Background
To estimate insurance payments and patient out-of-pocket (OOP) expenses associated with discarded weight-based intravenous anti-neoplastic drugs for privately insured US adult cancer patients.
Methods
We identified patients who received weight-based anti-neoplastic drugs from 2017 MarketScan Health Risk Assessment (HRA) linked to claims data. Using weight information in the HRA, we derived the recommended dose and calculated the percentage of drugs discarded. We applied beta regression to determine factors associated with the discarded percentages. To compare patients with and without high-deductible plans, we employed generalized linear model and two-part model to examine insurance payment and OOP expense, respectively. All statistical tests were 2-sided.
Results
Of 27,350 claims for 58 weight-based anti-neoplastic drugs from 1,970 patients, the median discarded percentage was 9.8% (mean = 12.8%, SD = 10.5%). Aside from drug and tumor type, statistically significantly higher discarded percentages were found for patients in the lowest weight group (5.5%, 95% confidence interval = 4.7% – 6.4%; P < .001, weight <150 vs. ≥200 lb). Private payers spent $5,090 per patient in 2017 on discarded weight-based anti-neoplastic drugs and patients’ mean OOP expense on discarded drugs was $63. 39.7% of patients had high-deductible plans. The adjusted mean OOP expense for discarded drugs was statistically significantly higher for those in high-deductible plans ($95 vs. $47, P < .001).
Conclusions
Private insurers incurred substantial financial burden from discarded weight-based anti-neoplastic drugs. Although OOP expenses of discarded drugs were modest for most privately insured cancer patients, approximately 5% spent over $400 on the discarded drugs. Policies designed to reduce drug waste from single-dose, weight-based anti-neoplastic drugs should evaluate their financial consequences for payers and patients.