Real-World Data on Home End-Of-Life Care for Elderly Cancer Patients: A Yokohama Original Medical Database-Based Retrospective Analysis

Abstract

is approximately 30 minutes away from central Tokyo by train and represents a corner of the Tokyo Metropolitan area. Updated vital statistics predict that the percentage of older individuals in Yokohama City will exceed 25% in 2025 and 30% in 2035 [2]. The proportions of patients aged > 65 years who died from cancer (from 2014 to 2015) were 83.1% in Yokohama City [3] and 84.2% nationally according to data from the National Cancer Center [2]. With the growth in the aging population, the proportion of elderly people expected to die from cancer is estimated to increase to 88.2% by 2025 [3]. Thus, it is important to focus on cancer care for the elderly.
Most cancer patients in Japan have so far spent the last moments of their lives in hospitals. However, due to the abovementioned factors, it is anticipated that there will be bed shortages for end-of-life care of terminal stage cancer patients, and meeting this increased demand for elderly cancer patients is a vital social concern. Therefore, a community-based integrated care system is being promoted as an important health care initiative in Japan. However, the actual status of clinical practice with respect to the number of planned home visits (p-HVs), a home visit with a request from a patient (emergent home visits [e-HVs]), immediate home visits (i-HVs), and the detailed medical treatment has not yet been clearly de ned. Moreover, real-world data on the overall survival after the transition to home medical care are limited.
Although the government values home medical care and community-based integrated care systems for meeting the urgent needs in Japan, pain control becomes challenging when cancer patients are accepted into family clinics, and the doctors need to have extensive experience of palliative care. Thus, the number of doctors who accept cancer patients for end-of-life care is limited. To motivate family doctors to accept such patients, details of the burden of home medical care for cancer patients need to be provided. In contrast to Japanese situation, in Canada, which is known as a well-organized country in the implementation of palliative care, the location of death at home exceeds 60% in elderly people [4]. In addition, in many studies, the effectiveness of end-of-life care has been proven through population-based studies [4,5]. The community-based care is recommended to achieve better palliative care [6].
Awareness of the current situation of home end-of-life care (HEC) is indispensable to understand future supply and demand balance. Thus, we aimed to evaluate the current situation of HEC for elderly cancer patients in Yokohama City using an original administrative database to achieve further dissemination of HEC. Unlike existing medical databases such as registry records of speci c diseases, this database was developed for policymaking at the local government level. It is expected to be the rst step of evidencebased policymaking (EBPM) through the gathering of information on medical policy problems, which was recommended by The Center for Government Excellence at Johns Hopkins University [7].

Database and setting
Yokohama City is the most populous city in Japan and is governed by the local government for the Greater Tokyo Area, which includes Tokyo metropolis. Yokohama City has a population of approximately 3.75 million (January 2021), and the population distribution is as follows: individuals aged < 15 years, Public Assistance. The National Health Insurance is a system for farmers, self-employed people, and other such individuals. The Long Life Medical Care System is the system for all individuals aged ≥ 75 years. The personal numbers of insurance and Public Assistance are hashed to protect the identity of individuals, and information that could reveal an individual's identity, such as their name and treatment details, is deleted to make the database secure.
This database includes 68.3% of Yokohama City residents aged 65-69 years; 84.1% of residents aged 70-74 years, with 99.7% of them aged 75-79 years; and 98.6% of residents aged > 80 years. Hence, it has a strong representation of the elderly and is an especially reliable database for those older than 75 years.

Case selection
The data from 2014 and 2015 included those of 2,486,834 people and 29,411,895 medical invoices. Target patients were selected based on three criteria: age ≥ 65 years, death caused by a malignant neoplasm based on International Classi cation of Diseases (ICD)-10 codes (C00-C97), and additional HEC charges. The additional charge could have been applied by an insurance-participating medical facility when planned/emergent home medical care and nursing visits were provided more than twice for a total of 15 days (within 14 days before the day of death).
HEC was classi ed based on the three types of home visits as follows: p-HV, e-HV, and i-HV. Furthermore, i-HVs were divided according to the timing of the visit as follows: daytime i-HV (visit during clinic hours), midnight i-HV (visit from 22:00 to 06:00), and night/holiday i-HV (visit at a time other than clinic hours and midnight). These classi cations were consistent with the medical fee point system in Japan.
Medical fee point data related to home medical care (coded as C000 to C171-2) were obtained based on the invoice of medical treatment for the target patients during the 2-year period and were analyzed. Admission was de ned as the claim of the basic admission fee (coded as A100-109) or special admission fee (coded as A300-317), including admission to the critical care unit, intensive care unit, high care unit, palliative care unit, and community-based integrated care unit.
Emergent admission could not be directly con rmed due to the payment system. Cases with data on planned/emergent home medical care fee and hospitalization fee in the following month were referred to as cases of emergent hospitalization. Survival time at home was de ned as the period from the rst home medical care event to the month in which the additional fee for end-of-life care was charged.
Comparisons were made between the groups of patients aged < 80 years and ≥ 80 years. Statistical analyses were performed using Student's t-test (to compare the time of e-HV and i-HV and the number of home visits per month), χ 2 test (to compare baseline characteristics, emergent admission, central venous nutrition, oxygen use, opioid use, p-HVs by doctors or nurses three times a week or more, and death at home), and multiple regression (to compare survival time after HEC introduction). Sex, insurance type, and type of institution were added as covariates in the multiple regression analysis. P values < 0.05 were considered statistically signi cant. All statistical analyses were performed using Statistical Package for the Social Sciences, version 27 (International Business Machines Corporation, Armonk, NY, USA).

Baseline characteristics
The complete data for 2014 and 2015 included those of 1,239,426 and 1,247,408 people and 14,467,489 and 14,944,496 medical invoices, respectively. Our algorithm showed that 1,323 people had planned to receive HEC. The baseline characteristics of the patients are shown in Table 1.

Results of home end-of-life care (HEC)
The clinical performance and outcome index of HEC are shown in Table 2. The average number of overall e-HVs was 1.3 times per person-month. The < 80-year group received more e-HVs than the ≥ 80-year group (1.5 vs. 1.2 times/person-month, p < 0.001), especially outside the outpatient clinic (p = 0.001). The rate of emergent admission was 5.9% in the ≥ 80-year group, which was higher than that in the < 80-year group (3.1%; p = 0.018). Conversely, the rates of central venous nutrition and opioid use were higher in the < 80-year group than those in the ≥ 80year group. The need for more than 3 days of HVs and/or nursing visits per week, the rate of death in the patient's home, and oxygen use were not signi cantly different between the two groups.
The maximum numbers of p-HVs and e-HVs per month within 6 months from death are shown in Fig. 1. The average number of home visits for all patients was 5.1 ± 2.6. There was no difference in the number of home visits per month between the two groups (5.1 vs. 5.0, p = 0.267).

Survival time after HEC introduction
The survival time after HEC introduction is shown in Fig. 2. The average overall survival time at home was 3.9 ± 4.4 months. The average survival time at home was longer in the ≥ 80-year group than that in the < 80-year group (4.6 vs. 2.9 months, p < 0.001). Moreover, in the multiple regression analysis adjusted for sex and the location of the home care clinic (in Yokohama or a neighboring city), the average survival time at home was signi cantly longer in the ≥ 80-year group than in the < 80-year group (β = 0.17, R 2 = 0.54, p < 0.001).

Discussion
To promote the concept of EBPM, we analyzed an original and large local government-based medical database consisting of medical invoice data. We found that patients received HEC regardless of their cancer type and that their average overall survival time at home was 3.9 months, which was longer than we expected. Furthermore, through our analysis, the necessary home medical care resources and monthly frequency of HVs were identi ed. This comprehensive database analysis with a high coverage of individuals aged ≥ 65 years showed that terminal cancer patients older than 80 years were less dependent on home medical care and had a better prognosis at home. To the best of our knowledge, this is the rst such analysis performed using a large, local government-based medical administrative database in Japan.
One of the signi cant contributions of this study was that it provided high-value real-world data on survival time after HEC introduction, which is di cult to analyze through medical invoice data in the Japanese system wherein survival time cannot be directly obtained. The YoMDB is strongly representative of the elderly population because the insurance system in Japan focuses on this population [8]. Moreover, the YoMDB is a highly comprehensive database for those older than 65 years. This universality is useful for EBPM. We targeted patients aged ≥ 65 years in this study because the proportion of patients aged ≥ 65 years who died of cancer was > 83% [3]. Therefore, such a focused analysis was important from the viewpoint of advancing medical care in the near future for an aging society.
In the Japan HOspice and Palliative care Evaluation study, which was the rst large nationwide study focusing on end-of-life care that surveyed bereaved families, home hospice care was found to be superior to end-of-life care at a cancer center in terms of the overall care satisfaction of the bereaved family, care evaluation scale scores [9], and good death inventory scores [10]. In another cohort study, cancer patients receiving HEC were found to have a better prognosis than those receiving hospital care [11].
Elderly patients with advanced disease, especially cancer patients, preferred HEC (odds ratio, 3.72) [12]. There is a trend for an increase in the number of cancer patients aged ≥ 65 years who want to die in their homes [12]. This nding is similar to that obtained in a previous Japanese study, which demonstrated that 72.8% of Japanese individuals would like to spend the end of their lives at home if they are diagnosed with cancer [13]; approximately 80% of those in their 70s desired to spend their last moments at home [13]. However, 41.6% of respondents thought that this would be di cult to accomplish [13], which highlights the problems of social support and medical resource shortage.
In our study, the elderly could spend more time at home than expected. A retrospective study of home palliative care in 450 patients with advanced cancer in Japan showed poorer prognosis than that reported in our study [14]. We believe that this difference arises from the differences in the nature of the hospital-based medical record database. On the contrary, our administrative database had high coverage because it contained real-world data.
The YoMDB is a useful administrative database for analyzing real-world data as it contains data of local residents in Yokohama City. Health care policymaking is essential for ensuring a healthy society; thus, evidence-based policies, similar to those used to treat a patient in a hospital or clinic, should be developed. There is an urgent need to develop human resources responsible for home medical care and a medical care provision system that can meet the increasing demand for HEC for elderly cancer patients in the near future. A local government and local medical association that manage a community-based integrated care system should proceed to increase the number of home care clinics involving cancer terminal care. An effective question to clinics might be as follows: "How would you like to start HEC for cancer patients from ≥ 80-year patients?" This study has several limitations. First, given the nature of the receipt database (it is based on a xed code for the practice performed), we could not con rm the practice or outcome that we would like to have directly obtained. This may have resulted in some information bias. Second, because the reason for emergency hospitalization could not be correctly determined, it was di cult to analyze in detail whether palliation was acute, whether it was for respite purposes, or whether there was a different underlying requirement. Third, the analyses of medical invoice databases are limited because Japanese receipt data are originally used for the calculation of medical treatment fee, and analysis of the patient's condition and severity of underlying disease or comorbidity using these data was not possible.

Conclusions
This study reported that terminal cancer patients aged ≥ 80 years were less dependent on home medical care and had better prognosis at home than patients aged < 80 years. In areas where the population will continue to age further, such as Japan, the need for HEC for cancer patients will de nitely increase, and the development of social resources to meet this demand is an urgent social issue. Our results are valuable as they can be used as the basis for providing HEC through a community-based integrated care system and will be useful for raising awareness and for human resource development. In particular, for medical institutions that intend to start HEC for cancer patients, starting from patients aged ≥ 80 years could be a useful and concrete rst step as these patients have a relatively low degree of medical dependence.