The Impact of State Chemotherapy Parity Laws on Use and Spending for Oral Chemotherapy

Background: Oral cancer medications are increasingly important in treating cancer but are costly for patients and insurers. By mid-2015, 39 states and Washington, D.C. had passed laws to ensure privately-insured patients pay no more for oral chemotherapy than intravenous chemotherapy. In June 2015 the Cancer Drug Coverage Parity Act of 2015 (H.R.2739, S.1566) was introduced in Congress to extend parity to all states and self-funded plans. The effect of these state laws on utilization and spending is unknown.

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 90^th 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.