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Profile of Patients with Novel Coronavirus Disease 2019 (COVID-19) in Osaka Prefecture, Japan: A Population-Based
Taro Takeuchi1, Tomoka Imanaka2, Yusuke Katayama2
1Department of Social Medicine, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
Insights
In Osaka, Japan, COVID-19 patients most commonly experienced fever. Older adults faced significantly higher mortality risks from the disease, highlighting a critical public health concern.
Area of Science:
- Epidemiology
- Public Health
- Infectious Diseases
Background:
- Limited data exists on the epidemiological characteristics of coronavirus disease 2019 (COVID-19) patients in Japan.
- Understanding these characteristics is crucial for effective public health interventions and resource allocation.
Purpose of the Study:
- To describe the epidemiological features of COVID-19 patients in Osaka Prefecture, Japan.
- To identify factors associated with mortality among COVID-19 patients.
Main Methods:
- Retrospective observational study utilizing publicly collected data from February 1 to May 31, 2020.
- Analysis of polymerase chain reaction (PCR)-confirmed COVID-19 cases in Osaka Prefecture.
- Cox proportional-hazards model applied to assess mortality risk factors, including age group and sex.
Main Results:
- 5.7% of individuals tested for COVID-19 were positive. Fever (76.6%) and cough (44.3%) were the most frequent symptoms.
- A total of 86 deaths were recorded among 1782 confirmed cases.
- Mortality risk increased substantially with age: HRs ranged from 12.02 for ages 60-69 to 144.71 for ages ≥90, compared to ages 0-59.
Conclusions:
- Fever is the predominant symptom of COVID-19 in Osaka, Japan.
- Advanced age is a significant risk factor for mortality in COVID-19 patients in this region.
- Findings underscore the need for targeted protective measures for elderly populations during COVID-19 outbreaks.
Abstract:
Little is known about the epidemiological characteristics of patients with coronavirus disease 2019 (COVID-19) in Japan. This is a retrospective observational study of COVID-19 patients; study was conducted from February 1 to May 31, 2020. We used publicly collected data on cases of COVID-19 confirmed by polymerase chain reaction (PCR) testing in Osaka Prefecture, Japan. We described the patient characteristics. The Cox proportional-hazards model was applied to evaluate the association between factors (sex, onset month, age group, city of residence) and mortality, and hazard ratios (HRs) with 95% confidence intervals were estimated. During the study period, 5.7% (1782/31,152) of individuals who underwent PCR testing for COVID-19 showed positive results. Among 244 patients with information on symptoms, the most common symptom was fever (76.6%), followed by cough (44.3%). Of the 1782 patients, 86 patients died. Compared with those aged 0-59 years, higher mortality was observed among those aged 60-69 years (HR: 12.02 [3.37-42.93]), 70-79 years (HR: 44.62 [15.16-131.30]), 80-89 years (HR: 68.38 [22.93-203.89]), and ≥90 years (HR: 144.71 [42.55-492.15]). In conclusion, in Osaka Prefecture, Japan, the most common symptom was fever, and older adults had higher mortality among COVID-19 patients.
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