In the current study, 70 % of participants who completed the survey (and 50 % of all eligible patients) were willing to answer a subset of questions about their life expectancy. Previous research into patients’ preferences for life expectancy information has yielded similar consent rates. A large USA-based interview study achieved a consent rate of approximately 70 % when assessing the views of 638 advanced cancer patients (recruited from outpatient clinics at seven hospital sites) about whether end of life care discussions had occurred [
18]. Australian survey research into cancer patients’ prognostic communication preferences have obtained consent rates of 61 % [
19]; while interview/focus group studies with palliative care patients have obtained consent rates of up to 83 % [
20]. However, recruitment for these studies was conducted through oncologists or palliative care services, and poor consent rates among oncologists or community nurses may have introduced response bias [
19].
Our findings indicating that older participants had lower odds than younger participants of answering questions about life expectancy appear to be consistent with past research. Kaplowitz and colleagues [
11] found that older people were significantly less likely to request and to be given prognosis information. Similarly, a review by Fujimori and colleagues reported that younger patients were more likely to express a desire for more prognosis information than older patients [
5]. Younger patients may be more likely to have dependent children and be willing to discuss life expectancy information for planning purposes [
21]. This may also reflect changes in patient attitudes, preferences, and expectations over time towards increased involvement in cancer treatment decision making [
22].
The increased willingness to answer questions on life expectancy among males was contrary to our expectations. It has been reported that women diagnosed with cancer are more likely to want more detailed general information about cancer than men [
10]. A study of response rates to an epidemiological survey involving 25,000 participants found that consent to review medical records higher in males older than 50 than females over 50 [
23]. Other research has found that men were significantly more likely to be given a quantitative life expectancy estimate than women [
11]. Taken together, these findings may suggest that males are more likely to be willing to be involved in research about personal or potentially sensitive issues than females.
Our findings showed that Australian-born participants had higher odds of completing life expectancy questions than respondents born in the Asian region, and marginally non-significantly higher odds than those born in Europe. Previous reports have indicated that culture may influence patients’ preferences for information about life expectancy prognosis discussions [
5]. A recent review of patients’ preferences for life expectancy communication reported that studies conducted in Asian countries have reported that fewer than 30 % of patients wish to know about life expectancy, while approximately 60 % of Westerners do [
4,
5]. Regional variations in physician views and practices surrounding disclosure of palliative illness status in Europe, Latin America, and Canada have also been reported [
24]. These differences may be related to beliefs about the potential impact that awareness of a poor life expectancy estimate may have on patient hope, and consequentially on outcomes. Therefore, the present findings may be reflective of cultural attitudes towards discussion of life expectancy. However, a recent qualitative study looking at communication preferences in migrants to Australia with Greek-, Arabic-, and Chinese-speaking backgrounds, suggests that these migrant groups are possibly more likely than Anglo Australian patients to prefer to have access to prognostic information [
25]. It may be that a willingness to answer questions about life expectancy is not comparable to a patient preference to have access to prognostic information. It is also possible that responses regarding willingness to answer life expectancy questions in the current study may have been influenced by family members who may have been accompanying them in the waiting room during survey completion. Further exploration of discordance between patient and family preferences may be warranted in Australian and international settings. However, it does seems likely that some level of cultural variation in patient preferences for answering life expectancy questions exists and further exploration of how this relates to patients preferences for life expectancy disclosure may be warranted. This is particularly pertinent given that individuals without adequate English language to complete the survey were excluded from this study. Future studies should extend these findings to culturally and linguistically diverse communities [
25].
Prior research has indicated that patients who identified themselves as having a shorter survival time may be less likely to want, request, and receive life expectancy information compared to those perceiving longer survival time [
11]. It has also been suggested that an increased physical burden of cancer may be associated with a preference to have less involvement in cancer care decision making [
10]. The current study found no association between patients’ perceived treatment aim and willingness to answer the life expectancy questions. However, individuals in the present study diagnosed with cancers with high 5-year survival rates (i.e., breast or prostate) [
1] were more willing than those with other cancers to complete life expectancy questions. It is possible that the greater willingness among breast and prostate cancer patients was linked to perceived length of life. This would appear consistent with the findings of Kaplowitz and colleagues [
11]. For instance, increased rates of distress in some poorer prognosis cancer types such as of the lung and brain have been suggested to be associated with feelings of “doom” [
26]. This finding warrants further exploration, as the preferences of patients with less common cancers tend to be under reported in current consensus guidelines.
Limitations
This research compared the characteristics of survey participants who were and were not willing to answer a subset of questions about their life expectancy. However, as part of the consent process potential participants were made aware of the optional section about life expectancy, and potential respondents (for whom demographic information is not available) may have opted out at this point. Additionally, although the current study achieved high consent rates to the initial survey (87 %), only 70 % of all eligible patients completed the entire survey in the time available. Once again, demographic information is not available for participants with incomplete surveys, meaning comparisons between survey completers and non-completers are not possible. Given that 70 % of eligible participants completed the survey in its entirety and 70 % of these respondents were willing to answer questions about their life expectancy, overall, 50 % of all eligible participants completed the life expectancy questions. Although this overall consent rate is comparable to other research [
27], it may limit the external validity of the study results.
All patient demographic and disease data was collected via patient self-report, meaning accuracy for some items may be questioned [
28]. Accuracy of self-reported cancer history validated against medical records and cancer registry data has been found to be high [
29], with high sensitivity in cancer outpatient samples [
30].
Implications
There remains a need for high-quality research in the area of life expectancy communication. However, this research needs to minimize the risk of psychological distress to patients while also maximizing the representativeness of samples consulted. This approach to empowering patients to decide whether or not to answer research questions of this nature, rather than having access to patients restricted by clinical gatekeepers, requires a balancing of the ethical principles of beneficence and autonomy [
31]. The current study found high consent rates to both the initial survey and also to the life expectancy questions embedded within the main survey, which resulted, in an overall acceptable consent rate. This suggests that this patient-centered approach to researching this sensitive topic was both feasible and acceptable, but the degree of acceptability varied across different subgroups. Further research may be needed to identify how to improve acceptability of this research to subgroups including those who are female, aged 60 years or over, diagnosed with less common cancer types, and Australian migrants from Asian regions [
5,
22].