Positive deviance in health and medical research on individual level outcomes - a review of methodology.

BACKGROUND: Positive deviance as a methodology is increasing in application yet there is high variability in how this approach is applied in health services research.
METHODS: We conducted a scoping review of the literature for positive deviance applied to health outcomes informed by PRISMA-ScR. We searched the literature from 1945 to 2020, including articles on positive deviance or positive outliers, and restricted to examining individual rather than organizational outcomes. We analyzed the methodology applied including the process of identifying deviants, the use of control groups, and the degree of community engagement.
RESULTS: Our initial search identified 1140 manuscripts; we included 104 papers describing 98 studies, 11 topical and one miscellaneous category. Most studies used objective measures of health or survey-based responses to identify deviants from a sub-set of the population at risk. The use of controls was less common in some topics (hospital infections), whereas controls were universally applied in other topics (malnutrition). The degree of community engagement varied widely.
CONCLUSIONS: Positive deviance would benefit from improvements in reporting and standardized approaches to defining deviance. Studies could be improved through clarified definitions of deviance/risk, explicit descriptions of community engagement, and more consistent use of controls.