Elicitation of health state utilities associated with varying severities of flares in Systemic Lupus Erythematosus.

C Pollard,S Liu Leage,M.A Paget,S Hartz,A Enstone,J Cook

doi:10.1186/s12955-015-0262-0

Abstract

BackgroundSystemic Lupus Erythematosus (SLE) is characterised by fluctuating periods of minimal disease activity and ‘flare’. Flare is an important outcome variable impacting the disease burden associated with SLE. The objective of this study was to obtain population-based utility values for varying severities of flare to measure the impact on health-related quality of life (HRQoL) in Australia, Canada, France, Japan, Spain and the UK.MethodsSix health states (HS) for varying severities of flare were developed based on literature, patient blogs, and interviews with patients (n = 12), rheumatologists (n = 7) and nurses (n = 2). HS were validated by independent clinical experts (n = 6) and pilot interviews (n = 10, UK). HS were evaluated using the time-trade-off (TTO) method during face-to-face interviews with a minimum representative sample (n = 100) of the general population, per-country. Visual Analog Scale (VAS) scores were obtained to validate TTO scores. TTO scores were converted into utility values.ResultsThe highest mean TTO utility scores were observed for the anchor HS (minimal disease activity) across all countries; means ranged from 0.66 in Japan to 0.82 in UK. All flare HS were associated with a disutility compared with the anchor HS (p < 0.001), means ranged across countries: mild flare HS: 0.55–0.71, moderate flare HS: 0.38–0.53, severe renal flare HS: 0.33–0.45, severe central nervous system (CNS) flare HS: 0.30–0.45 and severe generalised flare HS: 0.19–0.33. Mean VAS scores followed the same trend.ConclusionsThese results show increasing severity of flare has a detrimental impact on HRQoL. The severe generalised flare HS received the lowest mean utility score suggesting that the perceived day-to-day impact of a severe generalised flare was greater than a severe CNS or severe renal flare. This is, to the best of our knowledge, the first utility study to assess varying severities of flare in SLE across six different countries.

Highlights

Systemic Lupus Erythematosus (SLE) is characterised by fluctuating periods of minimal disease activity and ‘flare’
European quality of life- 5 dimensions (EQ-5D) data collected within randomised controlled trials may not optimally capture the disutility associated with SLE flares [20] when administered at set time points which may not have coincided with a patient experiencing a flare
Study population In total 619 interviews were conducted across six countries, there were no instances of participants refusing to complete the TTO exercise; scores were recorded for all participants

Summary

Introduction

Systemic Lupus Erythematosus (SLE) is characterised by fluctuating periods of minimal disease activity and ‘flare’. Flare is an important outcome variable impacting the disease burden associated with SLE. Systemic Lupus Erythematosus (SLE) is a chronic, multisystem, autoimmune disease which predominantly affects women (>90 %) [1]. SLE is associated with the inflammation and subsequent damage of multiple organ systems, notably the skin, joints, heart, lungs, kidneys and central nervous system (CNS) [1]. SLE is characterised by periods of fluctuating disease activity, a patient can experience periods of minimal disease activity and periods of ‘flare’ [1]. Management of SLE is increasingly aimed at the minimisation of disease activity or treatment-related adverse events which may contribute to irreversible organ damage and an increase in co-morbidities [5, 6, 7]

Objectives

Methods

Results