Sample Characteristics & Treatment Patterns
There were a total of 755,375 encounters identified where a patient had diagnosis of prostate cancer. Encounters were then excluded for having diagnoses of cancers other than prostate cancer (4%), encounters associated with a patient being less than 40 years of age (0.1%) and encounters associated with a patient being female (0.04%). These exclusions resulted in 723,783 encounters eligible for analysis, which represents 265,112 unique patients. Out of these eligible encounters, 71% did not have any evidence of PCa-related treatment, leaving a total of 211,440 encounters with evidence of treatment, which represented 118,300 unique patients. In the sample of 211,440 encounters, 88,151 were hospital stays and 123,289 were hospital-based outpatient visits. Overall, most encounters took place in the South (43.5%) followed by the Midwest (22.4%) (Table 1). Additionally, most encounters occurred at urban (85.2%), nonteaching (60.8%) hospitals where the average bed size was 432 (Table 1).
The mean age of the sample of encounters was 69 years, with 65% being Caucasian (Table 1). The mean age is consistent with the most common payer type, Medicare (61.7%); however, 31.5% of encounters were associated with commercial/private payer reimbursement (Table 1). For patients with an inpatient hospitalization, the mean length of stay was 4.40 days (SD: 7.89). The most common treatment provided during inpatient stays was hormonal therapy (69%), which included primary (30%) and secondary hormonal therapy (39%). Primary hormonal therapies included, but were not limited to, 5-α reductase inhibitors (e.g., finasteride), antiandrogens (e.g., bicalutamide) and gonadotropin-releasing hormones. Secondary hormonal therapy included steroid therapies such as prednisone and dexamethasone. In contrast, the most common treatment in the hospital outpatient setting was radiation (76%). The most common types of radiation procedures were high dose rate brachytherapy, interstitial brachytherapy and external beam radiation therapy. Surgery was associated with 57% of inpatient hospitalizations, making it the second-most common treatment associated with inpatient stays. The types of surgeries included, but were not limited to, transurethral resection of the prostate, radical prostatectomy, surgical prostatectomy and prostate ablation. Very few encounters were associated with the receipt of nuclear medicine-related PCa therapy (e.g., iodine-125, palladium and samarium-152 among others) in the inpatient and hospital outpatient settings: 0.5 and 8%, respectively.
The majority of hospitalizations were associated with a primary diagnosis or admitting code for PCa (58.6%), while 78,489 hospitalizations (37.1%) were associated with a secondary diagnosis code for PCa only and the remaining 4.3% of the sample had both a primary/admitting and secondary diagnosis code for PCa. A summary of the primary diagnosis codes for men with a secondary diagnosis code of PCa is described in Table 2. For men with a secondary diagnosis code for PCa only, the most common primary diagnosis codes were diseases of the circulatory system, diseases of the respiratory system and diseases of the genitourinary system for inpatient hospitalizations (Table 2). With respect to hospital-based outpatient visits, the most common primary diagnosis code for men with a secondary diagnosis code of PCa was "Supplementary classification of factors influencing health status and contact with health services," which is relatively more common in an outpatient setting.
Overall, 160,026 encounters were associated with a single treatment for PCa, which accounted for the majority of both inpatient stays (69.6%) and outpatient visits (80.0%) (Table 3 & Table 4). Nearly all encounters associated with a single treatment during an inpatient stay were also associated with surgery (53.0%) or some form of hormone therapy (44.8%). In the outpatient setting, the majority of encounters with a single treatment were associated with radiation (80.8%). Approximately one in three encounters in the inpatient setting were associated with multimodal therapy, with 27.3% of inpatient stays associated with two treatments and 3.0% of inpatient stays associated with three or more treatments (Table 3). For encounters associated with two treatments during an inpatient stay, the most common treatment combination was surgery combined with secondary hormonal therapy (55.5%), followed by a combination of primary and secondary hormonal therapies (21.1%). For encounters associated with three or more treatments during an inpatient stay, the majority received a combination of hormonal therapy with surgery (34.0%), radiation (24.1%) or chemotherapy (21.4%). Twenty percent of encounters were associated with multimodal therapy during a hospital-based outpatient visit, with 15.5% and 4.5% of outpatient visits associated with two and three or more treatments, respectively (Table 4). For encounters associated with two treatments during an outpatient visit, the most common treatment combination was radiation combined with nuclear medicine (27.6%). For encounters associated with three or more treatments during an outpatient visit, the majority received combination hormonal therapy with radiation (32.3%).
The total average cost per hospitalization for inpatient stays was US$12,286 (Table 5). With an overall average length of stay at 4.4 days, room and board charges contributed 31% of the overall cost for PCa hospitalizations. Surgery was the second-largest cost item overall and the largest treatment-related cost item, representing 26% of inpatient hospitalization costs. Pharmaceuticals accounted for 8% of total inpatient costs. Overall, PCa-related treatment represented about 30% of all inpatients costs:prostate surgery = US$1996 per encounter; radiation = US$11 per encounter; chemotherapy = US$23 per encounter; hormone therapy = US$44 per encounter; secondary hormonal therapy = US$13 per encounter; and nuclear medicine = US$99 per encounter.
The total average cost per hospital-based outpatient visit was US$4364 (Table 5). PCa-related treatment costs (US$3134) represented 71.8% of all hospital-based outpatient costs, of which radiation and nuclear medicine costs (US$2661) were the primary drivers of total outpatient costs and represented 62.3% of total hospital-based outpatient costs. Surgery and pharmacy costs were also key components of hospital-based outpatient costs.
Future Oncol. 2015;11(3):439-447. © 2015 Future Medicine Ltd.