Bereaved Family Caregivers Perception of Trust in Palliative Care Doctors by Patients with Terminal Cancer

Abstract Trust is a key factor in achieving a good death. However, few studies have focused on factors that help patients with terminal cancer establish trusting relationships with their palliative care doctors. This exploratory qualitative study, conducted in Japan, was designed to identify factors related to terminal cancer patients’ trust in their doctors. Semi-structured interviews were conducted with 18 caregivers and grounded theory was the research approach chosen to guide this study. The data revealed seven factors related to the trust to palliative care doctors, including caring attitude, symptom management, courteous and specific explanations, long-term involvement in the patient’s care, being faced with inevitable death, good impression of the institution, and referral by a trusted doctor. These factors were categorized into three main themes: [1] palliative care doctors, [2] patients with terminal cancer, and [3] professional reputation. There is potential for improving end-of-life experiences through understanding and implementing interventions to ensure trust identified by these caregivers


Introduction
Achieving a good death is primary goal in palliative care.The concept of a "good death" varies across cultures and healthcare systems, resulting in a complex and multifaceted definition.In Japan, "good death" is considered important to alleviate physical suffering and enable patients to make decisions about how they want to experience their final moments.(Miyashita, Sanjo, Morita, Hirai, & Uchitomi, 2007;Morita et al., 2015) Previous studies reported that trust to doctors is a key factor in achieving a good death (Hamano et al., 2017;Kanda, Takashima, Tsuji, Yokoyama, & Hirao, 2019;Kastbom et al., 2016).However, few studies have clarified the factors that generate trusting relationships between patients with terminal cancer and palliative care doctors.
Definitions and concepts of trust have been studied in both the medical and the social fields."Trust" is broadly defined as a state of expecting certain behaviors and intentions from others (Kim, Bae, Kang, Kim, & Lee, 2018;Mayer, Schoorman, & Davis, 1995;M€ ollering, 2001).In doctorpatient relationships, patients expect doctors to give them an appropriate diagnosis and treatment.The fulfillment of this expectation leads to trust.In addition, Hall and colleagues reported that trust is inseparable from the vulnerability created by illness and invasive treatment (Hall, Dugan, Zheng, & Mishra, 2001).Previous studies found that trust in medicine is generated by these expectations and vulnerabilities (Hall et al., 2001;Kim et al., 2018;Mayer et al., 1995;M€ ollering, 2001).These studies show that trust may have qualitatively different forms.
Several doctor-related factors found to be associated with trust in the doctor-patient relationship include background factors such as age, gender, country of training, years of experience, and institution of practice, as well as personal attributes such as attitude, competence, patient-centered communication, honesty, sincerity, altruistic behaviors, insusceptibility to medical errors, and being a family physician or relative.Other studies linked trust with interpersonal factors such as providing full explanations of care, doctor-patient relationship length, visit/appointment length, and hygienic appearance, and social factors such as appearances in mainstream media, a good reputation, a recommendation from the patient's family, and the doctor's status in the medical community (Croker et al., 2013;Fiscella et al., 2004;Hall, Camacho, Dugan, & Balkrishnan, 2002;Nishigaki, Asai, Ohnishiki, & Fukui, 2004;Pearson & Raeke, 2000;Shaya et al., 2019).
Nishigaki et al. (Nishigaki et al., 2004, pp.12) found that Japan's universal health insurance system, which grants patients autonomy in choosing hospitals, except in emergencies, is positively associated with high levels of trust in the Japanese healthcare system.In Japan's palliative care services, patients with cancer initially receive diagnosis from different medical departments.If they show declining functioning or severe symptoms, they are referred to the palliative care department, usually through referrals from other departments.Within the framework of palliative care, personalized information about prognosis, symptom management options, and future care arrangements is provided based on the patient's condition.Decisions regarding palliative care are ideally collaboratively made through consultation with the patient and their family.Given the flow of palliative care and the awareness of limited time among patients with end-stage cancer, the factors influencing trust between patients and palliative care doctors may differ from other medical contexts.
Hillen studied trusting relationships between oncologists and patients with cancer (Hillen, de Haes, & Smets, 2011, Hillen, Onderwater, van Zwieten, de Haes, & Smets, 2012), but did not focus on palliative care doctors or patients who are near death.Indeed, few studies have focused on this subset of doctors and patients.Patients at the end of life are different from other patients in that they recognize that their death is near.They gradually weaken, and curative treatment is not an option.These differences might lead to different factors being associated with trust in the doctor-patient relationship.Therefore, research focusing on palliative care doctors and patients is needed.Furthermore, clarifying the crucial factors in these relationships may help to facilitate the construction of good relationships, and this may contribute to the patient's ability to achieve a good death.In this study, bereaved family members of patients with cancer were interviewed to explore their perceptions of factors that contributed to patient trust in doctors.

Study design
This qualitative study was conducted in Japan between November 12, 2019, and September 30, 2020, using the Grounded Theory Approach (GTA) to explore the factors associated with trust in palliative care doctors among patients in the end-of-life stage and to develop a theoretical framework.(Saiki, 2014).

Setting and study period
This qualitative study was conducted in Japan to clarify factors related to patients' trust in the palliative care doctor between November 2019 and September 2020.

Participants
Family members of patients with cancer who died in Jichi Medical University Hospital's palliative care unit between January 1, 2013 and September 30, 2018 were recruited as participants.The family members are defined as "those closest to the patient and who care for them intimately" in this study.It includes biological family and others.participants diagnosed with dementia and youths under 20 years old were excluded.The initial participant for the interview was selected by purposive sampling from 71 bereaved family members.The reason for employing purposive sampling was to facilitate initial theory development.For subsequent participants, the theoretical sampling approach was utilized to extend theory and to enhance the robustness of the emerging theory.Participants in this study were interviewed between one to five years after the patient's death.

Data collection and interview contents
Data were collected in semi-structured interviews by the first author who had not participated in the treatment of the patient and never met the participants.All interviews were conducted by the first author and recorded using an electronic audio-recording device.Before starting each individual interview, the following information was collected from the patient's medical records: age, gender, history of terminal illness, period of hospitalization, we also recorded the participant's age, gender, and relationship to the patient.The interviews were largely conducted according to the script in the interview guide, which was composed of four parts: (1) the patient's relationship with their palliative care doctor; (2) reasons the participant trusted (or distrusted) the doctor; (3) reasons the patient had trusted (or distrusted) the doctor; and (4) the degree of trust placed in the doctor (on a scale of 0-10) personally and by the patient.Below are examples of questions included in the interview guide: "In your view, how much did your relative trust the doctor?Please answer on a scale of zero to ten." or "Why did/didn't your relative trust the doctor?"Additionally, clarifying questions were asked if unclear points remained.In order to minimize participants' bias (the reasons why participants trust doctors) on the study outcomes, data on two dimensions were collected: reasons why the participants trusted (or distrusted) the doctor and reasons why the patients trusted (or distrusted) the doctor.Before the analysis, the dimension related to the reasons participants trusted (or distrusted) doctors was excluded, and exclusively the "factors for patient trust in doctors" were extracted and a GTA analysis was conducted.
In accordance with the research protocol, semi-structured interviews lasting approximately 40 minutes each were planned for participants who had experienced the loss of a family member.This time allocation aimed to mitigate potential psychological distress associated with extended interview sessions.The specificity of our research theme, which revolves around "the factors influencing patient trust in palliative care physicians," led us to conclude that gathering the necessary data within a 40-minute interview time frame was adequate.To enhance the efficiency of data collection during this period, data was proactively gathered, including basic information about the patients and their family members and interviews conducted following an interview guide.Regarding data reliability, the use of the interview guide during interviews with each participant suggests minimal variation in the obtained information.Additionally, the use of electronic audio-recording devices allowed for accurate verbatim transcripts, which were subsequently reviewed by three researchers to maintain content integrity and minimize data distortion.In this study, a total of 18 participants were recruited; the mean interview time was 34 minutes (Table 1).

Data analysis
GTA was conducted by three investigators to explore the factors related to the trust in palliative care doctors by patients with terminal cancer.After conducting the interview with the initial participant, the interview audiorecordings were transcribed verbatim.Analysis was then performed on these transcripts to extract factors related to the patients' trust of their doctor.This process was repeated for subsequent participants, with each analysis conducted separately, in succession and compared as we went forward.Any new factors identified were added to the construct.These steps were repeated until no new factors could be extracted (i.e., until theoretical information saturation was achieved), at which point the recruitment and interviews were stopped.Furthermore, during the analysis process, two qualitatively different forms of trust emerged.Therefore, factors related to these distinct forms of trust were analyzed.The categorization of these different qualitative dimensions of trust was conducted based on the verbatim accounts provided by participants (e.g., in English, have to trust or we have no choice and so on)."The trust" was divided into two categories: "expectation-based trust" (positive trust) and "need-based trust" (negative trust).

Ethics approval
This study was approved by the institutional review board of Jichi Medical University.Informed consent was obtained from all participants before their participation in the study began.

Results
The seven factors identified as related to patients' trust were: caring attitude; symptom management; courteous and specific explanations; long-term involvement in the patient's care, (i.e., by the palliative care doctor); being faced with inevitable death; good impression of the institution; and referral by a trusted doctor.On these factors, courteous and specific explanations and being faced with inevitable death were the most discussed: 10 out of 18.A theoretical framework was constructed to describe the relationship of these seven factors to the patients' trust, (Figure 1) and seven factors were categorized under three main themes: [1] Palliative care doctors, [2] Patients with terminal cancer, and [3] Professional reputation (Figure 2).

Palliative care doctors
This first theme included four factors: caring attitude, symptom management, courteous and specific explanations, and long-term involvement in patient's care.

Caring attitude
Compassion.The participants said that doctors who displayed a compassionate attitude toward patients not only help in building trusting relationships but also have an impact on the treatment.
"The palliative care doctor was compassionate [to the patient].He treats his patients like his family and respects their lives on an individual basis."(59 yr old wife) In this context, compassion refers to doctors treating patients like their own family.Another participant expressed Compassion as doctors putting themselves in the patients' shoes.with respect and promptly providing medical care when patients' conditions worsen.
The doctor treated him earnestly and respected him.So, he trusted him.When he suddenly felt sick (while staying at home), the doctor would see him immediately in the outpatient clinic.When making an appointment, the doctor would tell him to come at 3 pm, things like that.He took comfort in the fact that he could be seen quickly in urgent situations.(82 yr old, older sister)

Communication
The participants reported that communication relieved the patients' anxiety.Patients confessed things to their doctors that they could not confess to their family, such as the pain of their symptoms and the difficulty of their treatment, and felt relief when their doctors listened to them.
"She listened to the doctor's explanations carefully, which took a load off her mind.So, she apparently trusted the doctor."(52 yr old husband) The doctors might have relieved the patients' mental burdens, either by easing their anxieties through their words or by sharing the difficulties of demanding situations and ongoing treatment.This could have resulted in a feeling of relief."Through conversations with the doctor, he expressed his negative emotions.He would tell the doctor things he couldn't tell his family [when he was undergoing] outpatient care, such as [describing] his tough situation and the pain of undergoing treatment."(62 yr old wife) Furthermore, the doctors sometimes told jokes to relax the patients and lighten the mood, which facilitated conversations.
I might rate his degree of trust as 10 [out of 10].He told me, "The doctor and I have a relationship where we are able to joke with each other."When I heard that, I thought the doctor made jokes to relax him.(31 yr old daughter.) Symptom management.The participants reported that good symptom management by the palliative care doctor was related to the formation of trusting relationships.
"Usually, he rarely complained, but he said, 'I can't stand the pain anymore.'He trusted the doctor because the doctor used opioids to alleviate his dull pain."(68 yr old wife) Symptom management involves not only alleviating discomfort, but also implementing treatments that patients desire.
The patient's reluctance to undergo gastric tube insertion was met with understanding and acceptance by the palliative care physician, who offered alternative options.This provided the patient with a significant sense of reassurance.My dad's hope was that his distress (Abdominal bloating) would be relieved, which matches the direction of palliative care.That's why he trusted the doctor.(31 yr old daughter) In some cases, symptom management does not directly impact trust levels.Despite experiencing only moderate symptom relief, certain patients exhibit a high level of trust in their palliative care physician.
"Well, toward the end, you know, the breathing was difficult, so there was a sense of suffering.The pain and suffering were a little relieved, though … (Trust in the palliative care physician was 100%)" (67 yr old husband) Courteous and specific explanations.This factor is most discussed in this study as well as Being faced with inevitable death.The participants indicated that courteous and specific explanations were related to the formation of trusting relationships because they alleviated anxiety.The topics explained by the doctors included palliative care policies, the patient's condition, life expectancy, hospice location, opioid medications, and symptoms that were predicted to appear close to death.
"The doctor explained everything from A to Z, that's why she trusted him.She wanted to be back home, so she would ask the doctor about what she didn't understand and the possibility of returning home."(52 yr old husband) The participants also indicated that truthful estimates of the patients' life expectancy directly earned the patients' trust.
"The doctor faithfully explained how long he would live, which was based on evidence.Such honest explanations, not mincing words, were what made him trust the doctor."(66 yr old wife)

Long-term involvement in the patient's care
Length of care.Length of care was related to trust formation.The participant explained that there were more opportunities for the patients to interact with palliative care doctors the longer they were cared for.
"The longer he was cared for, the more he and the doctor talked together; [that's why] he trusted the doctor."(68 yr old wife) Reinforcing this statement was heard from other participants as well.Participants stated that It is unclear whether he had trusted the doctor or not due to the short duration of care and limited conversations.
He trusted Dr. A, the oncologist who treated my husband on a long-term basis.But he only met a palliative care doctor on the day he was hospitalized, and had no connection with the doctor after that.So, I have no idea whether he trusted the palliative care doctor.(74yr old wife) While some felt the length of time was important, others felt that the content of the conversations was more important to building trust than time per se.
"I get the sense that it's not the number of days [a patient is cared for that fosters trust], it must be the content of the conversations.Patients feel calmer based on how much doctors tell them."(58 yr old, older sister) Familiar doctor.One participant revealed that her mother's experience tending to a relative in the same palliative care unit had fostered a trusting relationship with the palliative care doctor there when she was admitted to the ward herself.
"My wife already knew Dr. B as the palliative care doctor who was in charge of her mother-in-law's care previously.She often said that he was familiar with medication, and particular about the details of prescriptions."(66 yr old husband)

Patients with terminal cancer
This second theme included a single factor-being faced with inevitable death-which consisted of three components: physical disability, incurable disease, and recognition of one's life expectancy.

Being faced with inevitable death
Physical disability.The participants reported that the patients had no choice but to trust their doctors, because of their gradual weakening due to their terminal cancer.Physical disability in this context means that patients were unable to talk or take care of personal matters independently.
"Before he passed away, he had no voice and couldn't move the way he wanted.So, he had to rely on … [and] trust the doctor; I think that's why it was tough for him."(66 yr old husband) Incurable disease.Participants stated that he had nothing else to depend on besides palliative care, and thus, he trusted the doctor for that reason.The quality of this trust may differ from conventional trust.
"There were no treatments that could cure him.So, he had nothing to depend on, except palliative care.That's why he trusted the doctor."(59 yr old wife) The participants reported that the patients had undergone various treatments such as chemotherapy, radiation, and surgery before they were hospitalized in the palliative care unit.They had therefore recognized that their illness was incurable and that they had no further treatment options except palliative care; therefore, they had to trust the doctor.
She left it to the doctor; it couldn't be helped.She'd undergone various treatments for two and a half years, she understood this.Then, an oncologist told her, "If this anticancer drug is ineffective, there is no effective medicine."So, she knew there was no possibility of her illness being cured.(69yr old husband) Recognition of life expectancy.Recognizing their limited life expectancy led to the patients' placing their trust in their doctors.
My wife said she was helpless, that her fate was out of her control.I guess it was in the doctor's hands.When she moved from gynecology to the palliative care unit, she recognized that her life expectancy was limited.So, she trusted the doctor completely.(67yr old husband) While some participants used language such as "the doctor's hands" or being "helpless," others said that the patients wanted to live out their remaining days to the fullest extent and trusted their doctors' advice on how to die well.
"They were his last moments.I think he might trust a doctor.He would like to go to his final glory."(69 yr old husband) Participants expressed the process of approaching death as "his final glory."Additionally, other participants expressed a desire to trust the doctor and spend their last days, which could be related to the degree of acceptance toward death.
I think it's more about her recognizing that her own life is nearing its end, rather than finding comfort in listening to the doctor's words.She had that awareness and was prepared for it herself.It seems to me she wanted to live out her last days by doing as the doctor said.The only medications she could take were painkillers; she couldn't eat or drink anything.She wanted to live her last days by trusting the doctor.(66yr old husband)

Professional reputation
This third theme included two factors: good impression of the institution and referral by a trusted doctor.
Good impression of the institution.A good impression of the institution of care mattered.Aspects included being a well-equipped institution, being engaged in cancer research, and brand image.
My wife favored the hospital.She said it is the best institution in our region.The doctors belonging to the hospital have good medical skills and explain things well.That's why my wife trusted the hospital, I think.She was also affected by the following two factors: the hospital being a well-equipped institution and the brand image of the hospital.Those factors led to her trust.(66yr old husband) The participants reported that a positive impression of the institution led to trust in the institution, and furthermore, that patients' positive evaluations of the institution promoted trust in the doctors affiliated with it.This is believed to be related to the notion that good facilities are likely to have competent doctors, or that there is a strong likelihood of receiving guidance from skilled physicians.
"The hospital has conducted a lot of oncological surveys.It appeared in some newspapers.So, since it has a famous oncologist, other doctors in the hospital would be trained by him.That's why she trusted the hospital."(69 yr old husband) Referral by a trusted doctor.According to the participants' explanations, the patients tended to recognize that they would receive the best medical care by being referred to another department.
"The oncologist referred her to palliative care, and she thought the doctor would provide her with the best treatment.(So, she trusted the palliative care physician.)"(67 yr old husband) Some of the participants reported that the patients had already built a trusting relationship with their former doctor, which carried over to their relationship with their palliative care doctor.
"My husband trusted the palliative care doctor because he was referred by a previous doctor whom my husband trusted and who knew his condition in detail.The opinion of the previous doctor had a large influence on us." (74 yr old wife)

Factors not related to trust
All the participants stated that trust was unrelated to the sex, age, job title, or institution of training of the palliative care doctor.Although a few participants stated that their relatives had previously experienced events that left them with a distrust of medicine, this did not affect their trust in their palliative care doctor.
"Cleanliness is important, but factors like age or the doctor's alma mater are irrelevant to patients and their families.We focus on proper explanations when interacting with patients."(52 yr old husband) Participants explained that the personal information of the doctors was not related to trust, and that their interactions with the patients were what mattered in terms of building trust.
[Positions, training, gender, or age] It's not important.What matters is how they engage with patients.It's about treating patients equally, not asserting superiority as a doctor.If a patient express concerns or asks questions, the doctor should respond honestly and explain the situation.(69yr old husband)

Nested structure of trust
During the interviews exploring trust in palliative care doctors, discussions extended to nurses, clinical psychologists, pharmacists, and others, indicating trust in the entire palliative care team.Therefore, it cannot be ruled out that trust in the palliative care team may also influence trust in the palliative care doctor.Similar to how trust in the healthcare institution is related to trust in the physician, trust may be influenced by the physician's affiliation and the collective impact of the treatment team.
"He wanted to rest without pain, anxiety, or distress.The palliative care team made him comfortable and eliminated his pain.That's why he trusted the doctor [and team]."(62 yr old wife) The palliative care team encompasses diverse professions.One participant highlighted their trust in pharmacists, clinical psychologists, and other team members, stating that this trust extended to their confidence in the palliative care doctor.
It's not just about trusting palliative care, right?It started with pharmacist Y from the clinical oncology department, and the oncologist was also kind and trustworthy, and the psychologist listened well, which is why I trusted them.Similar to the trust in the pharmacist and psychologist, I also trusted the palliative care physician.(66 yr old wife) Another participant expressed trust in nurses.The reasons for trusting nurses were related to their respectful and sincere answers for patients "He trusted the physician and the nurse.The palliative care staff took very good care of him.It was truly wonderful.They always gave sincere answers, and the nurses handled things with integrity, and they did a great job."(82 yr old, older sister)

Degree of trust of the patients and family
According to the participants, the degree of trust placed in their palliative care doctor by the patients, on a scale of 0-10, was 9.1 ± 1.4 (n ¼ 16; two cases claimed not to know their relative's opinions on the matter).In comparison, the participants reported their own degree of trust in the same doctor as 9.1 ± 1.5 (n ¼ 18).

Factors important in the experience of trust
One of the objectives of this research was to explore the factors related to the trust patients with terminal cancer in palliative care doctors.Two factors identified here have not been reported in previous research, making them unique to palliative care: symptom management and referral by a trusted doctor.Symptom management is one element a patient expects from a palliative care doctor.Modes et al. indicate that the most common reason patients undergo treatment is for symptom management (Modes et al.,2020).In this study, the participants reported that the patients hoped to have their pain, malaise, and other symptoms relieved, indicating that symptomatic relief is related to patients' trust.Miyashita and colleagues reported that dying well requires alleviation of the patient' s symptoms (Miyashita et al., 2007).Therefore, patients with terminal cancer trust a palliative care doctor to help them achieve a good death.
Nishigaki (Nishigaki et al., 2004, pp.12) reported that trust levels increase when patients have autonomy to choose hospitals and departments under the national health insurance system.Despite the frequent referrals and limited direct visits common in palliative care, this study observed high levels of trust.This suggests that referral by a trusted doctor may contribute to these results, even if patients do not personally select their hospital.While this study identified seven factors, it is important to consider the specific context of Japan, as different factors may be relevant in other countries.Additionally, Macy (Macy & Sato, 2002) noted that collectivist Japanese exhibit lower trust in unfamiliar individuals compared to individualistic Americans, indicating the potential for different trust-related outcomes.In future, more research is needed to assess the validity of the factors identified here and to clarify whether these factors encourage patients with terminal cancer to establish and build trusting relationships with their palliative care doctors and potentially contribute to achieving a good death as a result.

Two qualitatively different forms of trust
As illustrated in Figure 2, two types of trust were observed based on the participants' remarks and could be classified as "positive" and "negative," according to motivation.Some of the participants explained that the patients wanted to spend their remaining days resting without distress and this is why they trusted their palliative care doctors.This trust-which we called "expectation-based trust"-was directly linked to their expectations of dying peacefully and painlessly, indicating similar qualities to the definition used by scholars such as M€ ollering: "a state of favorable expectation regarding other people's actions and intentions (M€ ollering, 2001, pp. 404)."On the other hand, some participants expressed the concepts "having no choice but to trust" and "leaving things in the doctor's hands."It is called trust based on such feelings "need-based trust," which is similar to "the need to trust" reported by Hillen (Hillen et al., 2012).He identified lifethreatening illness and the acute phase of illness as factors leading to this need to trust, this research clarified that physical disability (5-1), incurable disease (5-2), and recognition of limited life expectancy (5-3) are underlying need-based trust in patients with terminal cancer (see figure; the numbers refer to direction of factors).These three factors have not been reported in past research on patients' trust in their doctors, and yet are unique characteristics of patients at the end-of-life.The trust patients with terminal cancer consists of expectations of palliative care doctors and the need to trust.Expectations of palliative care doctors are related to all seven factors identified here, whereas need-based trust is related to the fifth factor only: being faced with inevitable death.However, when approaching death, some patients opt willingly to trust their doctors to provide a peaceful death, while others are forced to trust their doctors by their situation.Therefore, recognizing the reality of imminent death does not necessarily lead to need-based trust.This will greatly contribute to future research on a good death.

Nested structure of trust
In the "Nested Structure of Trust" section of the results, the content of participants' interviews revealed that trust in palliative care doctors exhibits a nested structure, wherein the confidence placed in healthcare institutions and the palliative care team holds the potential to influence trust in palliative care doctors.This entire palliative care team is anticipated to encompass not only nurses, pharmacists, and psychologists, but also social workers.Therefore, it is plausible to consider that a patient's trust in a physician may not be solely contingent upon the individual attributes, capabilities, or affiliations of that physician alone; rather, it might be inadvertently influenced by other health professionals.

Implications for health professionals' practice
In this study, it was reported that patients associate trust not only with physicians but also with nurses and other healthcare professionals who exhibit a respectful attitude and provide sincere responses.Therefore, a respectful attitude and sincere responses by all medical professionals are essential for building trust.While the participants were family members of inpatients receiving palliative care, the role of social workers becomes particularly crucial in home palliative care.Therefore, in home palliative care settings, social workers may form trust relationships with patients that contribute to trust in the palliative care team and doctors, as a result impacting the potential for patients to achieve a "good death."

Limitations
This study has several limitations.It was conducted at a single facility, so it may not have captured the full range of variation in the population.GTA was conducted based on patient comments regarding trust in palliative care doctors.However, it was difficult to completely eliminate the influence of participants' trust in the palliative care doctors, as well as their trust in the healthcare institution and the palliative care team, on their trust in the specific palliative care doctors involved.Since this study was conducted after the patients had died, the interviewees' satisfaction or trust in providers with the care provided may have affected these findings.In order to examine whether factors related to trust identified in previous research articles would have similar results in this study, this interview guide also included closed questions.but these questions may bias results in this research.Moreover, this study was conducted one to five years after the patient's death, which raises the possibility of recall bias due to memory degradation.With the purpose of recalling that time, participants were asked about the patient's trust experience after introducing the relative's care history in the questions.This could have been a leading question.

Conclusion
This research has identified seven factors associated with patients' trust in palliative care doctors, revealing two distinct qualities of trust."Expectation-based trust" arises from the anticipation of a peaceful and painless death, while "need-based trust" stems from acceptance due to limited life expectancy and incurable illness.Moreover, the trust in palliative care doctors was found to be influenced by the affiliations of both the healthcare institution and the palliative care team.These findings may impact the establishment of trust between patients with terminal cancer and palliative care doctors, and they contribute to achieving a "Good death." "I think compassion is related to trust … I mean, it is important for doctors to walk in patients' shoes.It affects their treatment.If patients close their minds, treatment doesn't go well."(62 yr old wife) It appears that compassion can also be perceived through physicians' responses.Participants described attitudes related to compassion as treating patients

Figure 1 .
Figure 1.Solid arrows indicate the relationships of the seven factors identified in this study with the two types of trust (i.e., expectation-and need-based trust).Dashed arrows indicate interactions between categories.Relationship properties are denoted by bold font; dimensions are preceded by a colon (:).

Figure 2 .
Figure 2. Expectation-based trust (red) and need-based trust (blue) are shown.Factors [1] palliative care doctors (green) and [3] Professional reputation (yellow) belong to expectation-based trust.Meanwhile, [2] patients with terminal cancer (orange) is associated with both expectation-based trust and need-based trust.

Table 1 .
Each participant represented one patient, and the group of patients comprised eight males and ten females who were aged 49-76 when they died.