ABSTRACT
Exploring the spatial patterns of COVID-19 transmission and its key determinants could provide a deeper understanding of the evolution of the COVID-19 pandemic. The goal of this study is to investigate the spatial patterns of COVID-19 transmission in different periods in Singapore, as well as their relationship with demographic and built-environment factors. Based on reported cases from 23 January to 30 September 2020, we divided the research time into six phases and used spatial autocorrelation analysis, the ordinary least squares (OLS) model, the multiscale geographically weighted regression (MGWR) model, and dominance analysis to explore the spatial patterns and influencing factors in each phase. The results showed that the spatial patterns of COVID-19 cases differed across time, and imported cases presented a random pattern, whereas local cases presented a clustered pattern. Among the selected variables, the supermarket density, elderly population density, hotel density, business land proportion, and park density may be particular fitting indicators explaining the different phases of pandemic development in Singapore. Furthermore, the associations between determinants and COVID-19 transmission changed dynamically over time. This study provides policymakers with valuable information for developing targeted interventions for certain areas and periods.
ABSTRACT
The therapeutic effect of tocilizumab remains controversial. We aimed to evaluate whether tocilizumab might be beneficial in COVID-19 patients. We searched PubMed, Embase and Cochrane library from inception to June 23, 2020. Summary estimates of overall response rate (ORR) and all-cause death rate in all patients were analyzed. This study was registered with PROSPERO (CRD42020191313). We included data from 28 articles including 991 COVID-19 patients who underwent tocilizumab administration. The pooled ORR was 72% (95% CI, 66-79%) and pooled all-cause death rate was 16% (95% CI, 11-22%). The optimal timing of administration was the 7.15 day from the symptom onset and with the lowest death rate of 13.11%. 562 patients were defined as with severe infection, and the pooled ORR was 78% (95% CI, 70-85%). The pooled ORR of 56 organ transplantation recipients was 53% (95% CI, 26-78%), which was lower than non-transplant patients [75% (95% CI, 69-81%)]. Nearly all studies confirmed the safety of tocilizumab administration. Tocilizumab improves the clinical outcome of COVID-19 patients, especially in severe cases, and the optimal timing of administration may provide the guidance for management. However, tocilizumab may be used with caution in solid transplant recipients for the suboptimal efficacy.