NIPH Clinical Trials Search

Descriptive and Analytical Epidemiological Study of a Hospital Outbreak of COVID-19: A Retrospective Cohort Study

Basic Information

Recruitment status	Pending
Health condition(s) or Problem(s) studied	COVID-19
Date of first enrollment	10/12/2025
Target sample size	20
Countries of recruitment
Study type	Observational
Intervention(s)

Outcome(s)

Primary Outcome	attributable risk, percent attributable risk
Secondary Outcome

Key inclusion & exclusion criteria

Age minimum	Not applicable
Age maximum	Not applicable
Gender
Include criteria	Hospitals located in the Tokai region in which COVID-19 outbreaks have occurred between January 2022 and the end of September 2025. Information is provided by the infection control personnel at each hospital, who are responsible solely for responding to interviews conducted during the collection of information on eligible individuals. All outbreak cases that meet the following case definition will be included. A COVID-19 outbreak is defined as the occurrence of five or more COVID-19-positive individuals within a hospital ward or department during any one-week period. Hospitals in which a COVID-19 outbreak occurred and that had obtained Infection Prevention and Control Enhancement Fee 1 or 2 at the time of the outbreak. The period from the onset of a specific outbreak occurring in or after January 2022 until the outbreak is determined to have ended. The outbreak period is defined as starting 48 hours prior to the symptom onset of the first confirmed case of nosocomial COVID-19 and ending on the day when no new cases are identified. Hospital staff and inpatients who were present in the affected ward or department during the outbreak period. A positive result on nucleic acid detection tests, quantitative antigen tests, or qualitative antigen tests.
Exclude criteria	Hospital staff and inpatients with insufficient data.