Economic evaluation of digitally supported therapy for people with psychosis who hear distressing voices: the AVATAR2 trial

Abstract

BACKGROUND: AVATAR therapy, a digitally supported intervention, utilises avatars to promote recovery in people who experience distressing auditory hallucinations. This approach was recently evaluated in a multicentre randomised controlled trial comparing brief (AV-BRF) and extended (AV-EXT) forms of therapy with treatment as usual (TAU). There was evidence for the effectiveness of therapy, particularly for AV-EXT. However, value for money needs to be assessed. AIMS: To compare separately the cost utility of the brief and extended forms of AVATAR therapy with TAU. METHOD: In a three-arm randomised controlled trial the use of health services was measured, and costs (2021/2022; pounds sterling) calculated from a health and social care perspective over a 28-week follow-up period. Quality-adjusted life years (QALYs; derived from the 5-level version of the EuroQol 5-Dimension questionnaire) were combined with costs. RESULTS: AV-BRF resulted in extra costs of £319 (95% CI, -£1558 to £2496), and AV-EXT in lower costs of £1965 (95% CI, -£1912 to £1519), compared with TAU. Over the follow-up, AV-BRF resulted in 0.0159 (95% CI, -0.0103 to 0.0422) and AV-EXT in 0.0173 (95% CI, -0.0049 to 0.0395) more QALYs than TAU. The cost per QALY for AV-BRF compared with TAU was £20 016, while AV-EXT dominated TAU (lower costs and more QALYs). CONCLUSIONS: Neither version of AVATAR had a substantial impact on QALYs. However, AV-EXT did result in reduced care costs - albeit not statistically significant - and was potentially cost-effective compared with TAU. AV-BRF had an incremental cost-effectiveness ratio that indicated lower potential cost-effectiveness. These findings are uncertain, but could still inform decision-making regarding interventions in this field.