Purpose: Utility values are critical for cost-utility analyses that guide healthcare decisions. We aimed to compare the utility values of the 5-level EuroQoL-5Dimension (EQ-5D-5L) health states elicited from members of the general public and patients with heart disease or cancer.Methods: In face-to-face interviews with 157 heart disease patients, 169 cancer patients, and 169 members from the general population, participants valued 10 EQ-5D-5L health states using a composite Time Trade-Off method.Results: Pooling utility values for all health states, heart disease patients and cancer patients had mean utility values lower by 0.11 points (P value = 0.014) and 0.06 points (P value = 0.148), respectively, compared to the general population. Adjusting for sociodemographic characteristics, differences in health state utility values between the patient and the general populations were rendered non-significant, except that heart disease patients gave higher utility values (mean difference = 0.08; P value = 0.007) to mild health states than the general population. Difference in utility values, defined as utility value of a better health state minus that of a poorer health state, was higher among heart disease patients compared to the general population, before and after adjusting for sociodemographic characteristics.Conclusions: Patients may differ from members of the general population in the strength of their preferences for hypothetical health states. Using utility values derived from the general population may under-estimate the comparative effectiveness of healthcare interventions for certain diseases, such as heart diseases. [ABSTRACT FROM AUTHOR]