Presentation (CTI)

OBJECTIVES: In 2025, the National Institute for Health and Care Excellence (NICE) published a position statement on the need for disease-specific reference case extensions to standardise health economic models for health technology assessment (HTA) in high-priority clinical areas, including mental health disorders. The first extension, published in May 2026, focused on obesity and relied on lessons from past technology appraisals (TAs). The suitability of available TAs in mental health disorders was assessed to inform the development of a disease-specific reference case extension.
METHODS: The NICE website was searched to identify existing TAs in mental health disorders. The targeted review focused on health economic models’ structure, inputs, assumptions, critiques by external assessment groups (EAGs), and committee-preferred assumptions.
RESULTS: Seven TAs were identified: three in depression, two in opioid dependence, one in schizophrenia, and one in bipolar disorder; published between 2007 and 2022. All included Markov models, and some included a decision tree followed by a Markov model, with the intent to capture the episodic nature of mental health disorders. The time horizon was between 1 and 20 years. Carer utility decrements were accepted as a base case assumption only in the most recent TA (from 2022). Although severity of disease was considered a relevant treatment effect modifier, evidence to inform subgroup analyses was limited. The cost-effectiveness results were associated with a high degree of uncertainty due to the lack of established definitions of response to treatment, unreliable health-related quality of life, and lack of long-term clinical evidence.
CONCLUSIONS: There is a paucity of available NICE TAs in mental health disorders, resulting in limited and possibly outdated insights. Further research, including systematic literature reviews, input from clinicians and health economists, and real-world evidence, is recommended to inform key evidence gaps prior to developing a NICE reference case extension in mental health disorders.