Development and validation of a nomogram to predict failure of 14-day negative nucleic acid conversion in adults with non-severe COVID-19 during the Omicron surge: a retrospective multicenter study.

BACKGROUND: With the variability in emerging data, guidance on the isolation duration for patients with coronavirus disease 2019 (COVID-19) due to the Omicron variant is controversial. This study aimed to determine the predictors of prolonged viral RNA shedding in patients with non-severe COVID-19 and construct a nomogram to predict patients at risk of 14-day PCR conversion failure. METHODS: Adult patients with non-severe COVID-19 were enrolled from three hospitals of eastern China in Spring 2022. Viral shedding time (VST) was defined as either the day of the first positive test or the day of symptom onset, whichever was earlier, to the date of the first of two consecutively negative PCR tests. Patients from one hospital (Cohort I, n = 2033) were randomly grouped into training and internal validation sets. Predictors of 14-day PCR conversion failure were identified and a nomogram was developed by multivariable logistic regression using the training dataset. Two hospitals (Cohort II, n = 1596) were used as an external validation set to measure the performance of this nomogram. RESULTS: Of the 2033 patients from Cohort I, the median VST was 13.0 (interquartile range: 10.0‒16.0) days; 716 (35.2%) lasted > 14 days. In the training set, increased age [per 10 years, odds ratio (OR) = 1.29, 95% confidence interval (CI): 1.15‒1.45, P < 0.001] and high Charlson comorbidity index (OR = 1.25, 95% CI: 1.08‒1.46, P = 0.004) were independent risk factors for VST > 14 days, whereas full or boosted vaccination (OR = 0.63, 95% CI: 0.42‒0.95, P = 0.028) and antiviral therapy (OR = 0.56, 95% CI: 0.31‒0.96, P = 0.040) were protective factors. These predictors were used to develop a nomogram to predict VST > 14 days, with an area under the ROC curve (AUC) of 0.73 in the training set (AUC, 0.74 in internal validation set; 0.76 in external validation set). CONCLUSIONS: Older age, increasing comorbidities, incomplete vaccinations, and lack of antiviral therapy are risk factors for persistent infection with Omicron variant for > 14 days. A nomogram based on these predictors could be used as a prediction tool to guide treatment and isolation strategies.

Bullet screen in pre-clinical undergraduate pharmacology education: a survey study.

BACKGROUND: The lack of interaction and communication in pharmacology courses, especially since the onset of the coronavirus disease 2019 (COVID-19) pandemic, which required a fast shift to remote learning at medical schools, leads to an unsatisfactory learning outcome. New interactive teaching approaches are required to improve pharmacology learning attention and interaction in remote education and traditional classrooms. METHODS: We introduced bullet screens to pharmacology teaching. Then, a survey was distributed to first-, second- and third-year pre-clinical undergraduate medical and nursing students at the Shanghai Jiao Tong University School of Medicine from November 2020 to March 2022. We evaluated the essential features, instructional effectiveness, and entertainment value of bullet screens. Responses to structured and open-ended questions about the strengths and weaknesses of the bullet screen and overall thoughts were coded and compared between medical and nursing students. RESULTS: In terms of essential features, bullet screens have a high degree of acceptability among students, and this novel instructional style conveniently increased classroom interaction. Considering instructional effectiveness, bullet screen may stimulate students' in-depth thinking. Meanwhile, students tended to use bullet-screen comments as a way to express their support rather than to make additional comments or to express their different viewpoints. The entertainment value of bullet screen was noteworthy. The lack of ideas might lead to relative differences between medical and nursing students, indicating that guiding the appropriate use of bullet screen is necessary. CONCLUSIONS: The bullet screen may be popularized as an auxiliary teaching approach to promote interaction between teachers and students in the classroom as well as during remote education. It is an interesting and beneficial tool in pharmacology courses, yet there are several aspects of this device that should be improved for popularization.