Introduction:

In the United States (U.S.), bladder cancer is among the most costly cancers, with total national expenditures estimated at $3.98 billion in 2010 and projected to reach $5.38 billion by 2020. Approximately 80,470 individuals will be diagnosed with bladder cancer in 2019, among whom an estimated 10,000 will undergo a radical cystectomy and urinary diversion (UD) surgery.  The majority of these patients will receive an ileal conduit, while about 20% will have a neobladder constructed. Though prior studies have estimated medical care costs of bladder cancer patients following radical cystectomy, there is limited information on costs by UD type, specifically. Efforts to understand the potential benefits and costs associated with different UD types are important to assess outcomes between treatment strategies among bladder cancer patients, and to inform efforts to reduce costs and burdens of care after cystectomy. To address the knowledge gap in this area, we estimated total health care costs in the year following radical cystectomy among bladder cancer patients treated with cystectomy and UD, comparing costs between ileal conduit and neobladder patients.  

Methods:

The Bladder Cancer Quality of Life (BCQOL) Study included patients diagnosed with bladder cancer who underwent radical cystectomy and received an ileal conduit (IC, n=821) or neobladder (NB, n=181) urinary diversion at one of three integrated health systems. Data for this study were obtained from clinical and administrative databases and included demographic, health plan coverage, clinical and utilization. For each patient, we summarized monthly counts of inpatient days, same day surgeries, hospital ambulatory encounters, emergency room visits, and outpatient clinic visits divided into the following groups: primary care, oncology, nephrology, urology, cardiology and other specialty visits. Cost coefficients were then applied to the utilization counts and summed to obtain total medical care costs, from the health system perspective. Monthly medical care costs per patient were estimated from the month of radical cystectomy through the 11 months following cystectomy, separated into quarters: Quarter 1=month of radical cystectomy (month 0) through month 2 following cystectomy; Quarter 2=months 3-5 following cystectomy; Quarter 3=months 6-8 following cystectomy; Quarter 4=months 9-11 following cystectomy. Multivariable generalized linear models with a gamma distribution and log link were used to estimate mean monthly total medical care costs per quarter (2012 USD$) and 95% confidence intervals [95% CI]. Cost estimates by UD type, tumor stage at cystectomy, presence of any complications, surgical approach, and death in quarter were obtained based on the marginal means from the multivariable model.

Results:

Compared to patients who received an IC, those with an NB were more likely to be younger, female, have a lower comorbidity burden, have lower tumor stage at cystectomy and have underwent robotic surgery. In multivariable analysis, mean monthly cost totals per quarter were not significantly different between IC and NB patients in the 12 months following cystectomy. Overall, mean monthly total costs were highest in Quarter 1 (IC patients_mean=$33,751 and NB patients_mean=$37,061) and decreased each quarter thereafter: Quarter 2 (IC patients_mean=$4,823 and NB patients_mean=$3,621); Quarter 3 (IC patients=$3,630 and NB patients $3,018) and Quarter 4 (IC patients_mean=$2,557 and NB patients $2,462). Patients with any complications had statistically significantly higher mean monthly total costs per quarter than those without complications (all p<0.001): Quarter 1 (any complications=$37,646 vs. no complications=$25,315; Quarter 2 (any complications=$5,562 vs. no complications=$1,705); Quarter 3 (any complications=$4,262 vs. no complications=$963); and Quarter 4 (any complications=$2,851 vs. no complications=$931). Compared to patients who underwent robotic surgery, those patients who did not undergo robotic surgery had similar mean monthly total costs in Quarter 1 (robotic_mean=$33,108 vs. non-robotic_mean=$34,479) and Quarter 2 (robotic_mean=$5,298 vs. non-robotic_mean=$4,486; although, mean monthly total costs for patients with robotic surgery were statistically significantly lower in Quarter 3 ($2,025) than for those without robotic surgery ($3,751, p<0.05) and remained lower (not statistically significant) in Quarter 4 (robotic_mean=$1,895 vs. non-robotic_mean=$2,636).  

Conclusion:

In this large retrospective, observational study assessing medical care costs of bladder cancer patients by type of continent urinary diversion, we found that costs in the year following radical cystectomy were similar between patients who received an ileal conduit and those who received a neobladder. Our study is among the first to estimate the economic burden to the health care system of bladder cancer patients who receive an ileal conduit or a neobladder, by UD type, addressing an important knowledge gap about cost patterns between different treatment approaches. We found that costs in the year following radical cystectomy were similar between patients who received an ileal conduit and those who received a neobladder, and that higher than average costs were driven, in part, by the occurrence of post-cystectomy complications. These findings highlight potential costs drivers that may serve as valuable targets for future cost containment strategies. Future research should explore patient reported outcomes and costs, by UD type, to further provide valuable information that may be used in treatment decision-making and cost conversations.

Funding: R01CA164128