Self-report measures of body dysmorphic disorder and their psychometric properties: A systematic review using COSMIN methodology

Background: Body dysmorphic disorder (BDD) affects approximately 2% of the general population but often goes undetected and undiagnosed. Valid and reliable measures for assessing BDD are crucial to improve detection and facilitate clinical decision-making. This review is the first to synthesise and critically appraise existing self-report measures of BDD symptom severity. // Method: PubMed, EMBASE, MEDLINE®, and PsycINFO databases were systematically searched for studies developing and/or evaluating the psychometric properties of self-report BDD symptom severity measures. The COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN; Prinsen et al., 2018) framework was used to evaluate psychometric properties and assess the methodological quality of studies. // Results: Forty-two studies were eligible for inclusion, evaluating 16 self-report measures and four short-form versions. Ten achieved the second highest level of recommendation, demonstrating reasonable evidence for multiple psychometric properties, such as internal consistency and convergent validity. There was variability in the range of psychometric properties explored, with few studies examining cross-cultural validity/measurement invariance or measure error. According to the stringent criteria, much of the evidence was rated low or very low quality. Notably, this was mostly due to a lack of evaluation in BDD samples, rather than measures performing poorly. // Conclusions: A number of self-report questionnaires show promise as valid and reliable tools to assess BDD symptoms. To generate higher quality evidence for their psychometric properties, future research should apply COSMIN recommended methodology, including evaluating measures in individuals with BDD, and assessing under-researched properties such as cross-cultural validity.