This study used data obtained from anonymized medical records and internet-based questionnaires completed by patients who used AHHC medical services between January 1 and December 31, 2019. The study was reviewed and approved by the Research Ethics Committee of the University of Tsukuba (approval number 1527).
In this study, the anonymized clinical records of all patients who had used the AHHC services during the study period were reviewed, along with the questionnaires they completed. Information regarding patient gender, age, and illness severity were extracted from the medical records. The questionnaire consisted of two questions: what action the patient would have taken in the absence of AHHC services (stay home, wait for consultation until a hospital opens, visit ED, or call an ambulance) and what action was taken within 3 days following the use of the AHHC services (no hospital visit, visited an outpatient clinic, visited an ED, received another house call, or called an ambulance). For patients aged ≤15 years, a questionnaire was administered to parents or guardians who sought AHHC medical services.
Health insurance system in Japan
Japan’s health insurance system provides universal coverage. It provides healthcare services, with the patient paying 10–30% of the medical fee, depending on the income and age of the insured . In addition, many municipalities provide subsidies for patients below 15 years of age to cover their health care costs.
Primary care system in Japan
Japan does not have an established general practitioner system similar to that in European countries . Moreover, family medicine remains unpopular in Japan; thus, primary care is mainly provided by specialists, such as internists and pediatricians, in clinical settings after they have been trained in a hospital .
Emergency care service system in Japan
Emergency hospitals in Japan are categorized as primary, secondary, or tertiary . Generally, for primary care, holiday and night-time EDs in hospitals or clinics are available for non-severe conditions. Secondary hospitals provide emergency first aid for patients and, if necessary, inpatient care. Tertiary hospitals provide tertiary emergency medical and advanced critical care [16, 17]. Ambulatory patients have free access to any hospital facility, regardless of their symptoms. Meanwhile, when a patient calls an ambulance, patients are transported to a secondary or tertiary hospital depending on the illness severity, and 97.9% of callers are transported by ambulance to hospitals [https://www.fdma.go.jp/publication/hakusho/r1/items/r1_all.pdf]. Furthermore, ambulance expenses are covered by taxes [18, 19].
AHHC medical Services in Japan
A private AHHC medical service (Fast Doctors, Shinjuku, Tokyo, Japan) has been operating in Tokyo since 2016. The company operates 7 days per week and provides out-of-hours services (i.e., 19:00–06:00 on weekdays, 18:00–06:00 on Saturdays, and 24 h per day on Sundays and holidays). Patients can access the services via a direct phone call or request an online consultation.
Following a telephone triage, instead of sending an ambulance, the service sends a doctor directly to the patient’s residence. The telephone triage involves a patient calling an emergency telephone consultation service and being classified into one of five categories (red, orange, yellow, green, or white) based on symptom acuity. The red category implies the presence of a life-threatening condition or one that is likely to worsen or change rapidly; orange reflects a condition requiring immediate hospital attendance as the symptom(s) may worsen over time; yellow requires a hospital visit as the symptom(s) may worsen over time; green does not have symptoms listed in the previous categories but requires a hospital visit; and white reflects symptoms that do not require a hospital visit .
The AHHC doctors conduct home visits for patients classified as orange and yellow; for those classified as red, an ambulance is called; patients classified as green are provided with information about nearby clinics or a primary hospital; and patients classified as white are provided appropriate advice for home observation.
After the consultation, the AHHC doctors classify the patient’s illness severity into one of the three following categories: mild (can be treated using over-the-counter medications), moderate (require a hospital or clinic visit), or severe (require ambulance transportation) [20, 21].
Additional costs for an out-of-hours visit in Japan
In hospitals and clinics, if a patient visits out of hours, they incur an out-of-hours charge in addition to the regular medical fee. There are three types of out-of-hour charges (covered by Japan’s universal health care system), depending on when such services are sought: after hours (06:00–08:00 and 18:00–22:00 on weekdays; 06:00–08:00 and 12:00–22:00 on Saturdays), midnight (22:00–06:00), and Sundays or public holidays.
In an AHHC medical service, patients are charged the regular medical fee, an out-of-hour home visit fee (covered by Japan’s universal health care system), and transportation (0.27 USD per kilometer, up to 8.7 USD).
We compared the patient characteristics (age, gender, and illness severity) between questionnaire responders and non-responders. As appropriate, Pearson’s chi-square test or Fisher’s exact test were used to compare categorical variables, and Student’s t-test or the Wilcoxon-Mann-Whitney test were used to compare continuous variables. Analyses were performed using JMP 14.3 statistical software (SAS Institute, Cary, NC, USA), and a value of p < 0.05 was considered statistically significant.