One of the important contributions of this study was that it provided a theory-based, longitudinal analysis of factors associated with the quality of life of both prostate cancer patients and their spouses. This analysis of factors enabled us to examine the process of adjustment over time. Findings indicated that selected antecedent variables measured at baseline had a significant effect on patients’ and spouses’ appraisal at 4 months and on their coping and quality of life outcomes at 8 months.
We tested a modified version of Lazarus’s theoretical model and found that the model accounted for a significant amount of variance in both
prostate cancer patients’ and their spouses’ quality of life. Consistent with Lazarus’s theory, appraisal mediated the effect of the antecedents on quality of life. Although Lazarus’s theory suggests a fully mediated model as shown in , we found that appraisal had both direct and
indirect effects on quality of life. Illness-related factors, such as symptom distress (both patients’ and spouses’) had a direct negative effect on quality of life outcomes, consistent with findings in previous studies (23
Using the APIM analysis to examine patients’ and spouses’ self-assessments in a single analysis, we found more actor effects than partner effects. Thus, patients’ personal, social, and illness-related variables had the most significant effects on their own negative appraisal at 4 months, and ultimately on their own quality of life. Similarly, spouses’ own antecedent factors were more predictive of their own appraisal measures and thus their quality of life.
However, the few observed partner effects were quite interesting. One partner effect that emerged pertained to the age of the spouse. The older the spouse, the more negative appraisal of illness, and uncertainty, that was reported by the patient. Patients may perceive older spouses as more vulnerable to the effects of illness and less able to meet patients’ support needs. Another partner effect that emerged indicated that, when patients reported more baseline symptoms, their spouses reported more hopelessness at 4 months follow-up. This finding is consistent with reports of others who found that, as patients’ symptoms increased, spouses’ mental health decreased (7
). On the other hand, if patients reported more uncertainty, their spouses reported using more active coping strategies, perhaps to create a greater sense of predictability in their lives. These partner effects, as well as the significant relationship found between patients’ and spouses’ mental quality of life, underscore the importance of assessing both patients’ and spouses’ quality of life because each partner affects the well-being of the other.
Of the mediators examined, appraisal served as an important mediator between antecedent variables and quality of life for both patients and spouses. Hopelessness was a mediator for patients’ but not for spouses’ quality of life. Uncertainty did not mediate either patients’ or spouses’ quality of life outcomes, a finding supported in an earlier study of breast cancer patients and their partners (23
). It may be more accurate to view uncertainty as an outcome (endpoint) rather than as a mediator of quality of life.
Among the baseline predictors, self-efficacy was a key variable in the model for both patients and spouses. The longitudinal analyses illustrated the paths through which self-efficacy influenced outcomes. Less self-efficacy at baseline led to more negative appraisals of illness/caregiving, more hopelessness, and greater uncertainty for both patients and spouses at the 4 month follow-up and, as predicted by the theoretical model, some of these variables led to poorer quality of life outcomes at the 8 month follow-up. Because of its far-reaching effects on patient and spouse outcomes over time, self-efficacy should be included in patients’ and spouses’ clinical evaluations.
The number of current concerns reported by patients and spouses also was an important predictor in the model. Patients and spouses with more initial concerns had more negative appraisal of their illness and caregiving. A pile-up of concerns may occur (i.e., both illness- and nonillness-related) which overloads patients’ and spouses’ resources and leads to a more negative view of the illness or of caregiving. Note that higher baseline concerns had both a direct and indirect negative effect on spouses’ mental quality of life eight months later, but not on patient’s quality of life. Perhaps spouses with many baseline current concerns, who take on the caregiving role and assume roles that patients can no longer fulfill, deplete their resources and this negatively affects their long-term mental quality of life. Patients, on the other hand, appear able to reverse some of the effects of these early concerns as they proceed through the illness experience, by making better use of active coping, which leads to more positive long-term mental quality of life.
Interesting findings emerged for patient-spouse communication
. Spouses benefited from more communication with their husbands because it helped to reduce their uncertainty about the illness. In addition, patients who reported more communication with their spouses had less hopelessness. Researchers have found that supportive relationships help prostate cancer patients to cognitively process the cancer experience, which is associated with better mental health (44
). However, there may be a limit to how much patients benefit from communicating about the illness. We found a spouse partner effect that, when spouse-caregivers reported communicating more about the illness, the patients subsequently reported more hopelessness. While this finding warrants further investigation, it may suggest that some communication is helpful, but too much communication may prevent men from putting more of their attention on other matters in their day-to-day life. Another possible explanation is that not all communication about cancer is helpful. Helgeson and colleagues found that certain types of communication (e.g., urging patients to perform restorative health behaviors) led to poorer physical and mental health (45
). Therefore, it may be important to intervene with spouses to provide them skills and knowledge about the proper amount and type of communication strategies to use to best help patients cope with their illness.
The proposed model examined factors that promote the use of active and avoidant coping strategies
as well as the effect of these coping strategies on quality of life. Patients with more negative appraisal of illness used both active and avoidant coping strategies, with greater use of active coping leading to better mental quality of life while avoidant coping led to poorer mental quality of life, consistent with reports by others (9
). However, a different picture emerged for spouses. There were no direct paths to
active coping or from
active coping to quality of life for spouses (with the exception of one partner effect). In essence, active coping exists in isolation from the other variables in the model, suggesting that it was not a factor used by spouses to maintain or enhance their quality of life. For the most part, spouses used avoidant coping rather than active coping to manage their own symptom distress. While spouses may cope with their physical symptoms by denying or minimizing their own needs, our findings indicate that this has serious consequences for them and is associated with poorer mental quality of life, and also may lead to poorer physical health for spouses (46
). Furthermore, it should be noted that neither active nor avoidant coping related to physical quality of life. This relates to previous studies that showed that coping related to mental functioning and not physical functioning (23
). Despite the use of coping strategies, it may be difficult to change actual physical functioning. Coping strategies seem to relate more to how individuals emotionally deal with their physical health than their actual physical health.
The findings of this longitudinal study illustrated the mechanism through which antecedent, appraisal and coping variables affected quality of life outcomes in prostate cancer patients and their spouses. The analysis of this model supported many of the hypotheses derived from Lazarus’s Stress-Coping Theory: i.e., antecedent personal, resource, and illness variables, assessed at baseline, predicted appraisal variables 4 months later, which in turn led to secondary appraisal, evidenced by the use of coping strategies that affected quality of life at eight months. However, this theory does not explain all of the significant paths that emerged in testing this model. Rather it appears that the explanation of the mechanisms and outcomes are more complex than suggested by the basic model.
There are some limitations of this study that need to be considered. First, although the analysis was conducted with participants in the control group of a randomized control trial, the study may have had some effects on the responses of participants who were in the control group; they met with a nurse data collector who asked them questions about themselves. Furthermore, participants who agree to be part of a randomized control trial dealing with family involvement may not be generalizable to the population of prostate cancer patients. These results do not represent patients that do not have spouses or caregivers that are involved enough to agree to participation in an intervention. In addition, the relationship needs to be functioning enough to allow for recruitment into the study. Also, individuals who agree to be part of an intervention that allows nurses to visit their home regularly, may not be representative of prostate cancer patients as a whole. Second, the sample size was relatively small for an SEM analysis, though within the guidelines to yield stable parameter estimates (41
). Future studies using larger samples should replicate and expand this model by assessing additional complex relationships (e.g., whether factors such as stage of disease or baseline self-efficacy moderate model paths). Third, the small samples of participants in later phases of illness may have limited power to test the effects of illness phase on outcomes. Fourth, some findings may be related to being male or female rather than to being a patient or a spouse, and these could not be separated out in this study of male patients and primarily female spouses. Fifth, the selected mediators focus on only one aspect of appraisal (e.g., negative appraisal). There is less attention to positive appraisal (except active coping) variables that may also effect quality of life. Sixth, the sample was primarily white, wealthy, and well-educated. Therefore, it is important to assess whether the model fits well in lower or middle class settings. Furthermore, some of the associations may be different (e.g., the non-significant association of SES) among a more heterogeneous sample.
The results of this study suggest a number of implications that are clinically relevant to the healthcare providers of prostate cancer patients and their spouses. The study identified specific predictors of quality of life that are within the domain of healthcare providers to identify and intervene. For example, self-efficacy was shown to be a strong indirect predicator of both patient and spouse quality of life. Healthcare providers can screen individuals to identify those with low levels of self-confidence, and then provide or refer those individuals to appropriate interventions to increase their levels of self-efficacy. Furthermore, study results suggest that spouses need more help in using effective coping strategies when in their caregiving role.
Other quality of life predictors that are identifiable in the healthcare setting include age, phase of illness, general symptoms, and current concerns. Older spouses of prostate cancer patients, younger patients, patients with more symptom distress and current concerns, and patients experiencing biochemical recurrence or advanced disease are at greater risk for decreased quality of life. Armed with knowledge of these predictors, healthcare providers can assess these risk factors and intervene if needed, and thus assure that patients and their spouse-caregivers achieve their highest level of quality of life along their cancer trajectory.