Economic Evaluation of a Group Psychological Intervention for Postnatal Depression in British South Asian Mothers Alongside a Randomised Controlled Trial

Background: Ethnic minorities 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 (TAU) for postnatal depression in South Asian women. This study presents a health economic evaluation of the PHP intervention.

Methods: A total of 732 British South Asian women with depression were randomised (1:1), stratified by centre, into PHP plus TAU and TAU-only groups. The EuroQol 5-dimensional instrument was used for cost-utility analysis, while recovery from depression using the Hamilton Rating Scale for Depression was used for cost-effectiveness analysis.

Outcomes: The base-case intention-to-treat analysis showed PHP significantly increased costs (£912, 95% CI £420–£1405) and quality-adjusted life years (QALYs) (0.037, CI 0.006–0.068), with an incremental cost-effectiveness ratio (ICER) of £24,739 (CI £15,539–£39,692). Based on NICE's maximum willingness-to-pay (WTP) threshold of £30,000 per QALY, the likelihood of PHP being cost-effective was 63% from a health and social care perspective. Cost per remission from depression at the 4-month follow-up was £5,354 (CI £3,878–£7,189).
In a stratified analysis of 34 participants attending online sessions during the pandemic, incremental QALY effects were 0.134 (CI 0.073–0.194), resulting in costs of £397 (CI £-2,492–£3,339) per additional QALY gained.

Interpretation: The cost of PHP intervention for postpartum mothers falls within NICE's range of £20,000–£30,000 per QALY, excluding benefits to the child or potential gains like reduced lost productivity from early remission. With each episode of perinatal depression in the UK estimated to have a lifetime cost of £75,000 for the mother and child, and considering the cultural and linguistic needs of ethnic minorities, PHP may be a cost-effective intervention for postnatal depression in minority women. Online PHP delivery has shown promising clinical and cost-effective results for this group but requires further large-scale study.