Self-rated health (SRH) is a salient general health status indicator for cancer survivors because it indicates a set of robust clinical outcomes, including cancer patients’ ability to manage and cope with treatment-related symptoms, quality of life, and mortality [1
]. SRH is a significant patient-reported outcome measure (PROM) among cancer patients, which has the strongest predictive validity for health status when compared with any other single-item health rating question, such as physicians’ assessment or BMI [1
]. Therefore, it is essential for oncology providers to shift from a physician-centered approach to patient-centered medicine, especially when promoting the general health status of individuals diagnosed with cancer during and after their treatment [6
]. A compelling body of social determinants of health literature has identified that demographic, e.g., race and socioeconomic status, and psychosocial factors, e.g., depression and social support, are significant predictors of SRH among cancer survivors [9
]. Depression, a prevalent mental health condition among cancer survivors, is negatively associated with SRH [12
]. One emerging theory explicitly linking depression and low SRH is psychoneuroimmunology [14
], which articulates that depressed mood triggers chronic stress and, through neuroendocrine pathways, impacts individuals’ immune system so that individuals are likely to report low SRH as depression worsens [15
]. Education, one of the key variables representing individual socioeconomic status, is another established factor associated with cancer survivors’ SRH [2
]. Individuals with higher levels of education are expected to have better access to healthcare resources and are likely to report a higher level of SRH [16
Despite the well-studied direct association between depression, education, and cancer survivors’ SRH, few studies have evaluated the dynamic interaction between depression and education concerning cancer survivors’ SRH, also known as a pathoplastic relationship [18
]. Pathoplasticity is a theoretical framework that emphasizes the role of an individual’s acquired personality (e.g., temperament, interpersonal style, and cultural influence) in the manifestation of psychological disorders, such as onset, chronicity, and symptom severity [18
]. Educational attainment has been associated with different expressions of depressive disorders [20
]. For example, Di Florio and colleagues [20
] found that higher education is positively associated with more severe expressions of depression, e.g., feelings of being scared or panicky and suicidal ideation, whereas those with low education are more likely to report a different symptom profile, such as anhedonia and guilty feelings. Similarly, Gan and colleagues [21
] found that more years of education is associated with apathy and hypersomnia, as well as a greater chance of recurrent major depressive disorder, suggesting that educational attainment may not be protective, but instead a risk factor, for individuals with depression.
When available theoretical and empirical evidence is taken together, the pathoplastic relationship between depression and education underscores the necessity to evaluate further their impact in relation to SRH on cancer survivors. It is essential to evaluate beyond the direct association between depression, education, and SRH and explore the possible pathoplastic moderating role of education on the association between depression and SRH in cancer survivors. Thus, in addition to the positive direct association between education and cancer survivors’ SRH, evaluating the potential influence of education on the relationship between depression and SRH among cancer survivors is warranted. Using a national representative dataset, the National Health Interview Survey, this study aims to test the following hypotheses: (1) cancer survivors’ depressive mood is negatively associated with SRH; (2) cancer survivors’ education is positively associated with SRH; and (3) to explore whether and how education moderates the association between depressive mood and cancer survivors’ SRH.
To our knowledge, this study is among the first to investigate the pathoplastic moderating effect of education on the association between depressive mood and SRH among U.S. cancer survivors using a national representative dataset. In addition to confirming the robust literature on social determinants of health articulating the negative impact of depressive mood and the protective impact of education on cancer survivors’ SRH [31
], this study reveals that the negative association between depressive mood and SRH is significantly greater among U.S. cancer survivors with higher levels of education, i.e., bachelor’s degree or higher, when compared to their counterparts with below high school education.
Given the well-established protective role of educational attainment for SRH, it is reasonable to anticipate that, for cancer survivors, the negative impact of depressive mood on SRH may become weaker among those with a higher level of education, i.e., education buffers the harmful effect of depressive mood on SRH. However, the findings of this study reveal a converse relationship in that the negative association between depressive mood and SRH is significantly stronger among those with higher levels of education. Thus, even though higher education is a protective factor of SRH among cancer survivors, SRH among those with higher education was found to be more vulnerable to depressive mood than those with lower education.
As indicated earlier in the introduction, education’s dual role as a “protective-risk” factor for SRH among cancer survivors is pathoplastic in nature [18
]. While cancer survivors’ educational attainment, in general, protects individuals from depression and improves their SRH, individuals with high levels of education are more likely to experience severe and recurrent episodes of major depression than their counterparts with low levels of education. Thus, for cancer survivors who are depressed, those with high levels of education are likely to manifest more severe depressive symptomologies than their peers with low levels of education. The specific mechanism articulating how educational attainment impacts cancer survivors’ personalities and, consequently, interacts with their depressive disorders is beyond the scope of this paper and should be further evaluated. The findings of this study articulate the importance of accounting for pathoplasticity combined with the social determinants of health frameworks, such as education, when evaluating the relationship between depressive mood and SRH among cancer survivors.
In addition to the pathoplastic influence of education on cancer survivors’ SRH, the findings of this study may be explained by the varied coping behaviors among cancer survivors with different educational backgrounds. For example, studies have reported that individuals with a higher level of education are more likely to use rumination and self-criticism to cope with depression [33
]. Cancer survivors who continue to face a sequela of side- and late-effects due to cancer treatment tend to experience a greater risk of worsening mood when ruminating on their negative emotions and perceived poor health, which is often caused by cancer treatment-related symptoms such as pain, fatigue, or insomnia. As a result, cancer survivors who often use rumination and self-criticism to cope with depression, i.e., those with higher educational attainment, are more likely to have worse depression and lower self-rated health.
Several limitations should be noted. First, this study is cross-sectional and cannot infer causality, limiting the internal validity of study findings. This highlights the need for future longitudinal and national representative studies of cancer survivors to confirm these findings. Second, this study only included participants representative of U.S. adult cancer survivors who are 18 years or older; thus, findings are only generalizable to adult cancer survivors. Separate investigations focusing on pediatric, adolescent, and young adult cancer survivors are warranted to determine if these findings are replicable for younger cancer survivors. Third, cancer survivors’ depressive mood was evaluated using PHQ-8. Although with high validity and reliability, PHQ-8 does not provide diagnostic information of an individual’s clinical depression, another limitation of this present investigation. Finally, the dataset does not contain variables that indicate a cancer survivor’s current treatment stage, history of depression, or chronicity of current depression, all of which are important clinical covariates that should be accounted for when these variables become available.
Despite these limitations, the results of this study have important clinical implications for psycho-oncology providers. When working with cancer survivors who experience depression and low SRH, the assessment of social determinants of health remains an essential component in understanding cancer survivors’ general health status in order to ensure cancer survivors’ quality of life. More importantly, psycho-oncologists should extend beyond the direct protective impact of education on SRH among cancer survivors, especially given the pathoplastic moderating role of education on the relationship between depressive mood and SRH. Differential consideration is warranted for the role of educational attainment among cancer survivors with or without a depression diagnosis. While it is reasonable to view education as a protective factor for cancer survivors with cancer, psycho-oncology providers should pay particular attention to the symptom profile of depression for depressed cancer survivors with high levels of education.
For oncology providers supporting the general health and mental health wellness of individuals diagnosed with cancer, it is important to (1) account for the pathoplastic impact of education on cancer survivors’ depressive mood and self-rated health, (2) evaluate the depressive symptom profile for individuals diagnosed with cancer, and (3) evaluate specific coping styles of an individual patient diagnosed with cancer to inform the optimum selection and delivery of health and mental health support services [34