Quality-of-life research in the European Journal of Cardiovascular Nursing: A call for more conceptual scrutiny

Quality of life (QoL) is one of the most frequently used patient-reported outcomes in cardiovascular care and beyond. QoL is often measured to appraise the impact of a condition on patients’ life or to evaluate the benefits of different treatment options.1 As a result, the number of articles measuring QoL increased exponentially over the past decades.2 However, QoL is a construct that is not unequivocal. Indeed, there is still no consensus regarding the conceptualization, operational definition and measurement of QoL.2 The lack of a uniform definition for QoL contributes to its conceptual vagueness and obscurity.2 Evidently, interpretation of results from QoL studies is complicated when investigators do not use a consistent conceptual basis to define QoL, or if they do not define QoL at all.2 Last year, Haraldstad and colleagues performed a snapshot review of QoL research in medicine and health sciences.3 The authors reviewed 163 articles on QoL studies that were published in one random week.3 In order to evaluate the conceptual and methodological rigour of the articles, they used 10 evaluation criteria that were developed by Gill and Feinstein in 1994.4 These criteria have been previously applied in evaluations of QoL research in congenital heart disease.5,6 The main conclusion of the Haraldstad review was that the majority of QoL studies in health and medicine have conceptual and methodological challenges.3 QoL research is also prevalent in the European Journal of Cardiovascular Nursing. In 2018–2019, a total of 25 articles have been published, in which QoL was quantitatively assessed.7–31 In order to see how articles in the journal are performing relative to the mainstay of articles published in medical and health sciences literature, the 25 articles were evaluated against the Gill and Feinstein criteria, and compared with the findings of the Haraldstad review. Overall, 20% of the articles provided a definition of QoL; 28% specified the domains of QoL; and in 40% of the articles, the authors provided a reason why they choose that particular instrument (Table 1). The authors aggregated the results into a single composite score in 23% of the papers; and in 16%, the respondents were asked to give their own global rating of QoL. None of the articles complied with the other criteria (Table 1). In comparison with the findings of the Haraldstad review, articles published in the European Journal of Cardiovascular Nursing are doing slightly better than the mainstay of articles in medical and health sciences literature in terms of providing a definition of QoL, giving the reason why the instrument is chosen and asking patients to give their own global rating of QoL. Still, there is room for improvement. Evaluation of methodological and conceptual rigour according to the criteria from Gill and Feinstein.4 EJCN: European Journal of Cardiovascular Nursing; NA: not applicable. Evaluation of methodological and conceptual rigour according to the criteria from Gill and Feinstein.4 EJCN: European Journal of Cardiovascular Nursing; NA: not applicable. To support authors in writing more conceptually rigorous articles, 10 years ago, we published an editorial proposing some minimal requirements for quality-of-life reports.32 Given that there is still room for improvement, it is timely to offer these recommendations to future authors again: Authors are required to provide the definition of quality of life that they have used in their study. This is imperative to make sure that readers understand what the authors mean by the term ‘quality of life’. In addition, it allows reviewers and readers to check whether QoL is not interchanged with other related concepts, such as health status or functional status. Authors are required to explicitly state the domains that they have measured as components of quality of life. QoL is typically considered to be a multidimensional or multifactorial construct. Hence, it comprises multiple domains. The choice of QoL instrument(s) basically relies on the components included in the instrument(s). To determine whether the selected measurement was suitable to assess the desired target, authors should explicitly state which domains they consider to be significant elements of QoL.4 Authors are required to give the reason(s) for choosing the instruments they used. Valid assessments require that the instruments used are suitable for the intended task. Since numerous QoL instruments exist, investigators need to state their reasons for choosing to use a particular instrument or instruments to assess QoL.4 These reasons should ensure that QoL is measured appropriately according to their intended goals. Just because an instrument has good psychometric properties or is widely used does not mean suitable reasons were considered for its use. Authors are required to state whether they measured overall quality of life or health-related quality of life. Health care professionals are predominantly interested in health-related factors to be components of patients’ QoL. However, a holistic approach implies that also non-medical phenomena emerge. Consequently, a distinction between overall and health-related QoL should be made clear in QoL papers.4 Authors are required to explicitly state the indicators and determinants of quality of life that they have measured in their study. Investigators need to stipulate how they have measured QoL itself (by its indicators), and how they have assessed influencing factors (by its determinants). A clear distinction between indicators and determinants of QoL is imperative. Authors who are submitting a QoL report to the European Journal of Cardiovascular Nursing are invited to use these requirements. By doing so, we can improve the conceptual and methodological rigour of QoL studies and expand the knowledge base in this important field of research. The author has no conflicts of interest to declare. The author received no financial support for the research, authorship, and/or publication of this article.