A health-related outcomes set has been developed for familial hypercholesterolemia (FH) patients. • This set contained both outcomes defined by health care professionals as patient-related outcomes (PROMS). • The response rate of the PROMS was 81.4%, implicating high acceptance.• Sufficient knowledge of a patient was associated with better health-outcomes. A R T I C L E I N F O Keywords:Familial hypercholesterolemia Value-based health care Patient-reported outcome measures Prevention Cardiovascular disease A B S T R A C TBackground and aims: Familial hypercholesterolemia (FH) is the most common hereditary lipid disorder requiring life-long treatment to prevent cardiovascular disease. A recent concept in healthcare is not only to focus on outcomes defined by healthcare professionals, but also take Patient-Reported Outcomes Measures (PROMs) into account. The aim of this study is (1) to describe the development and first results of a health-related outcomes set including PROMs for FH patients and (2) investigate the influence of patient knowledge on healthrelated outcomes. Methods: A multidisciplinary group of FH experts, in collaboration with a sounding board of FH patients (n = 166), developed a health-related outcomes set containing the domains: medication adherence (MARS-5), smoking, self-efficacy and self-management, quality of life (QOL) (EQ-5D-5L), reported adverse drug reactions, lipid outcome measures, and FH and cardiovascular risk factor knowledge. Knowledge scores ranged from 0 to 10. Two groups were created: Insufficient knowledge (INSUF) (< 7.5), and Sufficient knowledge (SUF) (≥7.5). Results: The response rate of the questionnaires was 81.4% (n = 429), implicating acceptance of PROMs. In general, FH patients showed good knowledge, high QOL and were adherent to medication. However, the INSUF group had higher triglycerides levels (1.0 vs 0.9, p < 0.05), lower QOL (0.89 [0.79, 1.00] vs 0.89 [0.85, 1.00], p < 0.05), were more often smokers (14% vs 7%, p < 0.05) and reported more adverse drug reactions (62% vs. 49%, p < 0.05). Conclusions: A health-related outcomes set for FH patients, including PROMs, has been developed, which shows that insufficient knowledge of FH is negatively related to health outcomes. Improving patients' knowledge of FH may lead to better health.