Background: Decisions on the cost-effectiveness of healthcare interventions for multiple sclerosis (MS) are often based on costper- QALY data. QALY weights (values) for MS have commonly been derived using health state values from general population preferences for health states, combined with cross-sectional health status data from patient groups, introducing potential for bias. Therefore using these QALY data may introduce limitations, and can hamper decision-making regarding funding of MS treatments. Aims: To present health state values (HSVs) of MS health states using data from a prospective, longitudinal, cohort study. Methods: Data from a large UK cohort study for MS, the South West Impact of MS (SWIMS) Study, were used for analysis. SWIMS data comprise six-monthly self-report assessments, including EQ-5D and SF-36 health status measures, and data on relapse frequency/severity. Self-report data is supplemented with data from clinician assessment of disability using the EDSS. Health state valuation data, typically used in the context of values from 0 (equiv to death) to 1 (equiv to full health), are sourced from published UK tariffs to present values for MS against EDSS, relapse characteristics, and against other disease related characteristics. Results: Analyses of SWIMS data included 1,441 respondents, over an average of 8 time-points. Findings on health state values show a health profile that worsens by disease progression, against EDSS stages, using both the EQ-5D and SF-6D methods. Health state values estimated from EQ-5D data range from 0.76 at EDSS stage 1.0 to 0.03 at EDSS stage 8, with lower values seen for progressive MS. Values estimated from SF-36 data reflect the narrower range of values possible on the SF6D tariffs, with values from 0.7 to 0.53 across EDSS stages 1.0 to 8. Findings demonstrate impact on health state values due to relapse events, with this impact reported at 0.08 using the EQ-5D and at 0.05 using the SF-6D. The impact of relapse frequency, severity and endurance on health has also been assessed. Conclusions: This is the first study to present data on health state values for MS from a longitudinal cohort study, and to present data on SF-6D values for MS. Health state values (QALY weights) for features of relapses have not been previously reported. This data can support improvements in the conduct of cost-effectiveness analyses of treatments for MS, and in a more general health policy context.
Green, C., Hawton, A., & Zajicek, J. (2013). Health State (QALY) Values for Multiple Sclerosis: A Report Using Data from the United Kingdom South West Impact of Multiple Sclerosis (SWIMS) Study. Value in Health, 16(7), A625. https://doi.org/10.1016/j.jval.2013.08.1837