Background: In South Korea, the number of coronavirus disease (COVID-19) cases has declined rapidly and much sooner than in other countries. South Korea is one of the most digitalized countries in the world, and YouTube may have served as a rapid delivery mechanism for increasing public awareness of COVID-19. Thus, the platform may have helped the South Korean public fight the spread of the disease. Objective: The aim of this study is to compare the reliability, overall quality, title–content consistency, and content coverage of Korean-language YouTube videos on COVID-19, which have been uploaded by different sources. Methods: A total of 200 of the most viewed YouTube videos from January 1, 2020, to April 30, 2020, were screened, searching in Korean for the terms “Coronavirus,” “COVID,” “Corona,” “Wuhan virus,” and “Wuhan pneumonia.” Non-Korean videos and videos that were duplicated, irrelevant, or livestreamed were excluded. Source and video metrics were collected. The videos were scored based on the following criteria: modified DISCERN index, Journal of the American Medical Association Score (JAMAS) benchmark criteria, global quality score (GQS), title–content consistency index (TCCI), and medical information and content index (MICI). Results: Of the 105 total videos, 37.14% (39/105) contained misleading information; independent user–generated videos showed the highest proportion of misleading information at 68.09% (32/47), while all of the government-generated videos were useful. Government agency–generated videos achieved the highest median score of DISCERN (5.0, IQR 5.0-5.0), JAMAS (4.0, IQR 4.0-4.0), GQS (4.0, IQR 3.0-4.5), and TCCI (5.0, IQR 5.0-5.0), while independent user–generated videos achieved the lowest median score of DISCERN (2.0, IQR 1.0-3.0), JAMAS (2.0, IQR 1.5-2.0), GQS (2.0, IQR 1.5-2.0), and TCCI (3.0, IQR 3.0-4.0). However, the total MICI was not significantly different among sources. “Transmission and precautionary measures” were the most commonly covered content by government agencies, news agencies, and independent users. In contrast, the most mentioned content by news agencies was “prevalence,” followed by “transmission and precautionary measures.” Conclusions: Misleading videos had more likes, fewer comments, and longer running times than useful videos. Korean-language YouTube videos on COVID-19 uploaded by different sources varied significantly in terms of reliability, overall quality, and title–content consistency, but the content coverage was not significantly different. Government-generated videos had higher reliability, overall quality, and title–content consistency than independent user–generated videos.

Objective. Warfarin use in scleroderma (SSc)-associated pulmonary arterial hypertension (PAH) and idiopathic PAH (IPAH) is controversial. A prerequisite for a trial is the demonstration of community uncertainty. We evaluated experts’ beliefs about the effect of warfarin on 3-year survival in SSc-PAH and IPAH, and factors that influence warfarin use. Methods. PAH experts attending the 2008 American College of Rheumatology or American Thoracic Society meetings expressed the probability of 3-year survival without and with warfarin and their degree of uncertainty by applying adhesive dots, each representing a 5% weight of probability, in “bins” on a line, creating a prior probability distribution or prior. Using a numeric rating scale, participants rated factors that influence their use of warfarin. Results. Forty-five experts (44% pulmonologists, 38% rheumatologists, 16% cardiologists, 2% internists) underwent the belief elicitation interview. In SSc-PAH, the mean probabilities of 3-year survival without and with warfarin were 54% and 56%, respectively. Pessimistic experts believe that warfarin worsens survival by 7%. Optimistic experts believe that warfarin improves survival by 13%. In IPAH, the mean probabilities of 3-year survival without and with warfarin were 68% and 76%. Factors (mean rating out of 10, 0 = not at all important, 10 = extremely important) that influence experts’ use of warfarin were functional class (5.4), age (5.4), pulmonary artery pressure (5.2), peripheral vascular disease (3.6), disease duration (2.8), and sex (1.7). Conclusion. Bayesian priors effectively quantify and illustrate experts’ beliefs about the effect of warfarin on survival in SSc-PAH and IPAH. This study demonstrates the presence of uncertainty about the effect of warfarin, and provides justification for a clinical trial.

Chung JW, et al. Korean Circ J. 2010 Apr;40(4):165-171. http://dx.doi.org/10.4070/kcj.2010.40.4.165