Healthcare Resource Utilization and Costs Associated with AL Amyloidosis: A Retrospective Matched Cohort Study

Introduction: AL (light-chain) amyloidosis is a chronic, incurable disease caused by the accumulation of misfolded proteins that disrupt cellular activities and impair organ functioning. The annual incidence is 10/million in Western countries and ~8.4/million in Taiwan. The burden of disease is substantial, and cardiac, renal, and liver involvement at diagnosis is common, with adverse effects on survival. The burden of AL amyloidosis on healthcare systems in Asia is not known.

Methods: We conducted a population-based study using the Taiwan National Healthcare Insurance Research database (NHIRD) to examine the healthcare resource utilisation (HRU) and costs associated with AL amyloidosis in Taiwan. All patients with confirmed newly diagnosed AL amyloidosis (ICD-10 E85.4, E85.8, E85.9) from 01-Jan-2016 until 31-Dec-2018 were enrolled. Patients without AL amyloidosis (comparators) were randomly selected from the NHIRD database and matched to cases in a 10:1 ratio by age, sex, and calendar year. Costs attributable to AL amyloidosis were obtained by subtracting the all-cause HRU costs incurred by comparators from cases. Patients were followed up until dis-enrolment, death, or study end (31 December 2019), whichever occurred first. Crude mean annual all-cause HRU for 3 years were reported for cases and comparators. Weighted Kaplan-Meier sample average (KMSA) annual costs were calculated to account for loss of follow-up due to death/disenrollment.

Results: Data from 645 patients with newly diagnosed AL amyloidosis were matched to 6450 comparators. The median age of all patients was 60.78 years and 59.07% were male. Common co-morbidities were cardiac-related in 27.29% of cases versus 12.11% in comparators, malignancy in 23.41% versus 4.43%, and renal-related in 21.71% versus 3.80%, respectively.

Three months after the index date, 8.4% of cases died compared with 0.45% of comparators. This increased to 12.1%/0.9% by 6 months and 18.8%/3.7% by 36 months after the index date.

Crude mean annual all-cause HRU in cases exceeded that of comparators. Compared to comparators, cases had 103% more outpatient visits, 177% more emergency room visits, were hospitalised 4-times more frequently, and spent 5.5-times more days in hospital. The difference between cases and comparators decreased in year 2 and year 3, but HRU remained substantially higher in cases than comparators.

Cumulative mean annual all-cause costs were significantly higher in cases than comparators over the entire 3-year follow-up period (p<0.0001 for all comparisons) (Table 1). The mean total cost attributable to AL amyloidosis was NT$ 449,643 (SD 36,419) (USD 14,271, SD 1,156) after 3 years, made up of NT$ 259,560 (SD 20,379) (USD 8238, SD 646) for outpatient visits, NT$ 148,207 (SD 20,704) (USD 4704, SD 657) for inpatient episodes, and NT$ 13,242 (SD 4,575) (USD 420, SD 145) for emergency room visits (Table 1). Outpatient care contributed about 62%-64% and inpatient care 34%-36% to the 1-year, 2-year, and 3-year cumulated total costs. Costs incurred during the first year after diagnosis accounted for 55% of the 3-year cumulative cost. The total cost of all-cause healthcare after 3 years was 4-fold higher in cases compared to comparators.

Similarly, cumulative mean annual medication and non-medication costs were higher in cases than comparators over the entire 3-year follow-up period (p<0.0001 for all comparisons) (Table 2). Medication costs accounted for 45%-48% of the 1-year, 2-year, and 3-year cumulated total costs. The mean total cost of medications attributable to AL amyloidosis was NT$ 212,606 (SD 27,497) (USD 6,748, SD 872) after 3 years, and the mean non-medication cost was NT$ 257,232 (SD 25,720) (USD 8,164, SD 816). 58% of the AL amyloidosis-attributable medication costs and 52% of the attributable non-medication costs over the 3-year follow-up period were incurred in the first year after diagnosis.

Conclusion: This analysis used data from the NHIRD that provides health insurance for the whole population of Taiwan, allowing complete and longitudinal data collection across all treatment settings. Patients with newly diagnosed AL amyloidosis had high levels of co-morbidity and high early mortality. Over a 3-year period after diagnosis, mortality was 5-times higher, and the all-cause total cost was 4-times higher in cases than in comparators.

Huang:Johnson & Johnson: Current Employment. Goh:Johnson & Johnson: Ended employment in the past 24 months. Qiu:Johnson & Johnson: Current Employment, Current equity holder in publicly-traded company. Rothwell:Johnson & Johnson: Current Employment, Current equity holder in publicly-traded company. Wu:Johnson & Johnson: Current Employment. Chandwani:Johnson & Johnson: Current Employment, Current equity holder in publicly-traded company. Liu:Johnson & Johnson: Current Employment, Current equity holder in publicly-traded company.