Happiness and Eudaimonic Well-Being in Adult Oncology: A Scoping Review of Definitions, Measures, and Clinical Contexts

Background: As cancer is increasingly experienced as a chronic condition, psycho-oncology has moved beyond distress reduction to include broader dimensions of patient well-being. Although happiness, hedonic well-being, and eudaimonic well-being are often used interchangeably, they refer to theoretically distinct constructs: hedonic well-being encompasses life satisfaction and positive affect, whereas eudaimonic well-being is characterized by meaning, purpose, autonomy, and personal growth. This overlap may limit the interpretability and comparability of findings across oncology studies. Objective: This scoping review aimed to map how happiness and eudaimonic well-being have been conceptualized and operationalized in empirical studies involving adult cancer patients. Methods: The review followed the Joanna Briggs Institute methodology for scoping reviews and the PRISMA-ScR reporting guidelines. A systematic search was conducted in PubMed, PsycINFO, Scopus, Web of Science, and CINAHL. Eligible studies were peer-reviewed, English-language, empirical studies of adults with any cancer type or stage that explicitly assessed happiness or eudaimonic well-being. Screening and data extraction were divided between two reviewers, each working independently on an assigned portion of records, with a third reviewer adjudicating indeterminate cases. Results: A total of 108 studies met the eligibility criteria, conducted across 32 countries and published over twenty-seven years. Happiness was defined with relative consistency, drawing almost entirely on Diener's (1984) subjective well-being tradition, but was frequently undefined and measured through instruments ranging from multidimensional questionnaires to single-item ratings. Eudaimonic well-being was the more prominent construct, drawing on several distinct traditions sharing a vocabulary of meaning, purpose, and growth without 5 agreement on its referents; fewer than four in ten studies provided an explicit definition, and this boundary was rarely addressed in the literature. Conclusion: Both constructs are assessed in adult oncology using overlapping and imprecise terminology, and the two dimensions are rarely distinguished. This review proposes an operational definition for each and recommends that future studies explicitly specify the targeted dimension and the assessment instrument used. Keywords: happiness; eudaimonic well-being; hedonic well-being; cancer; psycho-oncology; scoping review; measurement; conceptualization.