Indirect costs associated with metastatic breast cancer

To compare the indirect costs of productivity loss between metastatic breast cancer (MBC) and early stage breast cancer (EBC) patients, as well as their respective family members.

The MarketScan Health and Productivity Management database (2005-2009) was used. Adult BC patients eligible for employee benefits of sick leave and/or short-term disability were identified with ICD-9 codes. Difference in sick leave and short-term disability days was calculated between MBC patients and their propensity score matched EBC cohort and general population (controls) during a 12-month follow-up period. Generalized linear models were used to examine the impact of MBC on indirect costs to patients and their families.

A total of 139 MBC, 432 EBC, and 820 controls were eligible for sick leave and 432 MBC, 1552 EBC, and 4682 controls were eligible for short-term disability (not mutually exclusive). After matching, no statistical difference was found in sick leave days and the associated costs between MBC and EBC cohorts. However, MBC patients had significantly higher short-term disability costs than EBC patients and controls (MBC: $6166 ± $9194 vs. EBC: $3690 ± $6673 vs.

$558 ± $2487, both p < 0.001). MBC patients had more sick leave cost than controls ($2383 ± $5539 vs. $1282 ± $2083, p < 0.05). Controlling for covariates, MBC patients incurred 47% more short-term disability costs vs EBC patients (p = 0.009). Older patients (p = 0.002), non-HMO payers (p < 0.05), or patients not receiving chemotherapy during follow-up (p < 0.001) were associated with lower short-term disability costs. MBC patients' families incurred 39.7% (p = 0.06) higher indirect costs compared to EBC patients' families after controlling for key covariates.

Productivity loss and associated costs in MBC patients are substantially higher than EBC patients or the general population. These findings underscore the economic burden of MBC from a US societal perspective. Various treatment regimens should be evaluated to identify opportunities to reduce the disease burden from the societal perspective.