What PASSes for good? Experience-based Swedish and hypothetical British EuroQol 5-Dimensions preference sets yield markedly different point estimates and patient acceptable symptom state cut-off values in chronic arthritis patients on TNF blockade

OBJECTIVES: Health utilities derived from answers to generic health-related quality of life (HRQoL) questionnaires such as the EuroQol 5-Dimensions (EQ-5D) are often used in cost-utility analyses (CUAs) of new and expensive treatments. Different preference sets (tariffs) used in the computation of utility values and quality-adjusted life-years (QALYs) from questionnaire responses (health states) yield varying results, potentially affecting decisions of resource allocation. The objective of the present study was to compare British (UK), hypothetical, and Swedish (SE), experience-based, EQ-5D utilities using data from clinical practice.

METHOD: UK and SE EQ-5D utilities were computed in an observational cohort of patients with rheumatoid arthritis (RA), spondyloarthritis (SpA), and psoriatic arthritis (PsA) treated with tumour necrosis factor (TNF) blockers, comparing point estimates and patient acceptable symptom state (PASS) cut-off levels.

RESULTS: SE utilities were found to be consistently higher than UK utilities, and PASS cut-offs were essentially stable over time.

CONCLUSIONS: With higher baseline utilities, there may be less room for improvement after an intervention and thus less accumulation of QALYs in CUAs applying the SE, as opposed to the UK, EQ-5D tariff.