Quality of life (QOL) is a critical, prevalent, and enduring concept in oncology nursing research and practice. QOL is a paramount issue in the consideration of treatment, goal planning, and decision making for individuals with cancer, their families, and their care providers. Journals, well-developed valid and reliable instruments, and multiple conceptual models and frameworks are devoted to QOL. This column will review two broad conceptual aspects to consider in relation to QOL. First, conceptual considerations will be discussed for the definition and measurement of QOL. Second, conceptual issues related to QOL as an outcome will be discussed.
The inaugural column of Conceptual Foundations (Flannery, 2016) discussed the role of theory in research and the various ways theory is threaded into the different sections of an article from the background (introducing definitions, explaining theoretical predictions and relationships), to method and measurement (Does the method match the theory, are the measures consistent/congruent with the definitions of the concept?), through results (Was the analysis consistent with the relationships the theoretical model predicts?), to the interpretation and discussion (Were results and implications consistent with the conceptual framework?). Because the concept of quality of life (QOL) is so frequently mentioned in oncology nursing, it will be used as an exemplar for how to think about these issues. For Oncology Nursing Forum (ONF) reviewers and critical readers, thinking conceptually about an article focused on QOL can assist in sorting out whether the article “hangs together.”
A PubMed search limited to ONF articles and a title including quality of life resulted in a total of 151 articles from 1981–2017; 77 (51%) of these articles were published since 2006 and 38 (25%) since 2011. The articles are most frequently original research reports, but also include literature reviews. Findings indicate the importance of QOL to ONF authors, reviewers, and readership.
QOL is an abstract concept. It has been defined in various ways, but all definitions share the idea of multidimensionality and subjectivity. Multidimensional means that more than one aspect is present. Subjective means that QOL is influenced by personal factors and needs to be assessed and measured by asking the individual. Several well-established sources are available for defining the concept of QOL and can be found in Figure 1.
QOL is acknowledged as an abstract and multidimensional concept and, within the oncology literature, there is broad consensus on the dimensions of QOL. However, variation exists in the naming and number of these dimensions. The four domains of QOL include physical, psychological, social, and spiritual well-being, as outlined in a QOL model by Padilla, Ferrell, Grant, and Rhiner (1990). This conceptual model of QOL has received considerable attention, testing, and refinement to specific oncology populations. Measurement instruments of the QOL scale have been developed for a range of cancer populations congruent with this conceptual model, including items for all four dimensions (Ferrell, Hassey-Dow, & Grant, 2012).
Two additional conceptualizations of the dimensions of QOL and the associated measurement instruments include the Functional Assessment of Cancer Therapy (FACT) and the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ). These approaches were selected because of their prevalence in the literature and their relevance to oncology nursing.
Functional Assessment of Cancer Therapy: Developed by Cella et al. (1993), the FACT and the Functional Assessment Chronic Illness Therapy (FACIT) are used to measure QOL in patients with cancer. The dimensions included in the FACT scales are physical, social, emotional, and functional well-being. Items for all four of these dimensions are included in the scale.
European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire: Another commonly used measurement for QOL in oncology research is the EORTC QLQ. The dimensions in this measure include physical functioning, role functioning, emotional functioning, cognitive functioning, social functioning, and global QOL. The FACT/FACIT and EORTC QLC have multiple measures that have been developed for specific populations.
The conceptual definition, if provided, is a framework for manuscript reviewers to understand and evaluate what comes next in the research article. If the conceptualization of QOL is presented as multidimensional, does the instrument that is used include all of the dimensions of the conceptual framework of the study? Is an existing conceptual model for QOL used and presented? One conceptual aspect to examine is if there is a match between how QOL is defined and how it is measured. Does the researcher propose an improvement in QOL based on his or her research and, if so, is there a change in overall QOL score? Alternatively, subscale scores may be examined and used to discuss changes in QOL. A discerning reader may note that there is only a change to one dimension of QOL rather than a change to the overall global concept.
The second conceptual issue to consider is the theoretical model or framework for how QOL is related to other concepts. Most often, QOL is conceptualized as the primary outcome variable in research studies. A systematic review of health-related QOL models by Bakas et al. (2012) reported a wide range of models and derivations of models in use and recommended using an existing framework unless there was compelling research for a new model. The most frequently cited model for health-related QOL is Wilson and Cleary’s (1995) framework. This model was revised to specifically facilitate its use in nursing and health research by Ferrans, Zerwic, Wilbur, and Larson (2005). This revised model was recommended for use in the review article.
The revised framework (Ferrans et al., 2005) identifies five central concepts: (a) biological function, which leads to (b) symptoms, which leads to (c) functional status, which leads to (d) general health perception, which leads to (e) QOL. Surrounding these concepts are characteristics of the individual and characteristics of the environment—two concepts that interact with all of the five central features. The model provides a framework that can be used to hypothesize relationships among variables and design interventions. The conceptual framework for QOL, if provided, allows reviewers and readers to identify the proposed relationships for influencing, changing, and improving QOL.
QOL remains a central concept of interest to oncology nurses. Two broad conceptual issues that are relevant to QOL were presented in this article. The first is how QOL is conceptualized: What are the dimensions, and is the measurement congruent? Second, a framework for understanding QOL in relation to other variables was presented. Research on QOL is extensive, and multiple conceptual models and frameworks have been developed. Use of established frameworks and scales is recommended for continuing to advance the field.
Flannery is an assistant professor in the School of Nursing at the University of Rochester in New York. No financial relationships to disclose. Flannery can be reached at firstname.lastname@example.org, with copy to editor at ONFEditor@ons.org.
Bakas, T., McLennon, S.M., Carpenter, J.S., Buelow, J.M., Otte, J.L., Hanna, K.M., . . . Welch, J.L. (2012). Systematic view of health-related quality of life models. Health and Quality of Life Outcomes, 10, 134. doi:10.1186/1477-7525-10-134
Cella, D., Tulsky, D.S., Gray, G., Sarafian, B., Linn, E., Bonomi, A., . . . Brannon, J. (1993). The Functional Assessment of Cancer Therapy scale: Development and validation of the general measure. Journal of Clinical Oncology, 11, 570–579.
Ferrans, C.E., Zerwic, J.J., Wilbur, J.E., & Larson, J.L. (2005). Conceptual model of health-related quality of life. Journal of Nursing Scholarship, 37, 336–342.
Ferrell, B.R., Hassey-Dow, K., & Grant, M. (2012). Quality of Life Patient/Cancer Survivor Version (QOL-CSV): Measurement instrument database for the social science. Retrieved from http://www.midss.org/sites/default/files/qol-cs.pdf
Flannery, M. (2016). Explicit assumptions about knowing. Oncology Nursing Forum, 43, 245–247. doi:10.1188/16.ONF.245-247
Padilla, G., Ferrell, B., Grant, M., & Rhiner, M. (1990). Defining the content domain of quality of life for cancer patients with pain. Cancer Nursing, 13, 108–115.
Wilson, I.B., & Cleary, P.D. (1995). Linking clinical variables with health-related quality of life: A conceptual model of patient outcomes. JAMA, 273, 59–65.