IntroductionAsymptomatic infection of SARS-CoV-2 may lead to silent community transmission and compromise the COVID-19 pandemic control measures. We aimed to estimate the rate of asymptomatic COVID-19 from published studies and compare this rate among different regions and patient groups.MethodsIn this systematic review and meta-analysis, electronic databases including Medline, Embase, PubMed and three Chinese electronic databases (Chinese National Knowledge Infrastructure [CNKI], WanFang Data and China Science, and Technology Journal Database [VIP]) were searched for literature published from 1 November 2019 to 31 December 2020. Original investigations with sample size (or number of subjects) not less than five were included for further analyses. Subgroup analyses were conducted according to different study types, study periods, geographical regions and patient demographics. The STATA (V.14.0) command ‘metaprop’ was implemented to conduct a meta-analysis of the pooled rate estimates of asymptomatic infections with exact binomial and score test-based 95% confidence interval (CI).ResultsA total of 130 123 ascertained COVID-19 infections from 241 studies were included in this meta-analysis, including 31 411 asymptomatic infections. The overall rate of asymptomatic infections was 23.6% (18.5%–29.1%) and 21.7% (16.8%–27.0%) before and after excluding presymptomatic cases, respectively. Subgroup analysis showed that significantly higher in pregnant women (48.8%, 28.9%–68.9%), children (32.1%, 24.2%–40.5%), and studies reporting screening programmes (36.0%, 24.6%–48.1%) conducted on or after 1 March 2020 (42.5%, 33.4%–51.9%). In terms of geographical region, the rate was the highest in Africa (64.3%, 56.7%–71.6%), followed by America (40.0%, 27.4%–53.3%), Europe (28.1%, 19.0%–38.1%) and Asia (18.1%, 13.2%–23.5%).ConclusionWe approximated that one-fifth of COVID-19 infections are asymptomatic throughout the course of infection. Public health policies targeting these high-risk groups may be recommended to achieve early identification and more stringent containment of the pandemic.

This study aims to investigate the molecular characteristics of Chinese gastric cancer patients. In our study, the KRAS , BRAF , and PIK3CA mutation status of 485 GC patients were analyzed by Sanger sequencing. Kaplan-Meier analysis was used to plot survival curves according to different genotypes. The results show that the frequency of KRAS , BRAF and PIK3CA mutations were 4.1%, 1.2% and 3.5%, respectively. BRAF mutations were significantly concentrated in stage III and IV gastric cancer ( P =0.009). KRAS G12V mutation carriers have much shorter OS than other mutation carriers and wild-type group patients ( P =0.013). In conclusion, only the KRAS G12V mutation has an adverse effect on patient survival.

Objective This study aimed to evaluate how the knowledge and perception towards colorectal cancer (CRC) screening had been changed in a large population, and identified factors associated with its participation based on factors pertinent to the Health Belief Model (HBM). Methods Data from 3600 screening participants and 3600 non‐participants were collected through a telephone survey via simple random sampling of telephone numbers in a territory‐wide directory from December 2016 to November 2018. Sociodemographic factors; the enabling factors of screening as well as the barriers of screening were collected. The changes in these factors were evaluated by Pearson's chi‐square trend test. A logistic regression model was constructed to identify the association between the above factors and CRC screening participation. Results The knowledge level (67.9% to 85.4%, p < 0.001), perceived severity of having CRC (37.7%–42.8%, p < 0.01), perceived benefits of screening (54.9%–72.1%, p < 0.001), and reductions in barriers (14.1%–5.1%, p < 0.001) of CRC screening significantly improved among the non‐users. Subjects with older age (adjusted odds ratio (AOR): 2.01, p < 0.001), higher knowledge level of screening methods (AOR: 6.68, p < 0.001), greater perceived severity (AOR: 2.04, p < 0.001) and coverage of insurance (AOR: 1.22, p < 0.01) were more likely to participate. In contrast, more affluent subjects (AOR: 0.69, p < 0.001), female individuals (AOR: 0.63, p < 0.001), higher level of perceived psychological (AOR: 0.54, p < 0.001) and access barriers (AOR: 0.55, p < 0.001) were associated with poorer participation. Conclusion These findings demonstrated a substantial increase in the enabling factors of CRC screening, including knowledge, perceived severity and perceived benefits. The study also identified the target groups such as younger individuals, females and more affluent people among whom more intensive educational initiatives are needed to enhance their participation.

Background The Public Private Interface–Electronic Patient Record (PPI-ePR) system was implemented as a new electronic platform to facilitate collaboration between the public and private sectors in Hong Kong. However, its barriers to participate and benefits have not been comprehensively assessed. Objective This study aimed to evaluate the awareness, acceptance, perceived benefits, and obstacles to participation among private doctors and the general public. Methods From December 2012 to January 2013, 2435 telephone interviews were performed by trained interviewers to survey randomly selected patients who were enrolled or not enrolled in the PPI-ePR system. In addition, self-administered surveys were sent by postal mail to 4229 registered doctors in Hong Kong. The questionnaires for both patients and doctors contained questions on subjects’ awareness, acceptance, and perceptions of the PPI-ePR, perceived benefits and obstacles of participating in the program, reasons for not using the system after enrolling, and perceived areas for service improvement of the system. Results More than 53.1% (266/501) of enrolled patients believed that the PPI-ePR system would improve health care quality by reducing duplicate tests and treatments, while more than 76.8% (314/409) of enrolled doctors emphasized timely access to patients’ medical records as the biggest benefit of their enrollment. Among nonenrolled patients, unawareness of the project was the most popular obstacle to enrolling in the PPI-ePR system (483/1200, 40.3%). Regarding nonenrolled doctors, the complicated registration process hindered them from participating in the program the most (95/198, 48.0%). Television, newspaper, and magazine advertisements and medical profession newsletters or journals were suggested as the most effective means to encourage participation in the program among surveyed patients (1297/1701, 76.2%) and doctors (428/610, 70.2%), respectively. Lack of clinical indication requiring data extraction from other hospitals was the main reason for low level of PPI-ePR use. Conclusions This study comprehensively assessed the popularity, perceived benefits, and hindering factors of enrolling in the PPI-ePR system in Hong Kong. Low levels of awareness, few privacy concerns, and inactive use of the PPI-ePR system were among the key features for patients and physicians. Public promotions, simplified logistics, and a user-friendly online interface were suggested to improve the coverage and effectiveness of health information exchange between private and public health care sectors.