Representations of control and psychological symptoms in couples dealing with cancer: A dyadic-regulation approach

Abstract

The aim of this study was to examine the relation between illness representations of personal and treatment control and psychological symptoms (i.e. symptoms of anxiety and depression) in 72 married couples dealing with a recently diagnosed cancer. Patients were first-diagnosed with early stage (45.83%) or metastatic cancer (54.17%). Dyadic responses were examined with the actor–partner interdependence model. Also, in order to examine whether patients and spouses’ representations of control moderate the relation of their partners’ corresponding representations to psychological symptoms, we used the relevant bootstrapping framework developed by Hayes and Matthes [(2009). Computational procedures for probing interactions in OLS and logistic regression: SPSS and SAS implementations. Behavior Research Methods, 41, 924–936]. Patients’ symptoms of anxiety and depression were associated with both partners’ representations of control. Chi-square difference tests indicated that actor and partner effects were equal. Spouses’ symptoms of anxiety and depression were related only to their own representations. Moreover, spouses’ representations of personal control moderated the relation of patients’ corresponding representations to depressive symptoms, whereas patients’ representations of treatment control moderated the relation of their spouses’ corresponding representations to both anxiety and depression. Findings suggest that both partners’ representations of control are important for adaptation to illness. Moreover, they indicate that dyadic regulation may be equally important to self-regulation as far as adaptation to illness is concerned.

Keywords:

• couples’ adaptation to illness
• dyadic regulation
• cancer

Notes

Notes

1. The number of participants was ascertained a priori using the G*Power program. G*Power is free of charge via the Internet power analysis program which is based, among others, on Cohen's (1988) conventions regarding statistical power (Erdfelder, Faul, Buchner, Lang, 2009; Faul, Erdfelder, Lang, & Buchner, 2007). In an a priori power analysis, the necessary sample size is computed as a function of user-specified values for the required significance level α, the desired statistical power 1 – β and the to-be-detected population effect size (Erdfelder et al., 2009). According to this, for the identification of a significant single regression coefficient (as examined in this study with the use of SEM and multiple regression analyses) at an alpha level equal to 5%, a medium effect size, a desired statistical power equal to 0.95 and a maximum of eight predictors (as in this study), a sample of about 75 couples was needed. Our final sample of 72 couples was very close to that estimation (post hoc analysis using G*Power revealed a statistical power equal to 0.946). Thus, adequate levels of power were available for the identification of medium effects.

2. Preliminary analyses showed that patients’ age was tentatively related to their own representations of personal control in a positive way, and with own anxiety in a negative way (ps < 0.10). Male patients reported higher levels of personal (p < 0.05) and treatment control (p < 0.10), as well as more depressive symptoms (p < 0.05). Metastatic cancer was associated with lower levels of patients’ representations of personal control, as well as with higher levels of patients and spouses’ anxiety and depression symptoms (ps < 0.05). The overall quality of life (see Table 1) was related to patients’ representations of personal control (p < 0.05) and tentatively to both partners’ depression symptoms (ps < 0.10).