Consideration of quality of life in the health technology assessments of rare disease treatments

Objectives: Challenges with patient-reported outcome (PRO) evidence and health state utility values (HSUVs) in rare diseases exist due to small, heterogeneous populations, lack of disease knowledge and early onset. To better incorporate quality of life (QoL) into Health Technology Assessment, a clearer understanding of these challenges is needed. Methods: NICE appraisals of non-oncology treatments with an EMA orphan designation (n=24), and corresponding appraisals in the Netherlands, France, and Germany were included. Document analysis of appraisal reports investigated how PROs/HSUVs influenced decision-making and was representative of QoL impact of condition and treatment. Results: PRO evidence was not included in 6/24 NICE appraisals. When included, it either failed to demonstrate change, capture domains important for patients, or was uncertain. In the other countries, little information was reported and evidence largely did not demonstrate change. In NICE appraisals, HSUVs were derived through the collection of EQ-5D data (7/24 cases), mapping (6/24), vignettes (5/24), and published literature or other techniques (6/24). The majority did not use data collected alongside clinical trials. Few measures demonstrated significant change due to lack of sensitivity or face validity, short-term data, or implausible health states. In 8/24 NICE appraisals, patient surveys or input during appraisal committee meetings supported the interpretation of uncertainty or provided evidence about QoL. Conclusions: This study sheds light on the nature of PRO evidence in rare diseases and associated challenges. Results emphasise the need for improved development and use of PRO/HSUVs. Other forms of evidence and expert input are crucial to support better appraisal of uncertain or missing evidence.