URO ONCO

Welcome, this website is intended for all international healthcare professionals in uro-oncology. By clicking the link below you are declaring and confirming that you are a healthcare professional.

You are here

Comparative Analysis of Outcomes and Costs Following Open Radical Cystectomy Versus Robot-Assisted Laparoscopic Radical Cystectomy: Results From the US Nationwide Inpatient Sample

European Urology, 6, 61, pages 1239 - 1244

Abstract

Background

Although robot-assisted laparoscopic radical cystectomy (RARC) was first reported in 2003 and has gained popularity, comparisons with open radical cystectomy (ORC) are limited to reports from high-volume referral centers.

Objective

To compare population-based perioperative outcomes and costs of ORC and RARC.

Design, setting, and participants

A retrospective observational cohort study using the US Nationwide Inpatient Sample to characterize 2009 RARC compared with ORC use and outcomes.

Outcome measurements and statistical analysis

Propensity score methods were used to compare inpatient morbidity and mortality, lengths of stay, and costs.

Results and limitations

We identified 1444 ORCs and 224 RARCs. Women were less likely to undergo RARC than ORC (9.8% compared with 15.5%, p = 0.048), and 95.7% of RARCs and 73.9% of ORCs were performed at teaching hospitals (p < 0.001). In adjusted analyses, subjects undergoing RARC compared with ORC experienced fewer inpatient complications (49.1% and 63.8%, p = 0.035) and fewer deaths (0% and 2.5%, p < 0.001). RARC compared with ORC was associated with lower parenteral nutrition use (6.4% and 13.3%, p = 0.046); however, there was no difference in length of stay. RARC compared with ORC was $3797 more costly (p = 0.023). Limitations include retrospective design, absence of tumor characteristics, and lack of outcomes beyond hospital discharge.

Conclusions

RARC is associated with lower parenteral nutrition use and fewer inpatient complications and deaths. However, lengths of stay are similar, and the robotic approach is significantly more costly.

Take Home Message

Robot-assisted laparoscopic radical cystectomy is associated with lower parenteral nutrition use and fewer inpatient complications and deaths compared with open radical cystectomy. However, there was no difference in length of stay, and the robotic approach was significantly more costly.

Keywords: Bladder cancer, Cost, Cystectomy, Outcomes, Robotic surgery.

1. Introduction

Despite advances in surgical technique, radical cystectomy remains a morbid procedure, with complications ranging from 30% to 65% [1] and [2]. Many patients intuitively perceive minimally invasive approaches as reducing complications compared with conventional open operations and prefer minimally invasive procedures because of smaller incisions requiring less analgesics and shorter hospital stays, even at greater cost. The robotic surgical platform shortens the learning curve for open surgeons transitioning to minimally invasive surgery [3] . Advantages of robotic technology compared with traditional laparoscopy include a three-dimensional view of the operative field and the absence of a fulcrum effect with seven compared with four degrees of freedom of wristed instrument movement, which increases the ease of intracorporeal suturing, eliminates surgeon tremor, and provides ergonomic benefits. Thus the robotic surgical platform facilitates a minimally invasive approach to radical cystectomy.

Despite the technical advantages of robotic technology, there are few comprehensive comparative studies of robot-assisted laparoscopic radical cystectomy (RARC) and open radical cystectomy (ORC). To date, the largest series compared 104 ORCs with 83 RARCs and demonstrated fewer complications with the robotic approach [4] , and the only randomized study, comparing 20 ORCs with 21 RARCs, found lower blood loss and analgesic requirements, earlier return to bowel function, and demonstrated comparable lymph node yields [5] . However, most studies, including the aforementioned, arise from high-volume referral centers and may not reflect practice patterns and outcomes generalizable on a population-based level. Therefore, the objectives of our population-based study are to characterize patterns of care and to compare inpatient outcomes and costs of RARC and ORC.

2. Methods

2.1. Data source

Subjects were identified from the US Healthcare Cost and Utilization Project (HCUP) Nationwide Inpatient Sample (NIS), sponsored by the Agency for Healthcare Research and Quality [6] . The NIS is a 20% stratified probability sample that encompasses approximately 8 million acute hospital stays per year from 1050 hospitals in 44 states. It is the largest all-payer inpatient care observational cohort in the United States and represents approximately 90% of all hospital discharges.

2.2. Study cohort

During 2009, there were 7 810 762 subjects within the NIS. Using NIS discharge weights, these subjects represented 39 434 956 admissions. We used the International Classification of Diseases, 9th Revision (ICD-9), procedure code 57.71 associated with bladder cancer (BCa) diagnosis codes 188.0–188.6, 188.8, 188.9, and 233.7 to identify radical cystectomy. The ICD-9 modifier for robotic assistance, 17.4x, initiated on October 1, 2008, was used to identify RARC. Also, concurrent ICD-9 54.21 and 54.51 without a robotic-assistance modifier were used to identify cases of pure laparoscopic radical cystectomy. However, only 55 laparoscopic radical cystectomies were identified, and they were excluded because of inability to power adjusted analyses.

For each procedure, we examined patient- and hospital-level characteristics that may be associated with outcomes. Patient-level characteristics included age, gender, race, number of comorbidities based on the Elixhauser method [7] , ZIP code–based median income, primary payer, and use of ileal conduit or continent (orthotopic neobladder or continent cutaneous reservoir) urinary diversion identified using ICD-9 56.51 or 57.87. Hospital characteristics included non-teaching compared with teaching, bed size, US Census region, and annual radical cystectomy volume.

2.3. Outcomes

Pelvic lymph node dissections were identified using ICD-9 40.3 and 40.5. ICD-9 diagnosis and procedure codes ( Table 1 ) were used to identify blood transfusions, parenteral nutrition use, and inpatient complications (cardiac, respiratory, genitourinary, vascular, wound, miscellaneous medical, and miscellaneous surgical) [8] . NIS-specific outcomes included death, hospital lengths of stay, discharge disposition (routine [home] vs home health care vs other [rehabilitation, skilled nursing facility, and so on]), and total costs. Costs were derived from total hospital charges using the HCUP cost-to-charge ratio, which allows conversion of charges to the amount that hospitals are reimbursed [9] .

Table 1 ICD-9 codes for blood transfusion, parenteral nutrition use, and complications

Category Diagnosis codes Procedure codes
Blood transfusion V58.2 99.00, 99.02, 99.03, 99.04
Parenteral nutrition 99.15
Cardiac 410.xx, 402.01, 402.11, 402.91, 428.xx, 427.5, 997.1
Respiratory 518.0, 514, 518.4, 466.xx, 480.xx, 481, 482.xx, 483.xx, 485, 486, 518.5, 518.81, 518.82, 799.1, 997.3
Genitourinary 590.1x, 590.2, 590.8x, 590.9, 591, 593.3, 593.4, 593.5, 593.81, 593.82, 595.89, 596.1, 596.2, 596.6, 997.5 55.02, 55.03, 55.12, 55.93, 55.94, 59.93, 97.61, 97.62, 56.1, 56.41, 56.74, 56.75, 56.81, 56.84, 56.86, 56.89, 56.91
Wound 567.xx, 998.3, 998.5x, 998.6 54.61, 54.1x, 54.91, 54.0, 59.19
Vascular 415.1, 451.1x, 451.2, 451.81, 451.9, 453.8, 453.9, 997.2, 999.2, 444.22, 444.81, 433.xx, 434.xx, 436, 437.xx
Miscellaneous medical 584.xx, 586, 785.5x, 995.0, 995.4, 998.0, 999.4, 999.5, 999.6, 999.7, 999.8, 457.8, 560.1, 560.8x, 560.9, 997.4, 353.0, 354.2, 723.4, 955.1, 955.3, 955.7, 955.8, 955.9, 531.xx, 532.xx, 533.xx, 782.4, 573.8
Miscellaneous surgical 599.1, 596.1, 596.6, 565.1, 569.3, 569.83, 569.4x, 998.1x, 998.83, 998.9, 998.2, 998.4, 998.7, 604.0, 956.0, 956.1, 956.4, 956.5, 956.8, 956.9, 902.50, 902.51, 902.52, 902.53, 902.54, 902.59 46.03, 46.04, 46.10, 46.11, 46.14, 48.4x, 48.5, 48.6x, 48.7x, 48.9x

ICD-9 = International Classification of Diseases, 9th revision.

2.4. Statistical analysis

Stratification, clustering, and survey weights were used in accordance with the NIS sampling design. Demographic characteristics were compared between RARC and ORC using complex survey chi-square tests [10] . Propensity score methods [11] were used to compare RARC and ORC with respect to lymphadenectomy use, inpatient morbidity and mortality, transfusions, parenteral nutrition use, discharge disposition, lengths of stay, and costs. Propensity score methods permit control for observed confounding factors that may influence both group assignment (RARC or ORC) and outcomes using a single composite measure, and they attempt to balance patient characteristics between groups. We used a logistic regression model to calculate the propensity (probability) of undergoing RARC or ORC based on all covariates previously described and then weighted each subject's data based on the inverse propensity of being in one of the two treatment groups [12] . In the model, age and hospital cystectomy volume were included as continuous variables, whereas all other variables were categorical. In our propensity-adjusted analyses, there were eight primary outcomes. Six were categorical: lymphadenectomy use, death, inpatient complications, transfusions, parenteral nutrition use, and discharge disposition. Age and comorbidity were assessed as continuous variables. Secondary outcomes included inpatient complication subtypes. All analyses were performed with SAS v.9.2 (SAS Institute Inc., Cary, NC, USA), and all tests were considered statistically significant at p < 0.05.

3. Results

3.1. Characteristics of study sample

There were 224 RARCs and 1444 ORCs performed at 234 hospitals within the NIS, representing 1144 RARCs and 7168 ORCs after incorporating NIS survey weights. Thus, RARCs made up 13.3% of radical cystectomies in 2009. Demographics of the study population are shown in Table 2 .

Table 2 Demographic and hospital characteristics for open radical cystectomy compared with robot-assisted laparoscopic radical cystectomy

  Before propensity weighting After propensity weighting
Total Open Robotic p value Total Open Robotic p value
Subjects, no. 8312 7168 1144 0.999 8312 8209 103
Age, yr, median (IQR)   69 (68–70) 69 (68–70) 1.000   70 (69–71) 72 (69–75) 0.232
Gender, no. (%)
 Male 7086 6055 (84.5) 1031 (90.2) 0.048 6966 6872 (83.7) 94 (91.2) 0.053
 Female 1226 1114 (15.5) 112 (9.8)   1346 1337 (16.3) 9 (8.9)  
Race, no. (%)                
 White 5835 5135 (71.6) 700 (61.2) 0.497 1730 6519 (79.4) 63 (61.1) 0.053
 Nonwhite 801 680 (9.5) 122 (10.6)   6582 1690 (20.6) 40 (38.9)  
 Missing 1676 1354 (18.9) 323 (28.2)  
Comorbidity, no. (%)
 0–2 4756 4024 (56.1) 732 (64.0) 0.054 4310 4253 (51.8) 57 (55.3) 0.612
 ≥3 3556 3144 (43.9) 412 (36.0)   4002 3956 (48.2) 46 (44.7)  
Ileal conduit, no. (%) * 6343 5477 (76.4) 866 (75.7) 0.871 6610 6530 (79.6) 80 (77.9) 0.766
Primary payer, no. (%)
 Private 2483 2065 (28.8) 418 (36.5) 0.274 2154 2132 (26.0) 23 (22.2) 0.682
 Medicare 5118 4470 (62.4) 647 (56.6)   5459 5387 (65.6) 72 (70.1)  
 Medicaid/other 712 633 (8.8) 79 (6.9)   698 690 (8.4) 8 (7.8)  
Zip code income, no. (%)
 <$39 000 1681 1538 (21.9) 143 (12.9) 0.073 2259 2246 (27.4) 13 (12.4) 0.015
 $39 000–47 999 2236 1901 (27.1) 335 (30.3)   2061 2037 (24.8) 24 (23.4)  
 $48 000–62 999 2234 1897 (27.0) 338 (30.5)   2129 2102 (25.6) 27 (26.2)  
 ≥$63 000 1974 1684 (24.0) 291 (26.3)   1863 1824 (22.2) 39 (38.0)  
Hospital type, no. (%)
 Non-teaching 1848 1800 (26.1) 49 (4.3) <0.001 4098 4069 (49.6) 28 (27.6) 0.053
 Teaching 6182 5091 (73.9) 1091 (95.7)   4214 4140 (50.4) 75 (72.4)  
Hospital bed size, no. (%)
 Small 1165 708 (10.3) 457 (40.1) <0.001 2612 250 (3.1) 12 (11.3) 0.009
 Medium 1354 1178 (17.1) 175 (15.4)   1358 1348 (16.4) 10 (9.7)  
 Large 5511 5005 (72.6) 507 (44.5)   6692 6610 (80.5) 81 (79.1)  
Hospital region, no. (%)
 Northeast 1555 1220 (17.0) 335 (29.3) 0.129 1055 1038 (12.7) 17 (16.6) 0.800
 Midwest 3035 2676 (37.3) 359 (31.4)   2897 2856 (34.8) 41 (40.1)  
 South 1829 1734 (24.2) 95 (8.3)   2916 2886 (35.2) 30 (29.0)  
 West 1893 1539 (21.5) 354 (31.0)   1444 1429 (17.4) 15 (14.3)  
Hospital volume, median (IQR)   18 (16–20) 37 (36–38) <0.001   10 (9–11) 12 (5–19) 0.582

* Non–ileal conduit includes orthotopic neobladder or continent cutaneous reservoir identified with International Classification of Diseases, 9th Revision, code 57.87.

IQR = interquartile range.

Age, race, comorbidity, urinary diversion use, insurance payer type, income, and regional utilization were similar by surgical approach. The median age of both cohorts was 69 yr (p = 0.999), and 75.7% of RARCs and 76.4% of ORCs used ileal conduits (p = 0.871). Women were less likely to undergo RARC than ORC (9.8% and 15.5%, p = 0.048). Additionally, 95.7% of RARCs and 73.9% of ORCs were performed at teaching hospitals (p < 0.001). However, the robotic approach accounted for a larger proportion of radical cystectomy cases at small compared with large hospitals (p < 0.001). Median annual hospital radical cystectomy volume was higher among institutions performing RARCs than ORCs (37 compared with 18, p < 0.001).

3.2. Outcomes

Unadjusted and adjusted outcomes are presented in Table 3 . While secondary complication subtypes did not differ significantly in adjusted analyses, subjects undergoing RARC compared with ORC experienced fewer deaths (0% and 2.5%, p < 0.001) and fewer complications (49.1% compared with 63.8%, p = 0.035, excluding death). There was no difference in RARC compared with ORC blood transfusion use (32.0% and 37.9%, p = 0.448). While parenteral nutrition use was lower with RARC than with ORC (6.4% compared with 13.3%, p = 0.046), the likelihood of routine discharge (19.4% compared with 28.2%, p = 0.099) and median lengths of stay (8 d for both, p = 0.999) were similar. Moreover, concurrent pelvic lymph node dissection use did not differ significantly for RARC compared with ORC (76.8% and 67.0%, p = 0.248). Finally, RARC costs were greater than ORC costs (median $28 100 compared with $24 303, p = 0.023).

Table 3 Unadjusted and propensity-adjusted outcomes

  Unadjusted Adjusted
Primary outcomes Open n = 7168 Robotic n = 1144 p value Open Robotic p value
Categorical No. (%) %
Deaths 170 (2.4) 0 <0.001 2.5 0 <0.001
Inpatient complications 4318 (60.2) 541 (47.3) 0.004 63.8 49.1 0.035
Blood transfusion 2966 (41.4) 351 (30.7) 0.075 37.9 32.0 0.448
Parenteral nutrition 906 (12.6) 82 (7.2) 0.025 13.3 6.4 0.046
Routine discharge 1924 (27.5) 342 (29.9) 0.726 28.2 19.4 0.099
Lymph node dissection 4954 (69.1) 987 (86.3) <0.001 67.0 76.8 0.248
Continuous Median (IQR) Median (IQR)
Length of stay, d 8 (7.8–8.2) 7 (6.6–7.4) <0.001 8 (7.8–8.2) 8 (7.2–8.8) 0.999
Costs, $ 24 607

(23 741–25 474)
30 563

(28 911–32 215)
<0.001 24 303

(23 265–25 341)
28 100

(25 015–31 185)
0.023
Secondary outcomes
Categorical No. (%) %
Complication subtype
 Cardiac 645 (9.0) 55 (4.8) 0.013 10.3 5.6 0.110
 Respiratory 1282 (17.9) 144 (12.6) 0.067 18.4 15.2 0.421
 Genitourinary 798 (11.1) 91 (8.0) 0.243 11.3 6.6 0.112
 Wound 526 (7.3) 48 (4.2) 0.059 7.6 4.6 0.185
 Vascular 258 (3.6) 31 (2.7) 0.636 3.6 1.8 0.316
 Miscellaneous medical 3115 (43.5) 380 (33.3) 0.035 47.6 35.9 0.096
 Miscellaneous surgical 739 (10.3) 69 (6.0) 0.043 10.3 6.7 0.217

IQR = interquartile range.

4. Discussion

There is an absence of comparative population-based studies of RARC and ORC; most existing studies are single-surgeon series, whereby investigators may receive educational or research funding and/or serve on the speakers’ bureau for the device manufacturer. Moreover, estimates of robot-assisted surgery use are provided primarily by Intuitive Surgical (Sunnyvale, CA, USA), the manufacturer of the da Vinci robotic platform [13] . The rapid adoption of robot-assisted surgery for prostate cancer and other diseases has called into question whether, in the absence of clear evidence demonstrating significant superior clinical outcomes, the benefits of this technology justify the greater costs compared with competing open surgical approaches [13] .

Our study is the first population-based comparative study of RARC and ORC and has several important findings. First and most strikingly, there were no deaths associated with RARC compared with a 2.5% ORC inpatient mortality. Our ORC mortality is similar to the range of 0.3–3.9% from published series [14] . Population-based studies similarly demonstrated lower inpatient mortality for robotic than for open radical prostatectomy (0% and 0.2%) and nephrectomy (0% and 1.4%) [15] and [16]. However, our difference in RARC and ORC mortality is more pronounced, likely because of greater morbidity of radical cystectomy compared with radical prostatectomy and nephrectomy. While we found zero deaths with RARC, our findings must be interpreted in the context of the possibility that RARC perioperative mortality may increase with greater sampling. Additionally, the median annual hospital volume of 18 cases per year for ORC is significantly lower than 50 cases per year, which has been shown to be associated with lower mortality rates compared with lower surgical volumes [17] . Patients who die of BCa lose an average of 12 yr of income-producing life, valued at $200 000–500 000 per death [18] . Curtailing the life of BCa survivors as fatal sequelae of an elective surgical procedure exacerbates this significant loss.

Second, RARC was associated with fewer inpatient complications than ORC. While no one complication reached statistical significance, likely because of the low power for individual complication subtypes, the cumulative incidence of complications was lower for RARC. This finding suggests that no one complication subtype was driving this difference, which is consistent with prior studies of population-based studies that demonstrated fewer complications with the robotic than the open approach in inpatient settings [4], [15], [16], and [19]. Additionally, despite the World Health Organization and Société Internationale d’Urologie consensus that orthotopic diversion results in the lowest complication rates, >75% of all cystectomies used ileal conduit [20] . This has potential negative implications in the quality of cystectomy care and outcomes.

Third, there was no difference in the lengths of stay for RARC and ORC. While parenteral nutrition use was lower with RARC, consistent with comparative colorectal studies [21] and single-center series for laparoscopic radical cystectomy [22] and RARC [5] demonstrating earlier return of bowel function with minimally invasive approaches, this lower use did not appear to affect discharge disposition or hospital lengths of stay on a population-based level.

Fourth, RARC is more costly than ORC. Proponents of ORC argue that RARC incurs greater costs in the absence of definitive clinical benefit, which has been estimated to be approximately $1600 more per case in direct costs than ORC [13] . There are few studies on comparative cystectomy costs, and all arise from small single-center series. Thus, some contend that estimates reflect the experience of high-volume referral centers [23] . In our population-based study, we have found that the inpatient cost difference significantly exceeds this figure. While our hospital costs exclude surgeon fees and robotic system acquisition/maintenance costs, surgeon fees for robotic and open surgical procedures are similar. For instance, for radical prostatectomy, the most commonly performed robot-assisted procedure, physician reimbursement for robot-assisted compared with open radical prostatectomy differs by $107 [24] .

Fifth, women were less likely to undergo RARC than men. Female gender has previously been described as being associated with greater risk for cystectomy surgical morbidity [14] . Gender-based variation in surgical anatomy and need for anterior exenteration increase female cystectomy case complexity and may lead to female patient selection for ORC. However, there are potentially other confounders associated with gender that we were unable to control for, such as differences in body mass index or smoking status.

Sixth, RARCs were performed almost exclusively at teaching hospitals. Similarly, almost three-quarters of ORCs were also performed at teaching hospitals. Given the preponderance of RARCs at teaching hospitals, it may seem contradictory that smaller hospitals were more likely to perform RARCs than ORCs. However, smaller teaching hospitals were among the early adopters of robotic assistance for prostate cancer and heart surgery, and they are some of the highest-volume centers for robotic surgery [25] .

Finally, despite concerns that the robotic unit has limited maneuverability to perform an extended lymph node dissection [1] , subjects undergoing RARC were no less likely to undergo lymph node dissection than subjects undergoing ORC. Use of lymph node dissection during radical cystectomy is associated with better disease-specific survival, and performing an extended lymph node dissection during radical cystectomy has been suggested as a quality indicator [26] . RARCs were more commonly performed at teaching hospitals, where there may be greater surgeon adherence to oncologic practice guidelines compared with non-academic practice settings. While it is concerning that 33.0% of ORC patients and 23.2% of RARC patients did not undergo lymph node dissection, this finding is consistent with population-based studies of the US Surveillance Epidemiology and End Results tumor registries, where lymph node dissection was not performed in 21% of radical cystectomies [27] . Although we are unable to evaluate the yield and extent of lymph node dissections, others have shown that RARC lymph node yields are comparable to those of ORC [4] and [27].

Our study must be interpreted within the context of the study design. First, administrative data are designed for billing purposes and may lack detailed clinical information, such as continent diversion type in our study. While these data have been shown to have high sensitivity in capturing surgical complications [28] , we were unable to assess the severity or grade of these complications. Second, NIS characterizes only inpatient outcomes, and we were unable to assess readmissions, late complications, or earlier return to activities of daily living/work. Third, because of the absence of tumor characteristics and detailed clinical history, we were unable to assess body mass index, whether chemotherapy or irradiation was given prior to radical cystectomy, extent of lymph node dissection and yield, or differences in oncologic outcomes. However, the largest single-center comparative study found fewer RARC complications in the setting of similar pathologic stage compared with ORC [4] . Additionally, organ-confined versus non–organ-confined disease was not an independent predictor of complications, whereas surgical approach was predictive on multivariable analyses. Large single-center ORC series have not shown associations between tumor stage with early complications [29] , and a population-based study of 1126 ORCs found that pathologic stage did not affect 90-d reoperation or mortality [30] . Finally, we were unable to assess the effect of surgeon volume independent of hospital volume.

5. Conclusions

Compared with ORC, RARC is associated with less parenteral nutrition use and fewer inpatient complications and deaths. However, there was no difference in length of stay, and the robotic approach was significantly more costly.


Author contributions: Jim C. Hu had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Study concept and design: Yu, Hu.

Acquisition of data: Yu, Hevelone, Hu.

Analysis and interpretation of data: Yu, Hevelone, Lipsitz, Kowalczyk, Nguyen, Choueiri, Kibel, Hu.

Drafting of the manuscript: Yu, Hevelone, Lipsitz, Kowalczyk, Nguyen, Choueiri, Kibel, Hu.

Critical revision of the manuscript for important intellectual content: Yu, Hevelone, Lipsitz, Kowalczyk, Nguyen, Choueiri, Kibel, Hu.

Statistical analysis: Hevelone, Lipsitz.

Obtaining funding: Yu, Hu.

Administrative, technical, or material support: Hu.

Supervision: Hu.

Other (specify): None.

Financial disclosures: Jim C. Hu certifies that all conflicts of interest, including specific financial interests and relationships and affiliations relevant to the subject matter or materials discussed in the manuscript (eg, employment/affiliation, grants or funding, consultancies, honoraria, stock ownership or options, expert testimony, royalties, or patents filed, received, or pending), are the following: Dr. Yu receives salary support from the American Urological Association Foundation Research Scholars Award and the Robert and Kathy Salipante Minimally-Invasive Urologic Research Fellowship, and Dr. Hu receives salary support from the US Department of Defense Physician Training Award W81XWH-08-1-0283.

Funding/Support and role of the sponsor: None.

Acknowledgment statement: The authors acknowledge the efforts of the Healthcare Cost and Utilization Project in the creation of the NIS database, and the American Urological Association Research Scholars Program for supporting this work.

References

  • [1] B.J. Challacombe, B.H. Bochner, P. Dasgupta, et al. The role of laparoscopic and robotic cystectomy in the management of muscle-invasive bladder cancer with special emphasis on cancer control and complications. Eur Urol. 2011;60:767-775 Abstract, Full-text, PDF, Crossref.
  • [2] J.W. Davis, E.P. Castle, R.S. Pruthi, D.K. Ornstein, K.A. Guru. Robot-assisted radical cystectomy: an expert panel review of the current status and future direction. Urol Oncol. 2010;28:480-486 Crossref.
  • [3] J.A. Smith Jr., S.D. Herrell. Robotic-assisted laparoscopic prostatectomy: do minimally invasive approaches offer significant advantages?. J Clin Oncol. 2005;23:8170-8175 Crossref.
  • [4] C.K. Ng, E.C. Kauffman, M.M. Lee, et al. A comparison of postoperative complications in open versus robotic cystectomy. Eur Urol. 2010;57:274-282 Abstract, Full-text, PDF, Crossref.
  • [5] J. Nix, A. Smith, R. Kurpad, M.E. Nielsen, E.M. Wallen, R.S. Pruthi. Prospective randomized controlled trial of robotic versus open radical cystectomy for bladder cancer: perioperative and pathologic results. Eur Urol. 2010;57:196-201 Abstract, Full-text, PDF, Crossref.
  • [6] Agency for Healthcare Research and Quality. Overview of the Nationwide Inpatient Sample. Healthcare Cost and Utilization Project Web site. http://www.hcup-us.ahrq.gov/nisoverview.jsp . Updated November 2011.
  • [7] Agency for Healthcare Research and Quality. Comorbidity software, v.3.7. Healthcare Cost and Utilization Project Web site. http://www.hcup-us.ahrq.gov/toolssoftware/comorbidity/comorbidity.jsp . Updated October 2011.
  • [8] C.B. Begg, E.R. Riedel, P.B. Bach, et al. Variations in morbidity after radical prostatectomy. N Engl J Med. 2002;346:1138-1144 Crossref.
  • [9] Agency for Healthcare Research and Quality. Cost-to-charge ratio files. Healthcare Cost and Utilization Project Web site. http://www.hcup-us.ahrq.gov/db/state/costtocharge.jsp . Updated August 2011.
  • [10] J. Rao, A. Scott. On simple adjustments to chi-square tests with sample survey data. Ann Stat. 1987;15:385-397
  • [11] D.B. Rubin. Estimating causal effects from large data sets using propensity scores. Ann Intern Med. 1997;127:757-763 Crossref.
  • [12] J.M. Robins, M.A. Hernan, B. Brumback. Marginal structural models and causal inference in epidemiology. Epidemiology. 2000;11:550-560 Crossref.
  • [13] G.I. Barbash, S.A. Glied. New technology and health care costs—the case of robot-assisted surgery. N Engl J Med. 2010;363:701-704 Crossref.
  • [14] N. Lawrentschuk, R. Colombo, O.W. Hakenberg, et al. Prevention and management of complications following radical cystectomy for bladder cancer. Eur Urol. 2010;57:983-1001 Abstract, Full-text, PDF, Crossref.
  • [15] H. Yu, N. Hevelone, S. Lipsitz, K. Kowalczyk, J. Hu. Use, costs and comparative effectiveness of robotic assisted, laparoscopic and open urological surgery. J Urol. 2012;187:1392-1399 Crossref.
  • [16] Q.D. Trinh, J. Sammon, M. Sun, et al. Perioperative outcomes of robot-assisted radical prostatectomy compared with open radical prostatectomy: results from the Nationwide Inpatient Sample. Eur Urol. 2012;61:679-685 Abstract, Full-text, PDF, Crossref.
  • [17] C.E. Barbieri, B. Lee, M.S. Cookson, et al. Association of procedure volume with radical cystectomy outcomes in a nationwide database. J Urol. 2007;178:1418-1421 discussion 1421–2
  • [18] M.F. Botteman, C.L. Pashos, A. Redaelli, B. Laskin, R. Hauser. The health economics of bladder cancer: a comprehensive review of the published literature. Pharmacoeconomics. 2003;21:1315-1330
  • [19] J.C. Hu, X. Gu, S.R. Lipsitz, et al. Comparative effectiveness of minimally invasive vs open radical prostatectomy. JAMA. 2009;302:1557-1564 Crossref.
  • [20] R.E. Hautmann, H. Abol-Enein, K. Hafez, et al. Urinary diversion. Urology. 2007;69:17-49 Crossref.
  • [21] S.T. Orcutt, C.L. Marshall, C.N. Robinson, et al. Minimally invasive surgery in colon cancer patients leads to improved short-term outcomes and excellent oncologic results. Am J Surg. 2011;202:528-531 Crossref.
  • [22] J. Guillotreau, X. Game, M. Mouzin, et al. Radical cystectomy for bladder cancer: morbidity of laparoscopic versus open surgery. J Urol. 2009;181:554-559 discussion 559 Crossref.
  • [23] R. Lee, B. Chughtai, M. Herman, S.F. Shariat, D.S. Scherr. Cost-analysis comparison of robot-assisted laparoscopic radical cystectomy (RC) vs open RC. BJU Int. 2011;108:976-983 Crossref.
  • [24] CPT code/relative value search. American Medical Association Web site. https://ocm.ama-assn.org/OCM/CPTRelativeValueSearch.do .
  • [25] Cropper CM. The robot is in—and ready to operate. Businessweek. March 14, 2005. http://www.businessweek.com/magazine/content/05_11/b3924119_mz070.htm .
  • [26] H.W. Herr, J.R. Faulkner, Grossman, et al. Surgical factors influence bladder cancer outcomes: a cooperative group report. J Clin Oncol. 2004;22:2781-2789 Crossref.
  • [27] N.J. Hellenthal, A. Hussain, P.E. Andrews, et al. Lymphadenectomy at the time of robot-assisted radical cystectomy: results from the International Robotic Cystectomy Consortium. BJU Int. 2011;107:642-646 Crossref.
  • [28] A.G. Lawthers, E.P. McCarthy, R.B. Davis, L.E. Peterson, R.H. Palmer, L.I. Iezzoni. Identification of in-hospital complications from claims data: is it valid?. Med Care. 2000;38:785-795 Crossref.
  • [29] M.S. Cookson, S.S. Chang, N. Wells, D.J. Parekh, J.A. Smith Jr. Complications of radical cystectomy for nonmuscle invasive disease: comparison with muscle invasive disease. J Urol. 2003;169:101-104
  • [30] F. Liedberg, E. Holmberg, S. Holmang, et al. Long-term follow-up after radical cystectomy with emphasis on complications and reoperations: a Swedish population-based survey. Scand J Urol Nephrol. 2012;46:14-18 Crossref.

Footnotes

a Division of Urology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA

b Center for Surgery and Public Health, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA

c Department of Urology, Georgetown University Hospital, Washington, DC, USA

d Department of Radiation Oncology, Lank Center for Genitourinary Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA

e Department of Medicine, Lank Center for Genitourinary Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA

f Institute of Urologic Oncology, Department of Urology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA

lowast Corresponding author. UCLA Department of Urology, 924 Westwood Blvd., Suite 1000, Los Angeles, CA 90024, USA. Tel. +1 310 206 2355; Fax: +1 310 794 6789.