The impact of HDHPs on service use and spending for substance use disorders.

Objectives: Although high-deductible health plans (HDHPs) reduce health care spending, higher deductibles may lead to forgone care. Our goal was to determine the effects of HDHPs on the use of and spending on substance use disorder (SUD) services.
Study Design: We used difference-in-differences models to compare service use and spending for treating SUD among enrollees who were newly offered an HDHP relative to enrollees offered only traditional plan options throughout the study period.
Methods: We used deidentified commercial claims data from OptumLabs (2007-2017) to identify a sample of 28,717,236 person-years (2.2% with a diagnosed SUD). The main independent measure was an indicator for being offered an HDHP. The main dependent measures were the probability of (and spending associated with) using SUD services and specific treatment types.
Results: Enrollees were 6.6% (P < .001) less likely to use SUD services after being offered an HDHP relative to the comparison group. Reductions were concentrated in inpatient, intermediate, and ambulatory care, as well as medication use. Being offered an HDHP was associated with a decrease of 21% (P < .001) on health plan spending and an increase of 14% (P < .01) on out-of-pocket spending.
Conclusions: Offering an HDHP was associated with a reduction in SUD service use and a shift in spending from the plan to the enrollee. In the context of the US drug epidemic, these study findings highlight a concern that the movement toward HDHPs may be exacerbating undertreatment of SUD.