COVID-19-related stress, exercise, and oral health-related quality of life among community-dwelling older adults who participated in the CHEER Iwamizawa project, Japan.

This study examined the association between coronavirus disease 2019 (COVID-19)-related stress, exercise habits, and oral health-related quality of life (OHRQoL) in a sample of 215 community-dwelling older adults in Japan (57 men, 158 women; Mage = 74.2 years, SD = 6.0). Data were collected during wellness checkups in October 2020 and included participants' demographic characteristics, measures of instrumental activities of daily living and depressive tendencies, number of teeth, oral hypofunction, OHRQoL, COVID-19-related stress, and exercise habits. Four mutually exclusive groups were created, using the presence or absence of COVID-19-related stress and lack of exercise habits as risk factors for poor OHRQoL (no COVID-19-related stress and no lack of exercise, COVID-19-related stress only, lack of exercise habits only, and both COVID-19-related stress and lack of exercise habits). Poisson regression with robust standard errors provided the prevalence ratio for poor OHRQoL. The presence of both COVID-19-related stress and lack of exercise habits (adjusted prevalence ratio: 2.20, 95% CI: 1.31- 3.69) was associated with poor OHRQoL. The results indicate that COVID-19-related stress and exercise habits should be considered when designing oral health and public health initiatives.

Development of a Model for the Spread of Nosocomial Infection Outbreaks Using COVID-19 Data.

We constructed and validated a mathematical model of infectious diseases to simulate the impact of COVID-19 nosocomial infection outbreaks outside hospitals. The model was constructed with two populations, one inside the hospital and one outside the hospital, and a population diffusion rate k (0 ≤ k ≤ 1) was set as a parameter to simulate the flow of people inside the hospital to outside the hospital. To validate the model, we divided the values of the population diffusion rate k into k = 0-0.25, 0.25-0.50, 0.50-0.75, and 0.75-1.0, and the initial value at the beginning of the simulation was set as day 1. The number of infected people was calculated for a 60-day period. The change in the number of people infected outside the hospital due to the out-break of nosocomial infection was calculated. As a result of the simulation, the number of people infected outside the hospital increased as the population diffusion rate k increased from 0.50 to 0.75, but the number of people infected from 0.75 to 1.0 was almost the same as that from 0 to 0.25, with the peak day being earlier. In future, it will be necessary to examine epidemiological information that has a large impact on the results.