The Impact of State Chemotherapy Parity Laws on Use and Spending for Oral Chemotherapy
Objectives: To estimate the effect of oral chemotherapy parity laws on patient out-of-pocket and drug and non-drug health plan spending.
Methods: We used administrative health plan claims from 2008-2012 for three large nationwide insurers aggregated by the Health Care Cost Institute. We compared oral chemotherapy use, out-of-pocket spending for oral chemotherapy, and total and chemotherapy-related health plan spending for chemotherapy users pre- and post-parity in states with and without legislation among individuals in fully-insured vs. self-funded plans (which are exempt from state laws) using a difference-in-difference-in-differences approach.
Results: We studied 29,944 individuals, representing 172,239 chemotherapy-months. Oral chemotherapy use increased as a proportion of all chemotherapy use from 16.6% to 22.0% from 2008 to 2012. There were no differences in use by parity or plan funding type (fully-insured versus self-funded) (adjusted difference-in-difference-in-differences risk ratio:0.93, 95%CI:0.75-1.15;p=0.50). For patients in plans subject to parity, out-of-pocket spending decreased by $26.55 (p<0.001) at the median and $222.20 at the 90th percentile (p<0.001), but benefits for high spenders were inconsistent. There were no parity-associated increases in chemotherapy-related or total spending by health plans.
Conclusions: Chemotherapy parity laws are associated with reductions in out-of-pocket spending for many patients without corresponding increases in plan spending; however, savings were inconsistent, including among the highest spenders. Cancer parity laws alone may be insufficient to ensure patients are protected from high out-of-pocket costs. Nevertheless, federal efforts to extend parity may improve chemotherapy access for many patients not reached by state laws.