In this study, we show that among patients seeking an AHHC medical service in Japan, the proportion of patients with fever or common cold symptoms was slightly lower, but the severity of those patients was substantially higher in the COVID-19 exposure period than in the control period.
Reduction in the proportion of patients with fever or common cold symptoms
The proportion of patients with fever or symptoms of the common cold was slightly lower during the pandemic exposure period than that during the control period, and it decreased sharply in April, 2020. We had initially hypothesized that patients with fever or common cold symptoms may be reluctant to visit hospitals due to the risk of cross-infection and may have been concerned about which hospitals to approach, thus increasing the demand for the AHHC medical services after the start of the COVID-19 pandemic. However, the proportion of patients with fever or common cold symptoms seeking the AHHC medical service clearly decreased, particularly among patients < 65 years of age in April, 2020.
The reason for this finding may be the initial declaration of a state of emergency in seven prefectures, including Tokyo, which occurred on April 7, 2020. Thereafter, many companies requested their employees to work from home, conduct meetings remotely, and restrict entry to the office, thereby achieving the government's goal of an 80% reduction in person-to-person contact ; this resulted in lower seasonal influenza activity in 2020 than in previous years . In addition, this may have led to an increase in the opportunity of students and working people to consult a clinic or hospital during business hours. As for sick children, one parent could take the child to a pediatric clinic or hospital during business hours, while the other watched the other children at home.
Increase in the proportion of patients’ severity
In contrast, the proportion of patients with more severe conditions was higher in the exposure period than in the control period. In Japan, at the beginning of the COVID-19 pandemic, patients with 1) a cold or a fever of ≥ 37.5ºC lasting for ≥ 4 days and 2) intense malaise or dyspnea, were recommended to consult a public health center as per the Japanese government guidelines. Thus, patients with fever or symptoms of the common cold may have refrained from visiting a hospital or a clinic, leading to a decrease in the number of patients in these medical settings; these patients may also have refrained from seeking an AHHC medical service, but would likely have resorted to one after becoming severe.
Patients with COVID-19 can progress to respiratory failure within hours [14-16]; in particular, those who are older in age and have chronic medical conditions have been associated with higher mortality [17-21]. In addition, EDs have been denying admission to some patients suspected of carrying SARS-CoV-2. For instance, in Tokyo, ED staff denied admission to an 80-year-old man suspected of having COVID-19 in 120 different hospitals . Since early detection is crucial for older patients with fever, the AHHC medical service can contribute to early detection and reduce a patient’s hesitation to call an ambulance.
Reducing the risk of cross-infections
The AHHC medical team identified 6 individuals with COVID-19 by SARS-CoV-2 testing. Direct person-to-person contact via respiratory droplets or indirect contact by touching the eyes, nose, or mouth after touching infected surfaces is the main transmission pathway of SARS-CoV-2 . The Centers for Disease Control have recommended that outpatients with suspected COVID-19, including those awaiting test results, should stay at home and isolate themselves from other people ; however, in Japan, people need to visit a clinic or a hospital for SARS-CoV-2 testing. Thus, outpatients in the ED or those on the way to the ED are likely to have contributed to transmission. In the AHHC medical service, doctors wearing PPE visit patients at home, likely reducing the risk of cross-infections in the community and hospital.
Reduction of the burden on emergency departments for patients with fever or symptoms of the common cold
The AHHC service provided more than 7,000 medical services since the start of the COVID-19 pandemic. On April 20, 2020, 9 prefectures, including Tokyo, reported that their hospitals were already at 80% capacity, and a public broadcaster in Japan reported that a patient with COVID-19 symptoms had been turned away by 80 hospitals in Tokyo . Outpatient management is appropriate for most patients with COVID-19; in approximately 80% of the patients, the illness is mild and does not warrant medical intervention or hospitalization . Thus, the AHHC medical service might have been a buffer for consultations for patients with suspected COVID-19.
Reducing the burden on public health centers, clinics, and patients
In Japan, at the beginning of the COVID-19 pandemic, the public health center advised patients to visit a medical institution designated for SARS-CoV-2 infectious diseases. After the initial period, the public health center and medical institution gradually became busier; thus, the administration asked general clinics and hospitals to receive patients with fever and mild cold symptoms. However, many clinics and hospitals were reluctant to examine patients with fever because of difficulties in achieving proper infection control measures, such as separation of outpatients and inpatients with fever. The AHHC medical service may reduce the burden on public health centers, clinics, and patients due to the AHHC operation, home visits, and direct consultations with the public health center on behalf of the patient.
There were some limitations to the current study. First, we reported only a single AHHC medical service. However, this AHHC service provides more than 18,000 night visits annually and is the largest out-of-hours emergency service in Japan. Second, we only compared two periods. After April 10, 2020, the Japanese government lifted restrictions on first-time patients online or via telephone; thus, patients no longer needed to visit a clinic or a hospital. In addition, telemedicine has been covered by Japan's National Health Insurance program. The medical situation has changed markedly; thus, we only compared the patients from December to April for each period. Finally, the AHHC service has a low usage rate among the elderly who may not be familiar with its use as the AHHC was started in 2016.