BCG and COVID-19 : correlation or causality or neither?

Abstract

LEARNING OUTCOMES: The learning outcome is to understand the difference between correlation and causation. CASE OVERVIEW/SYNOPSIS: The case is set during the period of the COVID-19 pandemic, globally a search for effective treatments were underway. An initial forerunner that was being considered was Bacille Calmette-Guerin (BCG), given its effectiveness in the treatment of tuberculosis and other pulmonary-related infections. While there were a lack of randomised controlled trials, initial data from publicly related secondary data sources indicated that, in countries with BCG inoculation policies, the severity of the spread and mortality of COVID-19 was muted. The case is centered around the available information on BCG and COVID-19. COMPLEXITY ACADEMIC LEVEL : Post-graduate students learning statistics as part of a degree programme. The case assumes no prior statistics knowledge and therefore is aimed at teaching the difference between correlation and causation.