Background and Objectives: There is an ongoing controversy regarding the risks of restrictive and liberal red blood cell (RBC) transfusion strategies. This meta-analysis assessed whether transfusion at a lower threshold was superior to transfusion at a higher threshold, with regard to thrombosis-related events, that is, whether these outcomes can benefit from a restrictive transfusion strategy is debated. Materials and Methods:We searched PubMed, Cochrane Central Register of Controlled Trials and Scopus from inception up to 31 July 2021. We included randomized controlled trials (RCTs) in any clinical setting that evaluated the effects of restrictive versus liberal RBC transfusion in adults. We used random-effects models to calculate the risk ratios (RRs) and 95% confidence intervals (CIs) based on pooled data.Results: Thirty RCTs involving 17,334 participants were included. The pooled RR for thromboembolic events was 0.65 (95% CI 0.44-0.94; p = 0.020; I 2 = 0.0%, very low-quality evidence), favouring the restrictive strategy. There were no significant differences in cerebrovascular accidents (RR = 0.83; 95% CI 0.64-1.09; p = 0.180; I 2 = 0.0%, very low-quality evidence) or myocardial infarction (RR = 1.05; 95% CI 0.87-1.26; p = 0.620; I 2 = 0.0%, low-quality evidence). Subgroup analyses showed that a restrictive (relative to liberal) strategy reduced (1) thromboembolic events in RCTs conducted in North America and (2) myocardial infarctions in the subgroup of RCTs where the restrictive transfusion threshold was 7 g/dl but not in the 8 g/dl subgroup (with a liberal transfusion threshold of 10 g/dl in both subgroups).Conclusions: A restrictive (relative to liberal) transfusion strategy may be effective in reducing venous thrombosis but not arterial thrombosis.

Objectives: Telemedicine enables patients to communicate with physicians effectively, especially during the COVID-19 pandemic. However, few studies have explored the use of online healthcare platforms for a comprehensive range of specialties during the COVID-19 pandemic. This study aimed to investigate how telemedicine services were affected by the announcement of human-to-human transmission in China. Methods: Telemedicine data from haodf.com in China were collected. A difference-in-differences analysis compared the number of telemedicine use and the number of active online physicians for different specialties in 2020 with the numbers in 2019, before and after the announcement of human-to-human transmission. Results: Data from 2 473 734 telemedicine use during the same calendar time in 2020 and 2019 were collected. Telemedicine use in 2020 increased by 349.9% after the announcement of human-to-human transmission in China, and the number of active online physicians increased by 23.2%. The difference-in-differences analysis indicated that the announcement had statistically significant positive effects on the numbers of telemedicine use for almost all specialties except cosmetic dermatology, pathology, occupational diseases, sports medicine, burn, medical imaging, and interventional medicine. Conclusion: Telemedicine services increased significantly after the announcement of human-to-human transmission of COVID-19. Online activities of most specialties increased except where providers had to conduct in-person testing and provide bedside therapies.