‘Worm Wars’: The Unravelling of the Randomised Control Trial Success Story

What counts as evidence in global health? What happens when evidence is contested? This article concentrates on the ‘Worm Wars’, a public academic debate in 2015 on the effectiveness of health interventions to treat populations with parasitic worms, to assess how health interventions are appraised by different disciplinary perspectives. I discuss what happens when a success story about randomised control trials (or RCTs) – often hailed as the ‘gold standard’ of evidence adjudication – is contested but left unresolved. Questioning the prominence of RCTs through the unravelling of this evidence success story offers insights into how these forms of measurement are utilised in practice, first in the medical field and then more widely in economic development and global health policy. I address what a gold standard is within a hierarchy of evidence, as well as the standards that are imbued into RCTs by different disciplinary researchers, and the evidence requirements for health interventions in determining the impact of deworming medication. With the Worm Wars, I show how important measurement standards have become in defining and advocating for global health problems and what this means for the production of evidence.