Control treatments

A recent Statistical Question described a randomised controlled trial that investigated the efficacy and safety of scorpion antivenom combined with prazosin in the treatment of venomous scorpion sting.1 Individuals were included in the trial if they had grade 2 scorpion envenomation, were older than 6 months, and had no cardiorespiratory or central nervous system abnormalities. The control treatment was prazosin alone, a commonly used vasodilator. Recovery from scorpion sting was significantly quicker after administration of scorpion antivenom combined with prazosin than after prazosin alone.2

Which of the following statements, if any, are true?

a) The control treatment was a negative control …