Last update:
16-Mar-2026

OBJECTIVE To analyze the validity and reliability of the adapted version of the Online Misinformation Susceptibility Scale (OMISS) for health-related misinformation.

METHOD We examined the reliability of the Health-Related Online Misinformation Susceptibility Scale (HR-OMISS) by calculating Cronbach's alpha and McDonald's omega. Construct validity of the HR-OMISS was evaluated by performing confirmatory factor analysis, as well as the Trust in Scientists Scale, the single-item scientists' confidence scale, the Conspiracy Mentality Questionnaire (CMQ), and the single item conspiracy belief. Known-groups validity of the HR-OMISS was tested by comparing healthcare workers with a Master of Science (MSc) diploma versus those without one.

RESULTS The HR-OMISS demonstrated very good reliability, since Cronbach's coefficient alpha 0.920 and McDonald's omega was 0.922. The adapted version of the OMISS for health-related misinformation (HR-OMISS) was found to have a one-factor structure as the original version (OMISS). Concurrent validity of the HR-OMISS was very good since a statistically significant negative correlation was found between the HR-OMISS and the Trust in Scientists Scale (r=-0.330, p<0.001), and the single-item scientists confidence scale (r=-0.258, p<0.001). Moreover, a positive correlation was observed between the HR-OMISS and the CMQ (r=0.118, p=0.072) and the single item conspiracy belief (r=0.074, p=0.260). The HR-OMISS showed known-groups validity since the mean score for healthcare workers with a MSc diploma (25.6) was lower than those without a MSc diploma (29.6) (p=0.002).

CONCLUSIONS The HR-OMISS is a valid and reliable tool to measure levels of health-related online misinformation susceptibility.

Key words: Conspiracy theories, Fake news, Misinformation, Online Misinformation, Susceptibility Scale, Scientists, Trust.