Utility elicitation study in the UK general public for late-stage chronic lymphocytic leukaemia.

Objectives: In the United Kingdom (UK), chronic lymphocytic leukaemia (CLL) makes up 40 % of all leukaemias in patients over 65 years. The study objective was to obtain societal preferences in the UK for "progression-free" and "progressive" states of late-stage CLL, refractory to current first and second line regimens. Preferences were also obtained for selected treatment-related adverse events (AEs).

Methods: A utility elicitation study, using the time trade-off (TTO) method, was conducted by face-to-face interviews with 110 subjects for a baseline disease state (before treatment), three primary disease states [progression-free survival (PFS) and treatment responder, PFS and treatment non-responder and disease progression], and 4 AE sub-states (PFS responder with thrombocytopenia, neutropenia, and infection, and PFS non-responder with infection). TTO scores were converted into utility values, and disutilities were calculated for AEs. Visual analogue scale (VAS) scores were obtained.

Results: The primary disease state mean TTO utility scores were: baseline: 0.549; PFS response: 0.671; PFS non-response: 0.394; and progression: 0.214. The mean TTO utility (disutility) scores for the AEs were: PFS response with thrombocytopenia, 0.563 (-0.108), neutropenia, 0.508 (-0.163), and infection, 0.476 (-0.195); PFS non-response with infection, 0.333 (-0.061). The VAS results were in line with the TTO results.

Conclusions: The utility was higher for the PFS state than baseline, but decreased below baseline in non-response and disease progression states. AEs had an impact on utility within the PFS response state. The severe infection AE had a greater impact on utilities for the responding to treatment state compared to the non-responder state.