Analysis of the impact of non-compulsory measures on human mobility in Japan during the COVID-19 pandemic.

To curb the spread of the COVID-19 pandemic, countries around the world have imposed restrictions on their population. This study quantitatively assessed the impact of non-compulsory measures on human mobility in Japan during the COVID-19 pandemic, through the analysis of large-scale anonymized mobile-phone data. The non-negative matrix factorization (NMF) method was used to analyze mobile statistics data from the Tokyo area. The results confirmed the suitability of the NMF method for extracting behavior patterns from aggregated mobile statistics data. Data analysis results indicated that although non-pharmaceutical interventions (NPIs) measures adopted by the Japanese government are non-compulsory and rely largely on requests for voluntary self-restriction, they are effective in reducing population mobility and motivating people to practice social distancing. In addition, the current study compared the mobility change in three cities (i.e., Tokyo, Osaka, and Hiroshima), and discussed their similarity and difference in behavior pattern changes during the pandemic. It is expected that the analytical tool proposed in this study can be used to monitor mobility changes in real-time during the pandemic, as well as the long-term evolution of population mobility patterns in the post-pandemic phase.

Incidence and risk factors for hyperkalaemia in patients treated for COVID-19 with nafamostat mesylate.

WHAT IS KNOWN AND OBJECTIVE: Nafamostat mesylate (NM) is used clinically in combination with antiviral drugs to treat coronavirus disease (COVID-19). One of the adverse events of NM is hyperkalaemia due to inhibition of the amiloride-sensitive sodium channels (ENaC). The incidence and risk factors for hyperkalaemia due to NM have been studied in patients with pancreatitis but not in COVID-19. COVID-19 can be associated with hypokalaemia or hyperkalaemia, and SARS-CoV-2 is thought to inhibit ENaC. Therefore, frequency and risk factors for hyperkalaemia due to NM may differ between COVID-19 and pancreatitis. Hyperkalaemia may worsen the respiratory condition of patients. The objective of this study was to determine the incidence and risk factors for hyperkalaemia in COVID-19 patients treated with favipiravir, dexamethasone and NM. METHODS: This retrospective study reviewed the records of hospitalized COVID-19 patients treated with favipiravir and dexamethasone, with or without NM, between March 2020 and January 2021. Multivariable logistic regression analysis was performed to identify the risk factors for hyperkalaemia. RESULTS AND DISCUSSION: Of 45 patients who received favipiravir and dexamethasone with NM for the treatment of COVID-19, 21 (47%) experienced hyperkalaemia. The duration of NM administration was a significant predictor of hyperkalaemia (odds ratio: 1.55, 95% confidence interval: 1.04-2.31, p = 0.031). The receiver-operating characteristic curve analysis determined that the cut-off value for predicting the number of days until the onset of hyperkalaemia was 6 days and the area under the curve was 0.707. WHAT IS NEW AND CONCLUSION: This study revealed that the incidence of hyperkalaemia is high in patients treated for COVID-19 with NM, and that the duration of NM administration is a key risk factor. When NM is administered for the treatment of COVID-19, it should be discontinued within 6 days to minimize the risk of hyperkalaemia.