To the best of our knowledge, this is the first time data from a population-based consecutive cross-sectional Swedish study cohort has been used to show that psychological resilience is associated with HRQoL in women with newly diagnosed BC. The study indicates that at the time of receiving the diagnosis, both psychological resilience and HRQoL scores are lower than those from population-based data.
The results are consistent with the findings of prior studies [8, 11, 12, 18–20] demonstrating the possible need for psychosocial support of BC patients as most of the women presented lower levels of psychological resilience compared to normative data reported by Connor and Davidson [15]. The present study included a cohort of 517 Swedish women with a mean psychological resilience score of 70.6 at the time of diagnosis. The mean CD-RISC25 score varied between 54.7 and 74.7 in earlier studies [8, 11, 12, 18, 19, 20]. Markovitz et al. (2015) reported higher levels of psychological resilience, 93.8, compared to other BC studies [14]. However, they used a 1- to 5-point Likert scale instead of the recommended 0- to 4-point Likert scale [15–16]. On the website of the CD-RISC25 authors, the mean score for the BC cohort in the study by Markovitz et al. [16] was recalculated to 68.8, which is close to the mean score in this study.
As psychological resilience is assumed to be a dynamic process, minor variations across BC studies can be explained by differences in the timing of the CD-RISC25 assessment [11, 13]. The time span from diagnosis to CD-RISC25 assessment differs widely in the reported studies [8, 11, 12, 18]. This indicates that some women were affected by events linked to the treatment, while others more or less had recovered their levels of psychological resilience at the time they completed the CD-RISC25. Likewise, the women included in the present study may already have been affected by the diagnostic work-up for suspected BC. Although the information about diagnosis and treatment was given right before they responded to the instruments, it is reasonable to assume that they were aware at that time that something was wrong. The diagnostic work-up was conducted two to three weeks before the consultation, and the women were advised to bring someone close to them. Similarly, BC patients in previous studies scored even lower on psychological resilience when it was measured close to therapy [11, 19, 20]. Other than the present study, Markovitz et al. (2015) is the only BC study to report a distinct time of inclusion [14]. In this Belgic BC cohort, psychological resilience was measured at the time of primary surgery, one to two weeks after the women had been informed of the diagnosis, and the mean score is in line with the results of this study. Our results indicate that as soon as at the time of the BC diagnosis, some women may need psychosocial support because the levels of psychological resilience at this early time point were lower than those based on population data [15].
HRQoL (GH, SF, RE and MH) was lower in the investigated women compared with Swedish normative data [21]. It is fair to assume, as with psychological resilience, that the fear of BC during the diagnostic work-up had already had an impact on the patients’ HRQoL at the time of the diagnosis. Only a few of the previous BC studies have explored HRQoL in relation to psychological resilience, although they did not use the SF–36 [8, 10]. Despite differences in the instruments chosen, the similarities between the results of our study and those of Ristevska-Dimitrovska et al. (2015) and Zhang et al. (2017) are a striking demonstration that higher levels of psychological resilience correspond to higher levels of HRQoL [8, 10]. In this study, significant correlations between the CD-RISC25 and all eight domains of the SF–36 were found. This agrees with findings reported by Ristevska-Dimitrovska et al. that psychological resilience is correlated to most aspects of HRQoL in Macedonian BC patients [10]. Additionally, Zhang et al. showed that psychological resilience was correlated with HRQoL in a Chinese cohort [8]. Using another measure for psychological resilience, Harms et al. (2018) found an association between the Protective Factors for Resilience Scale (PFRS) and the SF–36 in a cancer cohort that included BC patients [4]. Harms et al. demonstrated that the correlations between the psychological aspects of the SF–36 and the PFRS were stronger than the correlations between most of the physical aspects of the SF–36 [4]. The results of this study are consistent with those of Harms et al. as the strongest correlations in Swedish women were noted between the CD-RISC25 and GH, followed by the psychological aspects of the SF–36 (MH, VT, SF and RE).
The findings also indicate a significant relationship between psychological resilience and social network and menstrual status. Consequently, variables assumed to be related to psychological resilience, e.g., social network, were included in the multiple regression analyses. Wu et al. (2017) [11] investigated predictors of psychological resilience among Chinese women and found that age was negatively correlated with psychological resilience, which is in line with our finding that postmenopausal women had lower scores than premenopausal women. Similarly, Zhang et al. (2017), Huang et al. (2019) and Alizadeh et al. (2018) presented significant relationships between psychological resilience and social support/network in Chinese and Iranian women [8, 19, 20]. The regression analyses in this study demonstrated that the CD-RISC was significantly associated with each of the eight domains of the SF–36 in terms of both unadjusted models and models adjusted for demographic and clinicopathological factors. Social network and menstrual status tended to have more confounding effects than the other variables, including the stage of BC. After adjustment for social network and menstrual status, most of the coefficients for the CD-RISC25 did not distinctly change. Although psychological resilience was significantly regressed on all domains of the SF–36, the strongest impact of psychological resilience was again demonstrated on GH and the psychological aspects of the SF–36. Higher levels of psychological resilience can be considered to be a potential protective factor among Swedish BC patients for preserving their HRQoL in the context of adversity. Lower levels are a risk factor for emotional distress and impaired HRQoL [10, 14, 18].
The mean score of 70.6 with a SD of 12.7 in the study cohort indicates that a fair share of the women included had a level of psychological resilience lower than 58 (approximately 15% of the population). The application of a threshold of 58, which corresponds to less than 1 SD below the mean score, may identify patients in need of psychosocial support at this early stage. The understanding that psychological resilience is associated with HRQoL in Swedish BC patients could be clinically important in the future development of rehabilitation interventions. Improved knowledge of this association would present an opportunity to develop evidence-based interventions for those presenting lower levels of psychological resilience at the time of BC diagnosis.
More knowledge on psychological resilience in Swedish women with BC is needed, such as Swedish normative data for the CD-RISC25. Longitudinal studies are required in which changes in psychological resilience can be observed over time. Qualitative studies are necessary to describe psychological resilience more extensively. Because of the cross-sectional design of the present study, causal relationships between psychological resilience and other variables of BC patients cannot be established. Further limitations are the non-inclusion rate of approximately 30%. One reason women declined to take part in this study was experiencing too much stress after the BC diagnosis. It is possible that the most stressed patients might be the women with the lowest levels of psychological resilience, which could bias the results of this study towards patients with higher levels of psychological resilience.
Although this study had limitations, it is one of the largest studies published to date regarding psychological resilience and HRQoL in BC patients. Another strength is the adjustment for other variables that may influence HRQoL in these women. All patients were included at the time of diagnosis in the population-based SCAN-B study [22, 23]. Such early and coherent assessment of psychological resilience in relation to BC diagnosis has not been previously presented.