Choice of high-deductible health plans among enrollees with a substance use disorder

Introduction: High-deductible health plans (HDHPs) expose enrollees to increased out-of-pocket costs for their medical care, which can exacerbate the undertreatment of substance use disorders (SUDs). However, the factors that influence whether an enrollee with SUD chooses an HDHP are not well understood. In this study, we examine the factors associated with an individual with an SUD's decision to enroll in an HDHP. Methods: Using de-identified administrative commercial claims and enrollment data from OptumLabs (2007-2017), we identified individuals at employers offering at least one HDHP and one non-HDHP plan. We modeled whether an enrollee chose an HDHP using linear regression on plan and enrollee demographic char-acteristics. Key plan characteristics included whether a plan had a health savings account (HSA) or a health reimbursement arrangement (HRA). Key demographic variables included age, race/ethnicity, census block income range, census block highest educational attainment, and sex. We separately investigate new enrollment decisions (i.e., not previously enrolled in an HDHP) and re-enrollment decisions, as well as decisions among single enrollees and families of differing sizes. The study also adjusted models for additional plan characteristics, employer and year fixed effects, and census division. Robust standard errors were clustered at the employer level. Results: The sample comprised 30,832 plans and 318,334 enrollees. Among enrollees with new enrollment decisions, 24.6 % chose an HDHP; 93.8 % of HDHP enrollees chose to re-enroll in an HDHP. The study found the presence of a plan HRA to be associated with a higher probability of new and re-enrollment in an HDHP. We found that older enrollees with SUD were less likely to newly enroll in an HDHP, while enrollees who were nonWhite, living in lower-income census blocks, and living in lower educational attainment census blocks were more likely to newly enroll in an HDHP. Higher levels of health care utilization in the prior year were associated with a lower probability of newly enrolling in an HDHP but associated with a higher probability of re-enrolling. Conclusion: Given the emerging evidence that HDHPs may discourage SUD treatment, greater HDHP enrollment could exacerbate health disparities.