Changes in spending and service use after a state autism insurance mandate

We evaluated a 2011 Kansas law mandating comprehensive coverage of autism spectrum disorder treatments in the State Employee Health Plan. Data were extracted from the Kansas All-Payer Claims Database from 2009 to 2013 for enrollees of State Employee Health Plan and private health plans.

The sample included children aged 0–18 years with >2 claims with an autism spectrum disorder diagnosis insured through State Employee Health Plan or a comparison group enrolled through private health plans. We estimated differences-in-differences regression models to compare trends among State Employee Health Plan to privately insured children. Average annual total spending on autism spectrum disorder services increased by US$912 (95% confidence interval: US$331–US$1492) and average annual out-of-pocket spending on autism spectrum disorder services increased by US$138 (95% confidence interval: US$53–US$223) among diagnosed children in the State Employee Health Plan relative to the comparison group following the mandate, representing 92% and 75% increases over baseline total and out-of-pocket autism spectrum disorder spending, respectively.