Direct economic burden of high-risk and metastatic melanoma in the elderly: Evidence from the SEER-Medicare linked database

Abstract

While the clinical implications of advanced melanoma have been extensively documented, little is known about the direct medical costs associated with the disease, particularly for elderly patients who carry the highest disease incidence and morbidity. To document resource utilization and costs to the Medicare system for elderly patients with high-risk (stages IIB/C, IIIA/B, IIIC) or metastatic (stage IV) melanoma. Data were taken from the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database combining clinical information on incident cancer cases in the US between 1991 and 2002 with longitudinal (1991-2005) administrative Medicare claims. Subjects aged >/=65 years with at least one stage IIB or higher melanoma diagnosis were selected. An index date was identified corresponding to the first observed stage IIB or higher diagnosis. Subjects were then categorized into mutually exclusive index disease stages, based on the SEER-reported melanoma stage observed at the index date. All subsequent analyses were stratified according to the index disease stage. Subjects without a record of death were required to have at least 6 months of continuous Medicare Part A and Part B benefits coverage before and after their index date. Subjects who died <6 months after their index date were retained for analysis. Resource utilization and costs were evaluated for each patient from index date until death, benefits cessation or end of the database (31 December 2005). Cost data were inflated to 2007 $US and stratified by the care setting in which they were incurred: inpatient hospital, skilled nursing facility, emergency room, physician office, home healthcare, hospice and other ancillary. 6470 subjects met all inclusion criteria. Index stage distribution was: IIB/C (38%), IIIA/B (46%), IIIC (1%) and IV (15%). Median follow-up was 56, 39, 16 and 6 months, respectively. Patients with stage IV disease had 3.1 hospital days per month, compared with 0.5, 0.6 and 1.1 days for stage IIB/C, IIIA/B and IIIC patients, respectively. Adjusted inpatient costs for stage IV subjects were $US5565 per patient per month versus $US1031, $US1440 and $US2275 for stage IIB/C, IIIA/B and IIIC patients, respectively (p < 0.0001). Adjusted total costs were $US11 471 per month for stage IV subjects, compared with $US2338, $US3395 and $US6885 for stages IIB/C, IIIA/B and IIIC, respectively (p < 0.0001). The per-patient cost of advanced melanoma is high. Hospital services are the largest component of these costs. Monthly costs for subjects with stage IV melanoma were 67% higher than costs for subjects with stage IIIC disease and >3-fold higher than costs for patients with stages IIIA/B and IIB/C. However, when combining estimated monthly costs with median follow-up duration (a proxy for survival time), total costs incurred by Medicare appear to be highest for patients diagnosed at stage IIIA/B