The HCT Index: A Typology and Index of Health Conspiracy Theories with examples of use

Abstract

Conspiracy theories about secret agendas behind vaccination programmes, the side effects of medical treatments, and cover-ups by the government or pharmaceutical industry are prevalent in many countries, and can have highly detrimental and far-reaching effects on people’s wellbeing. For, research and policy-making in public health, it is therefore vital to understand the nature, construction and dissemination of these health conspiracy theories (HCTs). Inspired by the influential ATU index of folktale types, this paper presents a typology and example index of international HCTs to be used as a tool to enable researchers to identify and categorise HCTs they come across, and to provide a pool of examples of HCTs which could be used in various fields of research. Also presented are two studies which used the HCT Index as a source of material. The first, a survey of HCT exposure and belief in the UK found that both familiarity and belief were high: 97% of Britons are familiar (having heard the same or similar before) with at least one HCT and 49% of Britons believed that at least one HCT was likely to be true. Demographic influences are also discussed. The second study, a focus group discussion health rumours in rural Sri Lanka, found concerns over threats to fertility as well as how to verify information that falls outside of typical experience.

The HCT Index: a typology and index of health conspiracy theories with examples of use

“…A full list of sources is presented in SM.1 in the extended data (Stubbersfield et al, 2021). HCTs were added to the index only if they met at least one of the following eligibility criteria for inclusion as an HCT, viz.…”

“…The '[005]' indicates that this example also features HCT type 005, 'Anti-Vaccine'. See SM.2 for the synopsis and full HCT Index (extended data, Stubbersfield et al, 2021).…”

“…After construction of the HCT Index another search was conducted (September 2016) to assess data saturation of the HCT types and to add new examples. We then made the HCT Index publicly available as a preprint (Stubbersfield et al, 2019) and periodically revised and updated it during that period. Another search was conducted in September 2020 in response to the COVID-19 pandemic and associated conspiracy theories.…”

“…They were also asked to rate the extent to which they agreed with the statement that the presented HCT was "likely to be true" on a Likert scale ranging from 0 (strongly disagree) to 6 (strongly agree). The presentation order of HCTs was randomised to avoid order effects (see SM.3 in the extended data for details of survey content, Stubbersfield et al, 2021). The questionnaire used is a novel questionnaire and has not been previously validated.…”

“…Participants took part in open discussion on the topic of medical and health-related rumours and their attitudes towards them. Topics for discussion were based on the transmission of HCTs and contemporaneous fieldwork in the locale (see SM.5 in the extended data for topic guide, Stubbersfield et al, 2021). The topic guide was not piloted and had not been used previously.…”