Economic evaluation of day hospital versus intensive outpatient mentalization-based treatment alongside a randomized controlled trial with 36-month follow-up.

Mentalization-based treatment (MBT) has demonstrated robust effectiveness in the treatment of borderline personality disorder (BPD) in both day-hospital (MBT-DH) and intensive outpatient MBT (MBT-IOP) programs. Given the large differences in intensity and associated treatment costs, there is a need for studies comparing their cost-effectiveness. A health economic evaluation of MBT-DH versus MBT-IOP was performed alongside a multicenter randomized controlled trial with a 36-month follow-up. In three mental health-care institutions in the Netherlands, 114 patients were randomly allocated to MBT-DH ( = 70) or MBT-IOP ( = 44) and assessed every 6 months. Societal costs were compared with quality-adjusted life years (QALYs) gained and the number of months in remission over 36 months. The QALY gains over 36 months were 1.96 ( = .58) for MBT-DH and 1.83 ( = .56) for MBT-IOP; the respective number of months in remission were 16.0 ( = 11.5) and 11.1 ( = 10.7). Societal costs were €106,038 for MBT-DH and €91,368 for MBT-IOP. The incremental cost for one additional QALY with MBT-DH compared with MBT-IOP was €107,000. The incremental cost for 1 month in remission was almost €3000. Assuming a willingness-to-pay threshold of €50,000 for a QALY, there was a 33% likelihood that MBT-DH is more cost-effective than MBT-IOP in terms of costs per QALY. Although MBT-DH leads to slightly more QALYs and remission months, it is probably not cost-effective when compared with MBT-IOP for BPD patients, as the small additional health benefits in MBT-DH did not outweigh the substantially higher societal costs. (PsycInfo Database Record (c) 2023 APA, all rights reserved).