Contemporary relationship between medical expenditures and quality of life among adults with epilepsy in the United States

Aims: Epilepsy exacts substantial adverse economic and quality of life (QoL) costs. Clarifying the quantitative and qualitative relationships between total and out-of-pocket (OOP) healthcare expenditures and QoL could shed insights into how they influence each other, and have done so over recent times. Methods: We used the Medical Expenditure Household Components 2003–2014 to identify a total of 2450 adults with epilepsy, representing a weighted population of 1,942,413. Quality of life was assessed using the Physical Component Summary (PCS) and the Mental Component Summary (MCS) derived from the Short-form 12 Version 2 (SF-12 V2), converted into quartiles of equal distribution, with higher quartiles indicating a better QoL. We computed unadjusted mean and adjusted (through a generalized linear model (GLM)) total and OOP healthcare expenditures by QoL categories among adults with epilepsy (reported as dollars in 2016). Results: The pooled estimates of total healthcare expenditures decreased as PCS and MCS quartiles of QoL increased [PCS: costs for quartile 1 = $21,792 (95% confidence interval (CI): $18,416–$25,168 vs. costs for quartile 4 = $6057 (95% CI: $4648–$7466) and MCS: costs for quartile 1 = $19,040 (95% CI: $15,544–$22,535) vs. quartile 4 = $12,939 (95% CI: $8450–$17,429)]. Similarly, the pooled estimates of OOP healthcare expenditures and QoL were inversely related [PCS: costs for quartile 1 = $1849 (95% CI: $1583–$2114) vs. costs for quartile 4 = $948 ($709–$1187) and MCS: costs for quartile 1 = 1812 (95% CI: $1483–2141) vs. quartile 4 = $1317 (95% CI: $982–$1652)]. The association between QoL and total and OOP healthcare expenditures was unchanged after adjusting for socioeconomic and healthcare system related confounders in the GLM. Overall, healthcare expenditures were stable across years independently of the QoL; only OOP expenditures decreased between 2003–2006 and 2011–2014 for quartile 1 of PCS and MCS. Conclusion: Quality of life and OOP health expenditures are independently and inversely related to each other among adults with epilepsy. Over the decade studied in the United States, there was a decrease in OOP health expenditures among those patients with epilepsy with the lowest QoL, possibly reflecting a rise in insurance coverage after the Affordable Care Act.