Association between personality traits and self-care behaviors in patients with gastrointestinal cancer undergoing outpatient chemotherapy

Purpose Practicing self-care behaviors is important for patients with gastrointestinal cancer undergoing outpatient chemotherapy. Knowledge of personality traits may be useful in providing individualized support that can improve self-care behaviors. Therefore, we assessed the association between personality traits and self-care behaviors in these patients. Methods This cross-sectional study was conducted among patients who received intravenous chemotherapy at a designated regional cancer hospital between June 2020 and October 2020. A self-administered survey was conducted among these patients using the Japanese version of the Ten Item Personality Inventory and a 29-item questionnaire to assess self-care behaviors. Association between the scores of the personality traits and frequency of each self-care behavior was analyzed using the Spearman's rank correlation coecient. High degree of openness, characterized by the ability to tackle new situations, had a moderately signicant positive correlation with adjustment of exercise (ρ = 0.49, p<0.01) and activities for a change of mood (ρ = 0.40, p<0.01). High degree of conscientiousness, characterized by the ability to take a health action, had a signicant positive correlation with acquisition of information on disease and treatment (ρ = 0.30, p=0.03) and conrmation of inspection results (ρ = 0.39, p<0.01).


Introduction
The incidence of cancer increases every year, and gastrointestinal cancer accounts for approximately 26% of all cancer cases in the world [1][2] and 42% of all cases in Japan [3]. The ve-year relative survival rate of gastrointestinal cancer has also increased due to early detection of cancer and advances in treatment methods. However, improving the survival rate of gastrointestinal cancer remains a challenge [4]. Even today, recurrence and progression of the disease are a concern for many patients with gastrointestinal cancer, and chemotherapy to prevent recurrence or progression is the main treatment.
Chemotherapy for gastrointestinal cancer involves the use of cytotoxic agents, such as antimetabolites, platinumcontaining preparations, and topoisomerase inhibitors. These drugs have a narrow therapeutic range, and in addition to cancer cells, they also act on healthy cells of the body. Hence, the occurrence of side effects is unavoidable. As patients with cancer undergoing outpatient chemotherapy do not have a medical attendant to assist them in daily life, they are required to monitor, prevent, and cope with the side effects themselves. Insu cient self-care for side effects may lead to more serious consequences, eventually resulting in treatment interruption or discontinuation [5][6]. Moreover, side effects in uence not only the physical well-being but also the psychological and social well-being of the patients, which in turn can negatively in uence their quality of life.
In patients with gastrointestinal cancer, side effects that cause peripheral neuropathy and changes in the appearance may lead to restrictions on activities of daily living, changes in interpersonal relationships, and a reduction in the range of life, which may lead to anxiety and distress [7][8][9][10][11]. As these side effects are di cult to prevent and treat, patients must learn to deal with them by practicing self-care behaviors. Patients must understand their condition, relieve symptoms, devise suitable lifestyles while adjusting activities and roles, and manage psychological stress [8][9]12]. Individualized self-care support aims to understand the diverse living backgrounds of patients and is important for patients to practice and strengthen their self-care behaviors. However, providing individualized support is a challenge given the short-term involvement of outpatients with healthcare professionals and the short duration of treatment [13][14].
Personality comprises a set of traits that indicate individual behavioral tendencies. A unique personality trait can be regarded as individuality [15]. Therefore, personality traits can be useful in explaining and predicting individual behavior [15][16]. Previous studies on patients with cancer and chronic diseases have attempted to investigate the association of personality traits with treatment compliance and behaviors required for disease management, such as medication, diet, and exercise [17][18][19]. These studies reported that conscientiousness and agreeableness are traits associated with therapeutic compliance. Another study reported that the patient's sex, chemotherapy interval, and the presence of counselors are associated with self-care behaviors in those undergoing outpatient chemotherapy [20]. Thus, a knowledge of personality traits may be useful in providing individualized self-care support. However, none of the studies have assessed the association of personality traits with self-care behaviors including managing daily life. Therefore, in this study, we attempted to clarify the association between personality traits and self-care behaviors among patients with gastrointestinal cancer undergoing outpatient chemotherapy.

Methods
In this cross-sectional study, we investigated the quantitative association between personality traits and self-care behaviors of patients with gastrointestinal cancer undergoing outpatient chemotherapy using a self-administered questionnaire. The study was approved by the Observation Research Ethics Review Committee of the Osaka University Hospital (approval number: 20001-3).

Patients
Patients registered in the gastrointestinal surgery department of a designated regional cancer hospital who received intravenous chemotherapy were enrolled in the study. The survey period was between June 2020 and October 2020. The inclusion criteria were as follows: (1) patients aged 20 years or older, (2) those who received one or more courses of outpatient chemotherapy, (3) those who received chemotherapy with a regimen comprising one or more cytotoxic anticancer drugs, (4) those who knew they had been diagnosed with cancer, and (5) those who were able to complete the questionnaire themselves. In addition, patients who were treated with antibody-drug conjugates were included in the study. The exclusion criteria were as follows: (1) those who experienced cognitive decline, and (2) those who were considered by the attending physician to be ineligible for the study.

Procedure
For patients ful lling the eligibility criteria, the attending physician rst verbally requested the patients' cooperation using a lea et that described the study outline at the time of examination. After con rming their willingness to participate in the study, the details of the study procedures were explained to the patients, both in writing and verbally, before treatment initiation. Patients who provided written informed consent were nally included in the study. Questionnaires and reply envelopes were provided to the study participants and the lled questionnaires were submitted by mail. Information related to the age, sex, and disease and treatment status was obtained from the medical records.

Personality traits
Personality traits were assessed using the Japanese version of the Ten Item Personality Inventory (TIPI-J). TIPI-J measures ve personality traits, namely extraversion, agreeableness, conscientiousness, neuroticism, and openness, using 10 questions [21][22]. The patient responds to each question using the 7-point Likert scale, "1: strongly disagree" to "7: strongly agree." After processing the reversal items according to the scoring system, the evaluation was made with 2 to 14 points. The higher the score, the greater the strength of the personality trait. The reliability and validity of TIPI-J were established as reported previously [22].

Self-care behaviors
We created a questionnaire about self-care behaviors essential for patients with cancer undergoing outpatient chemotherapy, such as information search/utilization, self-monitoring, behavior selection/adjustment, utilization of support resources, prevention of/coping with side effects, and psychological care. Two doctors, one pharmacist, and ve nurses specialized in cancer care evaluated the validity of each question. After content validation, a set of 29 questions was nally included in the questionnaire. Participants answered each question using a 4-point scale, with 1 meaning "not at all" and 4 meaning "frequently." Patients' characteristics Demographic data included the age, sex, marital status, cohabitant, educational status, employment status, and performance status based on the scale created by the Eastern Cooperative Oncology Group (ECOG PS). Disease-and treatment-related data included the primary tumor site, tumor stage, treatment history for the current disease, past chemotherapy history, and treatment status for the current regimen (cytotoxic anticancer drugs used, cycle, etc.). We also obtained information related to the physical symptoms (stomatitis, fatigue, nausea/vomiting, loss of appetite, dysgeusia, constipation, diarrhea, peripheral neuropathy, hair loss) and the presence or absence of anxiety. Regarding the status of self-care support, we asked about the content of explanations and support received from healthcare professionals in performing chemotherapy.

Statistical analysis
We used the convenience sampling method for enrollment of participants in the study. All patients ful lling the eligibility criteria were included. Descriptive statistics were used to assess each item of the survey questionnaire. The association between the scores of each of the ve personality traits and the frequency of each self-care behavior was analyzed using the Spearman's rank correlation coe cient. The signi cance level was set to 5% on both sides. All analyses were performed using the statistical software JMP Pro 15.1.0 (SAS Institute Inc., Cary, NC, USA).

Results
Questionnaires were administered to 57 participants, and responses were obtained from 53 (response rate, 93.0%). The responses of 52 participants were included in the nal analysis after excluding 1 response due to inadequacies in the responses to the TIPI-J items and di culty in analyzing the association between personality traits and self-care behaviors (valid response rate, 91.2%).
The mean age±standard deviation (SD) of the participants was 66.1±9.1 years, and there were 35 male participants (67.3%). The most common primary tumor site was the colon/rectum in 24 participants (46.2%). The cytotoxic anticancer drugs most often used in the current regimen were 5-uorouracil in 17 (32.7%) and irinotecan in 16 (30.8%) participants.
Oxaliplatin was used in the current regimen of 13 (25.0%) participants, while 7 (13.5%) participants had it removed from their regimen due to side effects such as peripheral neuropathy (Table 1). g This is the number of courses of chemotherapy administered as part of the current regimen when performing the survey.     , and utilization of support resources in 6 (11.5%); 4 (7.7%) participants reported that they received no information and support pertaining to the above aspects.
The mean score±SD for the personality trait of extraversion was 8.9±2.7, agreeableness was 11.0±1.9, conscientiousness was 8.8±2.7, neuroticism was 6.7±2.8, and openness was 8.9±2.5.  Table 3 shows the correlation coe cient (ρ) between personality traits and self-care behaviors of patients with gastrointestinal cancer undergoing outpatient chemotherapy. Openness and conscientiousness were signi cantly correlated with multiple self-care behaviors.

Discussion
We observed that the personality traits of openness and conscientiousness were signi cantly associated with multiple self-care behaviors required for patients with gastrointestinal cancer undergoing outpatient chemotherapy. High degree of openness was found to be associated with adjustment of exercise and activities, while a high degree of conscientiousness was associated with acquisition of information on disease and treatment and con rmation of inspection results.
Our study was focused on examining self-care behaviors rooted in the daily lives of patients with gastrointestinal cancer and showed that openness was signi cantly associated with the implementation of activity adjustment and ingenuity towards changes in appearance. Previous studies have shown that the intent of exercise is associated with a high degree of openness in patients undergoing chemotherapy [23]; this nding is in agreement with our results that suggest a moderately signi cant positive correlation of openness with adjustment of exercise. Those with a high degree of openness are not bound by existing values and are characterized by actively working on new situations [21][22][24][25].
Therefore, exercise during outpatient chemotherapy may be considered as a new initiative by the patient. Traditionally, it is believed that patients with cancer undergoing chemotherapy tend to refrain from physical activity due to concerns of emerging physical symptoms and side effects [26][27][28]. In our study, exercising moderately according to the physical condition was a frequently practiced self-care behavior reported in less than 30% of the participants. Despite the apparent bene ts of moderate exercise during chemotherapy [29], it is a challenging self-care behavior among patients undergoing chemotherapy. Therefore, the attitude and involvement of healthcare professionals can play an important role in supporting patients engaged in new self-care behaviors.
In our study, openness had a moderately signi cant association with applying ingenuity to adapt to changes in appearance. Those with a high degree of openness are also characterized by creativity, imagination, and unique ideas [21][22][24][25]. Side effects of the regimens that patients receive may manifest as changes in their appearance, such as hair loss, weight loss, and hand-foot syndrome [30][31]. For the patients to respond to these changes in appearance and continue activities of daily life, creativity is essential. Therefore, it is understandable that ingenuity is exhibited by those with a high degree of openness. This study suggests that responding to changes in appearance requires support based on the creativity encouraged by openness.
Moreover, our study provides new insights into the association between conscientiousness and self-care behaviors. In our study, conscientiousness was associated with information acquisition about the disease and its treatment, as well as with the expression of thoughts and emotions. Conscientiousness is the will and desire to achieve a goal; it is a trait of carrying out work in a systematic manner [21][22][24][25]32]. Obtaining information about one's disease, treatment, and the examination performed can be considered an action to grasp one's situation and continue both treatment and daily life while having a perspective [12]. This suggests that those who are highly conscientious not only comply with the instructions from their healthcare professionals but also practice self-care behaviors to manage their disease and treatment.
We also observed that conscientiousness was signi cantly associated with the expression of one's thoughts and emotions. In a previous study that investigated the association between personality traits and stress coping patterns in healthy individuals, extroversion and neuroticism were found to be associated with the ability to cope with emotional stress [32]. In our study, there was no association of expression of thoughts and emotions with extroversion or neuroticism; however, there was a signi cant association with conscientiousness which is characterized by practicing healthy behavior. This suggests that the expression of thoughts and emotions may be a self-care behavior that a patient is working hard on. Therefore, it is necessary to create an environment in which patients can express their thoughts and emotions to healthcare professionals with honesty.
To the best our knowledge, ours is the rst study to comprehensively examine the association between personality traits and self-care behaviors practiced by patients with gastrointestinal cancer undergoing outpatient chemotherapy to deal with the physical, psychological, and social impact of the side effects of treatment. Nevertheless, our study has some limitations. First, the implementation of self-care behavior was assessed based on the patients' self-evaluation; therefore, the appropriateness of the reported self-care behavior in individual situations cannot be judged. Second, as this study was a cross-sectional survey, we could only consider the effects of treatment history and treatment processes up to the time of the survey. Lastly, although the purpose of this study was to clarify the association between individual personality trait and self-care behaviors, it has been reported that a collection of individual personality traits is actually re ected in the behavior of a person [15]. Therefore, in future, larger studies are required to assess the association between self-care behaviors and the combination of an individual's personality traits.

Conclusion
The personality traits of openness and conscientiousness are associated with self-care behaviors in patients with gastrointestinal cancer undergoing outpatient chemotherapy and may be useful in explaining and predicting individual self-care behaviors. In the future, it is necessary to conduct larger studies to assess the association between self-care behaviors and the combination of an individual's personality traits. Declarations