code areas highlights the underuse of partial nephrectomy as a quality of care concern.