The association of illness perception, personal control and social support with psychological distress in GI cancer patients: A comparison between men and women.

The remarkable developments in early diagnosis and treatment of cancer in recent decades have contributed to increased life expectancy and survival rates. Nonetheless, cancer continues to be perceived as life-threatening, with considerable mental distress experienced by patients. Numerous studies have focused on understanding the characteristics and predictors of mental distress. However, most studies centered on the most common types of cancer, mainly breast cancer and prostate cancer, which are gender specific, limiting conclusions regarding gender differences.

The current study examined patients living with all types of gastrointestinal cancer, such as colon, stomach, esophagus and pancreas cancer. Gastrointestinal cancer is one of the leading causes of morbidity and mortality worldwide, with similarrates among men and women; it is therefore suitable for studying gender differences.

Based on the cognitive model of Stress and Coping (Lazarus & Folkman, 1984), the research questions were: 1) Is there is an association between illness perception and distress among gastrointestinal cancer patients; 2) What is the contribution of coping resources to this association: whether a sense of personal control (personal resource) mediates and/or moderates the association between illness perception and distress and whether social support (social resource) moderates this association. 3) Are there gender differences with respect to each of the variables and in the associations between them? 

Method: the study population included 82 male and female gastrointestinal cancer patients undergoing treatment at the Kaplan Medical Center Oncology Institute, about three months or more after having been diagnosed with the disease. The study was approved by the hospital Ethics ReviewCommittee. After signing the informed consent form, the patients were interviewed by a structured questionnaire that included: demographic information; questionnaires for assessing illness perception (Broadbent, Petrie, Main & Weinmam, 2006); mental distress (Derogatis, 2001); sense of personal control (Mastery scale, Pearlin & Schooler, 1978); and social support (Goldzweig et al, 2010). Data regarding objective disease severity were obtained from the patient’s medical file and included: diagnosis type, disease stage and disease severity.

Data analysis included Pearson’s test for bivariate associations, and two-step hierarchical linear regression models on mental distress to test the study hypotheses. In the first step the background control variables were entered, followed by each of the study in the second step. The mediation and moderation hypotheses were tested using the PROCESS procedure developed by Hayes (2013).

Main Study Findings: Bivariate analysis showed a statistically significant association between illness perception and mental distress. The hypothesis that sense of personal control mediates the association between illness perception and mental distress was partially supported: the direct effect between illness perception and mental distress (b=0.22, p<.001) was strengthened when sense of personal control is present (ind.=.026, p<.05). Additionally, the moderating effect of personal control on the association between illness perception and mental distress reached only of borderline statistical significance (β=.02, p=.088). An examination of the sources of the interaction showed a strong positive association between illness perception and mental distress (b=.58, p<.001) among patients with a low sense of personal control, while the association was weaker (b=.30, p=.02) among patients with a high sense of personal control. In contrast, the hypothesis regarding the moderating effect of social support on the association between illness perception and mental distress was not supported.

Examination of the contribution of all variables to mental distress showed that despite the significant bivariate association between each of the coping resources and mental distress was statistically significant, they did not have an additional contribution to mental distress beyond that of illness perception.

Finally, the hypotheses regarding gender differences in the study variables were partially substantiated: a statistically significant difference was found only in mental distress levels, with women reporting higher levels of mental distress compared to men. However no gender differences  in other study variables were found, nor in the associations between them and mental distress.

Discussion and Conclusions: The findings point to the unique contribution of the patients’ subjective cognitive perception of their condition in explaining the variance in mental distress among gastrointestinal cancer patients. They highlight the mediating and moderating effects of sense of personal control on the association between the illness perception and mental distress. On the other hand, the non-significant moderating effect of social support on the association between illness perception and mental distress contradicts the evidence from the literature. The findings regarding gender differences, rarely studied among gastrointestinal cancer patients, are important because lack of gender differences in the study variables, except for mental distress, and in the associations between the study variables, indicates that other factors may contribute to gender differences in predicting mental distress.

The study has limitations due the fact that the subjects were from a single medical center and also owing to the relatively small sample. The study design – a cross sectional study – does not enable conclusions regarding causal association.

The unique contribution of the study is that it underscores the significance of patients’ subjective perception of their disease in explaining mental distress of gastrointestinal cancer patients. This has important implications to practice by contributing to a better understanding of patients’ emotional needs. It is important that all medical and para-medical staff members that come in contact with patients are aware of the significance of the way in which patients view their disease and the direct association between illness perception and mental distress as it may influence patients’ compliance to undergo treatment. The study findings can facilitate the planning of treatment interventions compatible with the patients’ needs, taking into consideration the resources at their disposal, first and foremost their sense of personal control, and ability to mobilize these resources. This awareness on the part of the medical-nursing staff will help identify patients and refer them to psycho-social interventions. These should address the thoughts patients attribute to their disease and their feeling as to their ability to control the disease, while assessing additional coping resources at their disposal.

The study findings point to further implications to research: the need for more in-depth knowledge and understanding of mental distress predictors. It is recommended to reassess the role of social support and to deepen understanding of personality and other variables that shape patients’ perception and explain mental distress. Futher examination of gender differences with respect to these variables is also recommended.