Background: Misinformation poses a serious challenge to clinical and policy decision-making in the health field, which relies on accurate and reliable information. The COVID-19 pandemic amplified interest in misinformation and related terms and witnessed a proliferation of definitions.

Objectives: We aim to assess definitions of misinformation and related terms used in health-related literature.

Methods: We conducted a scoping review of systematic reviews that addressed misinformation in the field of health and reported on at least one definition for misinformation or related terms. We searched Ovid Medline, EMBASE, Cochrane, and Epistemonikos databases for reviews published within the last 5 years. We identified definition concepts and analyzed their use across misinformation-related terms.

Results: We included 25 eligible systematic reviews, which contained 48 definitions for misinformation and related terms (13 for misinformation, 12 for disinformation, 15 for infodemic, 7 for fake news, and 1 for malinformation). Out of all the definitions, 34 (71%) were referenced from other sources. We mapped the different terms against the concepts of inaccuracy, intentionality, and being misleading. The definitions were largely consistent, but we did not identify any guidance on operationalizing the concepts addressed in those definitions.

Conclusions: This scoping review of the health literature identified several definitions for misinformation and related terms that were largely consistent but not operationalized. Additional research is needed to operationalize the definitions of misinformation and related terms.

Patient, public and/or healthcare consumer involvement: No patients or members of the public were involved in the current scoping review.