Economic evaluation of a complex intervention to improve the mental health of maltreated children in foster care (BeST? Services trial).

Background: Children in foster care who have experienced abuse and neglect are at risk of poor long-term health and societal outcomes. Evidence on the costs, benefits and cost-effectiveness of early interventions aimed at improving the mental health of abused and neglected children is limited.

Methods: This study reports the within-trial economic evaluation alongside BEST?, a randomized controlled trial comparing the New Orleans Intervention Model (NIM) with services as usual (SAU), targeting children aged 0-60 months entering UK foster care.In line with guidance for conducting economic evaluations of complex and social care interventions, a cost-utility analysis (CUA) estimated incremental cost of NIM per quality-adjusted life year (QALY); a cost-effectiveness analysis estimated incremental cost per unit improvement in child mental health; and a cost-consequence analysis combined costs with broad-ranging outcomes.

Results: NIM is significantly more costly than SAU (NIM: £10 002; SAU: £4336), with wide cost variations according to context. There are no significant differences between NIM and SAU in QALYs or child mental health.

Conclusions: Within the current UK care systems, NIM is not a cost-effective alternative to SAU. However, these results need to be interpreted with caution and within the prevailing service provision context.