While the impact of urologic cancer on health-related QoL has been examined in multiple studies, the aim of the work presented here was to test whether other QoL domains are also affected by the disease and whether the subjective importance ratings of various QoL dimensions differ between urologic cancer patients and the general population. Health is one of several QoL dimensions included in our analyses; this allows us to investigate the relevance of health in relation to other areas of QoL.
The most relevant QoL dimensions were health and family life, each of which had mean importance scores above 4 on a scale of 1-5. However, the general population also considers health to be the most important dimension; there were no significant differences in the health importance assessments between the patients and the general population. Other general population studies have also reported health receiving the highest importance ratings [19, 31]. While the patients’ mean importance ratings were higher than those of the general population in four of the seven other dimensions, the other three dimensions showed an opposite trend. This means that the non-health domains do not become less relevant for people after they have been diagnosed with cancer. As such, it is important to consider problems concerning finances, work, and social relationships when studying patient QoL, as these less physical aspects of life appear to be highly relevant for patients as well [32].
Concerning satisfaction, it is not surprising that the most relevant difference between the patients and the general population was found for the health domain. Nevertheless, the patients’ mean satisfaction rating was 3.08 which is nearly exactly the middle of the 1-5 scale, rather than in the lower half of the scale as one might expect. The patients’ satisfaction ratings were higher than those of the general populations in all of the other domains, and in five of the seven cases even with statistically significant differences. This could be a result of a judgment effect: when there are severe detriments in one area (health in this case), the problems in other areas seem to become less relevant. To gain a better understanding of a person’s satisfaction with their health state, it might be useful to consider not only their satisfaction with their health alone but also with their health in relation to their general satisfaction with other areas as well.
During the 3-month period between t1 and t2, satisfaction scores slightly improved in the health domain (effect size d = 0.17), but became worse in the partnership domain, with a large effect size of d = -0.41. The item includes both partnership and sexuality. While in most cases the combination of partnership and sexuality in one dimension makes sense, for prostate cancer patients, these sub-domains can be experienced quite differently. Several patients reported for example that they were highly satisfied with their partnership but very dissatisfied with their sexuality. Since urologic cancer patients often experience urinary and sexual symptoms that do not disappear within the first months after surgery [12, 15, 33, 34] the loss in satisfaction with the combined partnership/sexuality dimension is understandable. Partnership and sexuality are areas of life that deserve special attention in the treatment of urologic cancer patients and survivorship care plans [15, 35–38]. A US-American study showed poorer quality of sexual communication and more sexual dissatisfaction after treatment in patients than in the general population [39]. Moreover, patients´ relationship satisfaction, quality of communication about sexuality, and sexual satisfaction were strongly associated with their partner’s satisfaction with the overall treatment outcome [15] and partners´ level of depression and sexual activity [39].
When considering the changes in QoL scores from t1 to t2, one must take into account that they might have been affected by response shift processes whereby the respondents’ frames of reference changed due to adaptation processes [40–42]. A study with prostate cancer patients [41] tried to quantify this effect and to estimate “true” changes. So-called thentests [43] could be used to further explain such effects and to better understand the real changes.
How do the eight QoL dimensions contribute to global QoL scores at t2? The results of the regression analyses (Model 1) show that all of the dimensions positively contribute to this global score, and that the only non-significant dimension is partnership. The highest contributions came from the dimensions health (beta = 0.418) and income (beta = 0.386). Even after including the baseline value in the regression analyses (model 2), the domains with the highest beta values were health (beta = 0.323) and income (beta = 0.311). A general population study [22] found that income was the strongest predictor of general life satisfaction (r = .59), while health was a weaker predictor (r = .46) and comparable with the dimensions friends (r = .45) and job (r = .47). It would be interesting to compare the associations between health satisfaction and general life satisfaction between patients and the general population in a more systematic way. Our analyses were controlled for age, education, and tumor stage. Therefore, these factors cannot be considered confounders for the effects. The relevance of the domain income seems to contradict the low importance ratings of this domain. While the patients declare that income is not so relevant for them, those patients who are satisfied with their income report a higher overall QoL than those who are less satisfied with their income. There is no linear relationship between the direct, explicit importance ratings of the dimensions and the indirect assessments based on associations with global QoL. While both analytical approaches reveal the health dimension to be highly relevant, the income dimension shows that the results of these two approaches may differ considerably. A similar phenomenon was observed in a general population study [22] where the domains with highest mean importance ratings were not necessarily those with the highest capability for predicting global life satisfaction. This shows that direct assessments of subjective importance must be considered with caution.
Some limitations of this study should be mentioned. While multiple studies have investigated health-related QoL in urologic cancer patients, assessments of QoL areas beyond health are rare, and considering the subjective importance of other life domains is a relatively new pursuit. Therefore, we could not compare our main findings with results obtained in the scientific literature. The dimension partnership/sexuality included two components which, in the case of urological cancer patients, do not form a consistent scale. We showed that direct importance assessments and indirect assessments in terms of beta coefficients can result in different outcomes. While health was relevant in both approaches, the income dimension showed contradictory results. We cannot derive conclusions about the best way to infer the subjective relevance; a more stringent comparison between these direct and indirect methods would be a task for future research. Though the response rate of this study was relatively good, it is possible that the proportion of patients with severe problems is underrepresented since the t2 sample included only those study participants who had survived until at least three months after t1 and who were willing and able to take part in the t2 assessment. Though we tried to select a control group with a similar distribution of age and education, there may be differences with regard to other aspects such as income we could not control for. We addressed several research questions in this paper, but the data set can also be used for testing other relationships, e.g., the correlations between the importance and the satisfaction ratings, or testing the “domain-importance-as-a-leveler-hypothesis” [31] that postulates a moderating effect of the domain importance on the associations between domain satisfaction and global QoL, or the associations between changes in importance (from t1 to t2) and changes in satisfaction.
In summary, the results of this study underline that health is a relevant dimension of QoL but not solely so. The importance of the domain income/finances shows that this aspect is also meaningful for understanding cancer patients’ life situation, even if they do not explicitly state that to be the case. The domain partnership/sexuality is especially sensitive for urologic cancer patients and should be taken into account in the cancer care setting. Domain importance is meaningful. Even if importance ratings are not necessary for qualifying a weighted global QoL score, they are useful tools for better understanding what is truly relevant for patients [44].