Cost-effectiveness of a group psychological intervention for postnatal depression in British south Asian women : an economic evaluation from the ROSHNI-2 trial

Abstract

BACKGROUND: Minority ethnic groups often face ethnocultural barriers in accessing mental health treatments. The ROSHNI-2 trial compared culturally adapted cognitive behavioural therapy (Positive Health Programme [PHP]) with treatment as usual for postnatal depression in British south Asian women. We aimed to assess the cost-effectiveness of the PHP intervention. METHODS: The ROSHNI-2 trial was a multicentre, two-arm, assessor-blinded, randomised controlled trial; we conducted an economic evaluation over a 12-month period to assess the cost-effectiveness of PHP plus treatment as usual versus treatment as usual alone from the perspective of the English National Health Service and personal social services. In the trial, British south Asian women aged 16 years or older with a child aged up to 12 months, and meeting DSM-5 criteria for depression, were recruited from northwest England, Yorkshire, the East Midlands, and London. The PHP intervention involved 12 group sessions delivered by two trained bilingual facilitators, held once per week for 2 months and once per fortnight thereafter, each lasting 60-90 min. Questionnaires on depression symptoms, quality of life, and resource use were completed at baseline, 4 months (end of intervention), and 12 months after random assignment. Quality-adjusted life-years (QALYs) were used for the cost-utility analysis, and recovery from depression at 4 months (the primary clinical outcome), assessed using the Hamilton Rating Scale for Depression, informed the cost-effectiveness analysis. After the onset of the COVID-19 pandemic, the intervention was adapted for online delivery for the remaining participants. A stratified analysis compared the cost-effectiveness of online versus in-person delivery. The trial involved researchers with lived experience, and all methods, including health economic measures, were developed in consultation with service users, community members, and faith leaders. This is a preplanned analysis of the ROSHNI-2 trial, registered with ISRCTN (ISRCTN10697380). FINDINGS: From Feb 8, 2017, to March 29, 2020, 732 eligible women were enrolled: 368 participants were randomly assigned to the PHP arm and 364 to the treatment as usual arm. The base-case intention-to-treat analysis showed that PHP significantly increased costs (£712, 95% CI 311 to 1113) and QALYs (0·036, 95% CI 0·006 to 0·067), with an incremental cost-effectiveness ratio of £19 601 (7622 to 83 772). Based on the UK National Institute for Health and Care Excellence (NICE) maximum willingness-to-pay threshold of £30 000 per QALY, the likelihood of PHP being cost-effective was 77% from a health and social care perspective. Cost per remission from depression at the 4-month follow-up was £5509 (2916 to 17 860). In a stratified analysis of 34 participants attending online sessions during the pandemic, incremental QALY effects were 0·125 (0·048 to 0·203), resulting in costs of £202 (-3906 to 10 918) per additional QALY gained. INTERPRETATION: The average cost of PHP for postpartum women was below the lower end of the NICE threshold of £20 000-30 000 per QALY, excluding benefits to the child or potential gains such as reduced lost productivity from early remission. PHP, a culturally adapted group cognitive behavioural therapy-based intervention, might be a cost-effective intervention for postnatal depression in British south Asian women. Online PHP delivery showed promising clinical and cost-effective results for this group but requires a large-scale study. FUNDING: UK National Institute for Health and Care Research.