Cost-utility analysis of the Circle of Security-Parenting programme to reduce perinatal psychopathology in birthing parents in England

Objectives:The Circle of Security-Parenting (COS-P) group intervention has demonstrated efficacy in reducing maternal perinatal mental health difficulties (PMHD) symptoms in some contexts.The COSI study, a multisite, individually randomised, single-blind, parallel-arm controlled trial, was conducted in England to assess the clinical effectiveness of COS-P in reducing perinatal psychopathology, parenting and infant development, as well as its acceptability among the National Health Service (NHS) participants and staff.Main aim of this work is to estimate the cost-utility of COS-P plus Treatment as Usual (TAU) relative to TAU amongst mothers and birthing parents receiving NHS perinatal mental health services (PMHS) in England.Design: A within-trial economic evaluation was performed comparing COS-P plus TAU with TAU alone, using data from the COSI trial, which employed a 2:1 randomisation ratio.Analyses were conducted from both NHS and Personal Social Services (PSS), and societal perspectives.A 12-month time horizon was used, consistent with the final trial follow-up.Setting: Secondary care NHS perinatal health services across multiple centres in England.Participants: A total of 371 mothers and birthing parents with PMHD were randomised and had complete economic outcome data; 248 received COS-P plus TAU and 123 received TAU alone.Participants were eligible if they were receiving NHS PMHS; exclusion criteria were defined in the trial protocol.Interventions: Participants in the intervention arm received the COS-P group programme in addition to TAU.The control group received TAU alone. Primary and Secondary Outcome Measures:The primary economic outcome was qualityadjusted life years (QALYs) over 12 months, derived from EQ-5D-5L responses.Costs were estimated from NHS and Personal Social Services (PSS), and societal perspectives, including healthcare utilisation and productivity losses due to work absence.Results: Compared with TAU, COS-P was associated with higher costs from both NHS and PSS (180.58;95% CI: -1,075 to 1,436) and societal (72.94;95% CI: -1,473 to 1,619) perspectives.COS-P was marginally less effective in terms of QALYs (-0.01; 95% CI: -0.06 to 0.05).Probabilistic sensitivity analyses indicated substantial uncertainty around cost and effectiveness estimates.