Assessing counselor competence in working with gender nonconforming clients: A randomized study.

Trust in public health authorities is a foundational component of public health governance, shaping the capacity of institutions to communicate risk, implement policy, and coordinate collective action [–]. Because public health authorities operate primarily through guidance, regulation, and interventions, their effectiveness depends not only on technical capacity but also on public confidence in their intent and legitimacy. When trust is present, public health institutions are better positioned to function as credible stewards of population health [,]; when it is absent, even well-designed interventions may fail to achieve their intended impact [–]. Despite its importance, trust in public health authorities has been measured inconsistently across studies [,]. Quantitative surveys often rely on single or unvalidated items, and even validated tools differ in their focus on specific authorities, trust dimensions, or phrasing, limiting their comparability [–]. The Trust in Public Health Authorities (TiPHA) Scale, developed by Holroyd and colleagues (2021), advanced the field by offering a psychometrically validated instrument capturing two dimensions of trust: beneficence and competence []. Initial validation of the TiPHA Scale relied on confirmatory factor analysis to establish its dimensional structure and internal consistency, providing a useful first step in scale development but offering limited insight into item-level measurement properties []. A key challenge in trust research is that it is a latent construct, meaning it cannot be directly measured and must be estimated before it can inform empirical studies or practical applications. Item Response Theory (IRT) offers a sophisticated framework for modeling such latent traits at the item level, providing more theoretically grounded and detailed measurement than traditional approaches such as factor analysis [,]. IRT has long been applied in psychological and educational testing [], but its use has since expanded. Recent applications include health measurement more broadly [,], clinical assessment [], and even scales for environmental risk perception []. This broader use demonstrates the adaptability of IRT in capturing attitudes, perceptions, and other constructs that, like trust, cannot be directly observed.