Background: Dual antiplatelet therapy (DAPT) is the recommended preventative treatment for secondary ischaemic events, but increases the risk of bleeding, potentially affecting patients' health-related quality-of-life (HRQoL). Varied utility decrements have been used in cost-effectiveness models assessing alternative DAPT regimens, but it is unclear which of these decrements are most appropriate. Therefore, we reviewed existing sources of utility decrements for bleeds in patients receiving DAPT and undertook primary research to estimate utility decrements through a patient elicitation exercise using vignettes and the EuroQol EQ-5D.
Methods: MEDLINE, PubMed and references of included studies were searched. Primary research and decision analytic modelling studies reporting utility decrements for bleeds related to DAPT were considered. For the primary research study, 21 participants completed an elicitation exercise involving vignettes describing minor and major bleeds and the EQ-5D-3 L and EQ-5D-5 L. Utility decrements were derived using linear regression and compared to existing estimates.
Results: Four hundred forty-two citations were screened, of which 12 studies were included for review. Reported utility decrements ranged from - 0.002 to - 0.03 for minor bleeds and - 0.007 to - 0.05 for major bleeds. Data sources used to estimate the decrements, however, lacked relevance to our population group and few studies adequately reported details of their measurement and valuation approaches. No study completely adhered to reimbursement agency requirements in the UK according to the National Institute for Health and Care Excellence reference case. Our primary research elicited utility decrements overlapped existing estimates, ranging from - 0.000848 to - 0.00828 for minor bleeds and - 0.0187 to - 0.0621 for major bleeds. However, the magnitude of difference depended on the instrument, estimation method and valuation approach applied.
Conclusions: Several sources of utility decrements for bleeds are available for use in cost-effectiveness analyses, but are of limited quality and relevance. Our elicitation exercise has derived utility decrements from a relevant patient population, based on standardised definitions of minor and major bleeding events, using a validated HRQoL instrument and have been valued using general population tariffs. We suggest that our utility decrements be used in future cost-effectiveness analyses of DAPT.
Keywords: Aspirin; Clopidogrel; EQ-5D; Health state utility values; Prasugrel; Ticagrelor; Utility decrements.