PRO150 A SYSTEMATIC LITERATURE REVIEW OF HEALTH STATE UTILITY VALUATIONS IN HAEMOPHILIA

Abstract

Health state utility values (HSUVs) are an important input to economic evaluations. This systematic literature review (SLR) evaluated HSUVs for people with haemophilia (PWH) to facilitate the economic evaluation of novel treatments being developed, including gene therapies. Building on a previous review (Grosse et al. 2015), we conducted a SLR to March 2019 through a search of electronic databases, including MEDLINE®, Web of Science, Cochrane Library, and the School of Health and Related Research Health Utilities Database (SCHARRHUD). Major clinical, patient, and pharmacoeconomic conferences in 2016-2019 were also queried. Studies were double screened by independent reviewers, after which data extraction was performed. Of 1,511 titles and abstracts screened, 20 studies and 12 conference abstracts were included. The studies identified applied a mix of direct and indirect health utility elicitation techniques. Two studies applied direct time trade-off (TTO) methodology and the remaining 30 studies adopted indirect valuation methodologies. HSUVs were found to decrease with increasing disease severity. For example, in Hoxer et al. (2018), mean (standard deviation) HSUV were 0.80 (0.21), 0.73 (0.22) and 0.67 (0.25) in people with mild, moderate, and severe haemophilia, respectively. Utility values were also found to vary by severity of musculoskeletal damage, bleed frequency, inhibitors, haemophilia subtype, treatment regimen and adherence. Interestingly, HSUVs derived from valuations from the general public were found to be valued lower than those derived from PWH for similar health states. For example, in Carlsson et al. (2017), general population participants consistently rated significantly lower HSUVs for haemophilia disease states compared to PWH (range: 0.54-0.60 vs. 0.67-0.73). This SLR shows significant impact of haemophilia on health utilities among PWH. The substantial humanistic burden experienced by PWH highlights unmet needs remaining in haemophilia. Our review findings also suggest potential disease state adaptation among PWH, which warrants further research using robust patient preference studies.