The international BRACE trial, investigating the BCG vaccine's efficacy against COVID-19, has found it does not reduce healthcare workers' risk of contracting the disease. Future studies will explore the vaccine's influence on other infections and COVID-19 vaccine responses. A world-leading inter
In practice, missing data are very common in real data processing. The reasons may comprise data entry errors, information hiding, or fraud. In this article, we will discuss in which cases incorrect handling of missing data by simple methods will lead to errors in models and decision-making.