1. Regionalization of Renal Surgery: Impact of Hospital Volume on Utilization of Partial Nephrectomy Marc C. Smaldone 1, Jay Simhan 1, Daniel Canter 2, Russell Starkey 3, Fang Zhu 1, Karyn Stitzenberg 4, Alexander Kutikov 1, Robert G. Uzzo 1 1 Fox Chase Cancer Center, Philadelphia, PA, 2 Emory University, Atlanta, GA, 3 Thomas Jefferson University, Philadelphia, PA, 4 University of North Carolina, Chapel Hill, NC Abstract Introduction and Objectives: In an effort the reduce the risk of chronic kidney disease and its attendant cardiovascular and mortality risks, the AUA guidelines recommend nephron sparing surgery for all localized lesions amenable to partial nephrectomy. The purpose of this study was to investigate trends in regionalization of care for surgical management of renal cell carcinoma (RCC). Methods: Using 1996 to 2009 hospital discharge data from NY, NJ, and PA, patients undergoing surgery for RCC were identified using ICD-9 coding. We assigned hospital volume status by quintiles based on relative proportions of renal procedures (radical nephrectomy, partial nephrectomy, ablation) performed on a per hospital basis in 1996; very low volume hospital: 0-6 (VLVH), low: 7-12 (LVH), moderate: 13-20 (MVH), high: 21-46 (HVH) and very high volume hospital: ≥47 (VHVH). Procedure performance by hospital volume status was assessed over time using regression models and patient characteristics were compared between groups. Results: Of 58,157 patients identified, there was a significant shift towards regionalization for total renal procedures to VHVH’s (18 to 48%, p<0.001) from 1996 to 2009. Patients treated at a VHVH were less likely to be older (ages 65-74 (OR 0.89 [CI 0.82-0.96]); 75-84 (OR 0.89 [CI 0.84- 0.96]), have Medicaid (OR 0.68 [0.50-0.91]), Medicare (OR 0.88 [0.82-0.94]), or be uninsured (OR 0.39 [CI 0.30-0.51]). Over the duration of the study period, partial nephrectomy treatment increased from 8.3% (1996) to 35.4% (2009). Adjusting for confounders, use of radical nephrectomy significantly decreased across volume strata compared to VLVH (all p values <0.001), while trends in use of ablation were less affected by volume status. A significant trend towards increased utilization of partial nephrectomy was observed with increasing volume status; LVH (OR 1.3 [CI 1.1-1.6]), MVH (OR 1.7 [CI 1.5-1.9]), HVH (OR 2.2 [CI 1.9-2.5]), VHVH (OR 4.3 [CI 4.0-4.6]). Conclusions: While increasing overall, performance of partial nephrectomy has shifted to higher volume hospitals from 1996 to 2009. Inequities in access to care exist and must be addressed in future studies. Data Analysis Group characteristics stratified by procedure and volume were compared using chi square analyses. Proportion of procedures performed by volume status were compared between 1996 and 2009. Multivariate logistic regression models: provided estimates of the odds of undergoing any renal procedure or individual procedures (nephrectomy, partial nephrectomy, ablation) in each volume category controlling for demographics, year treated, and total number of procedures. tested associations between patient characteristics and volume category controlling for year treated and total number of procedures performed Methods We used hospital discharge data (1996-2009) from NY, NJ, and PA provided by Databay resources From 1996-1999, only NY and PA data were available Using ICD-9 coding, all patients ≥18 years undergoing renal procedures (nephrectomy, partial nephrectomy, ablation) for renal cell carcinoma (RCC) were identified Hospitals were ranked by number of renal procedures performed in 1996 Using 1996 rankings, five equally proportioned volume groups were determined by total annual renal procedures performed (quintiles) Very low (VLVH): 0-6; Low (LVH): 7-12; Medium (MVH): 13-20; High (HVH): 21-46; Very high (VHVH): ≥47 Cut points were applied to each subsequent year to determine regionalization trends by volume category Results Figure 1. Number of renal procedures/hospital by year Introduction The AUA Guidelines recommend that nephron sparing surgery should be considered in all appropriate surgical candidates with a clinical T1 renal mass presuming that adequate oncologic control can be achieved 1. Performance of nephron sparing surgery has been proposed as a candidate quality of care indicator 2. Hospital and surgeon volume has been associated with improved morbidity & mortality outcomes following cancer surgery 3-4. Centralization over time to high volume hospitals has been demonstrated in non-genitourinary malignancies but have been poorly characterized for urologic cancers 5-6. Use of hospital claims data affords the opportunity to assess regionalization trends in procedure performance over time. Characteristic Total N = 58,157 RN N = 42,516 PN N = 13,239 ABL N = 2,402 P Value N (%) Age (years) <0.0001 <5515,775 (27.3)11,099 (26.1)4,307 (32.5)466 (19.4) ≥55 to <6514,936 (25.8)10,701 (25.2)3,740 (28.3)555 (23.1) ≥65 to <7515,719 (27.2)11,587 (27.3)3,528 (26.7)668 (27.9) ≥75 to <8510,193 (17.6)8,071 (19.0)1,563 (11.8)602 (25.1) ≥851263 (2.2)1,058 (2.5)101 (0.8)110 (4.6) Race <0.0001 Caucasian45,665 (78.9)33,687 (79.2)10,324 (78.0)1,868 (78.8) African American 5,285 (9.1)3,843 (9.0)1,208 (9.1)254 (10.6) Other6,691 (11.6)4,877 (11.5)1,581 (11.9)270 (11.2) Unknown245 (0.4)109 (0.3)126 (1.0)10 (0.4) Gender <0.0001 Female22,256 (38.5)16,671 (39.2)4,750 (35.9)950 (39.6) Male35,630 (61.6)25,845 (60.8)8,489 (64.1)1,452 (60.5) Payer Group <0.0001 Private27,749 (47.9)19,605 (46.1)7,325 (55.3)945 (39.3) Medicare25,310 (43.7)19,369 (45.6)4,753 (35.9)1,299 (54.1) Medicaid3,280 (5.7)2,338 (5.5)851 (6.4)109 (4.5) Uninsured887 (1.5)694 (1.6)178 (1.3)22 (0.9) Unknown660 (1.1)510 (1.2)132 (1)27 (1.1) RN – radical nephrectomy, PN – partial nephrectomy, ABL - ablation Table I. Characteristics of Patients Undergoing Renal Surgery from 1995- 2009 By Procedure Type * * * * * * p<0.0001 1996 2009 Figure 2. Proportion of Renal Procedures By Volume Strata (1996 & 2009) Characteristic VLVH N = 7,187 LVH N = 8,885 MVH N = 8,554 HVH N = 14,007 VHVH N = 19,524 P Value N (%) Age (years) <0.0001 <551,823 (25.4)2,212 (24.9)2,223 (26.0)3,877 (27.7)5,737 (29.4) ≥55 to <651,717 (23.9)2,137 (24.1)2,151 (25.2)3,675 (26.2)5,316 (27.2) ≥65 to <751,946 (27.1)2,570 (28.9)2,398 (28.0)3,699 (26.4)5,171 (26.5) ≥75 to <851,519 (21.1)1,729 (19.5)1,603 (18.7)2,430 (17.4)2,955 (15.1) ≥85182 (2.5)237 (2.7)179 (2.1)326 (2.3)345 (1.8) Race <0.0001 Caucasian5,656 (78.7)7,186 (80.9)6,577 (76.9)10,677 (76.2)15,783 (80.8) African American 765 (10.6)878 (9.9)965 (11.3)1,213 (8.7)1,484 (7.6) Other763 (10.6)808 (9.1)894 (14.5)2,011 (14.4)2,252 (11.5) Unknown3 (0.04)13 (0.2)118 (1.4)106 (0.8)5 (0.03) Gender <0.0001 Female2,939 (40.9)3,556 (40.0)3,384 (39.6)5,349 (38.2)7,143 (36.6) Male4,248 (59.1)5,329 (60.0)5,170 (60.4)8.658 (61.8)12,381 (63.4) Payer Group <0.0001 Private2,919 (40.6)3,959 (44.6)3,907 (45.7)6,763 (48.3)10,327 (52.9) Medicare3,378 (47)4,157 (46.8)3,859 (45.1)6,130 (43.8)7,897 (40.5) Medicaid553 (7.7)455 (5.1)534 (6.2)773 (5.5)983 (5.0) Uninsured212 (3.0)170 (1.9)158 (1.9)169 (1.2)185 (1.0) Unknown125 (1.7)144 (1.6)96 (1.1)172 (1.2)132 (0.7) VLVH – very low volume hospital, LVH – low volume hospital, MVH – medium volume hospital, HVH – high volume hospital, VHVH – very high volume hospital Table II. Characteristics of Patients undergoing Renal Surgery from 1995- 2009 by Volume Category Very Low Volume HospitalVery High Volume Hospital CovariateOR [CI]CovariateOR [CI] Year Treated0.89 [0.88-0.91]Year Treated1.15 [1.1-1.2] Age (years) ≥65 to <751.06 [1.04-1.08] ≥65 to <750.89 [0.82-0.96] ≥75 to <851.32 [1.2-1.5] ≥75 to <850.89 [0.84-0.96] Race Gender African American1.36 [1.1-1.8] Male1.07 [1.03-1.11] Gender Payer Group Male0.94 [0.92-0.96] Medicaid0.68 [0.5-0.9] Payer Group Medicare0.88 [0.8-0.9] Medicaid1.81 [1.3-2.5] Uninsured0.39 [0.3-0.5] Medicare1.15 [1.1-1.2] Uninsured2.82 [1.7-4.6] OR – odds ratio, CI – confidence interval Controlling for year treated, total number of procedures, age, race, gender, payer group Table III. Patient Characteristics Associated with Treatment at Very Low Volume and Very High Volume Hospitals Figure 3. Renal Procedures By Type Stratified By Hospital Volume (1996-2009) Hospital VolumeRadical NephrectomyPartial NephrectomyAblation Odds Ratio [Confidence Interval] VLVH (reference) LVH0.77 [0.7-0.9]1.34 (1.1-1.6]1.12 [1.10-1.14] MVH0.60 [0.5-0.7]1.72 [1.5-1.9] HVH0.48 [0.4-0.6]2.15 [1.9-2.5]1.53 [1.2-1.9] VHVH0.26 [0.2-0.3]4.30 [4.0-4.6] VLVH – very low volume hospital, LVH – low volume hospital, MVH – medium volume hospital, HVH – high volume hospital, VHVH – very high volume hospital Controlling for year treated, total number of procedures, age, race, gender, payer group Table IV. Association Between Hospital Volume Category and Year Treated By Procedure Type Limitations Lack of patient specific co-morbidity, pathologic, & complications data. Our sample may not be generalizable to larger populations due to geographic influences. Definition of hospital volume status does not specifically account for change in annual number of procedures performed. Conclusions These data demonstrate that there has been extensive regionalization of renal procedures to VHVH’s from 1996-2009. While the proportion of partial nephrectomies performed has increased across all volume strata over time, utilization of partial nephrectomy has increased most dramatically at very high volume centers. Disparities in access to higher volume hospitals were evident in our cohort which should be the focus of further investigation. References 1.Campbell SC, Novick AC, Belldegrun A, et al: Guideline for management of the clinical T1 renal mass. J Urol 182:1271-9, 2009 2.Hollenbeck BK, Taub DA, Miller DC, et al: National utilization trends of partial nephrectomy for renal cell carcinoma: a case of underutilization? Urology 67:254-9, 2006 3.Birkmeyer JD, Siewers AE, Finlayson EV, et al. Hospital volume and surgical mortality in the United States. NEJM (2002); 346: 1128-1137. 4.Hollenbeck BK, Dunn RL, Miller DC, et al. Volume based referral for cancer surgery: Informing the debate. J Clin Oncol (2007); 25 (1): 91-96. 5.Stitzenberg KB, Sigurdson ER, Egleston BL, et al. Centralization of cancer surgery: implications for patient access to optimal care. J Clin Oncol (2009); 27 (28): 4671-8. 6.Stitzenberg KB, Wong YN, Nielsen ME, et al. Trends in radical prostatectomy: centralization, robotics, and access to urologic cancer care. Cancer (2011); epub ahead of print. Funded by Fox Chase Cancer Center via institutional support of the Kidney Cancer Keystone Program Abstract #425