An evaluation of the healthcare costs associated with adverse events in patients with breast cancer

Objective: Despite the increasing prevalence and costs of breast cancer (BC), little is known about its adverse event (AE)-related costs in Asia. This study aimed to estimate the healthcare expenditures of AEs in patients with BC in Taiwan. Methods: This is a retrospective claims database analysis. The medical costs associated with BC AEs during the first-line treatment period were estimated by use of both a matching method and the generalized linear model (GLM). Results: A total of 50,010 patients diagnosed with breast cancer were identified. Using the case-control matching method, pneumonitis/pneumonia was the AE associated with the greatest total healthcare costs (NT$ 66,889), followed by arthralgia (NT$55,380). In the GLM, the estimated costs ranged from NT$ 1,045 for fatigue to NT$ 116,652 for left heart failure. Moreover, the estimated total healthcare incremental cost increased with the number of AEs (NT$18,157 for 1 AE, NT$33,827 for 2 AEs, NT$39,052 for 3 AEs, NT$53,348 for 4 AEs, and NT$54,215 for 5 AEs and above). Conclusions: The findings indicate that AEs among patients with BC were associated with a substantial economic burden, and healthcare expenditure rose significantly as the number of AEs increased.