Over 40 years (1981–2023) assessing stigma with the Community Attitudes to Mental Illness (CAMI) scale: a systematic review of its psychometric properties

BACKGROUND: The Community Attitudes to Mental Illness (CAMI) scale measures social stigma towards people with mental illness. Although it has been used worldwide, the psychometric properties of the CAMI have not been systematically reviewed. The main aim of this study was to systematically review the psychometric properties of the different versions of the CAMI more than 40 years after of its publication. METHODS: A systematic search was conducted in MEDLINE, PsycINFO, Web of Science, and EMBASE from 1981 (year of publication) to 2023 (present). A double review was performed for eligibility, data extraction, and quality assessment. RESULTS: A total of 15 studies enrolling 10,841 participants were included. The most frequently reported factor structure comprises 3 or 4 factors. Overall, the internal consistency seems adequate for the global scale (α ≥ 0.80), except for CAMI-10 (α = 0.69). Internal consistency of the subscales are not supported, with authoritarianism being the weakest factor (α = 0.27 to 0.68). The stability over time of the total scale has been assessed in the CAMI-40, CAMI-BR, and CAMI-10 (r ≥ 0.39). Few studies have assessed the temporal stability of the CAMI subscales. Most of the correlations with potentially related measures are significant and in the expected direction. CONCLUSIONS: The 3 and 4 factor structure are the most widely reported in the different versions of the CAMI. Even though reliability and construct validity are acceptable, further item refinement by international consensus seems warranted more than 40 years after the original publication. SYSTEMATIC REVIEW REGISTRATION: PROSPERO identification number: CRD42018098956. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13643-023-02230-4.