Background and aims: Although many models exist for designing knowledge translation interventions aimed at supporting evidence – based policy-making, no valid, reliable and domesticized measuring tool exists for assessing the changes taking place in utilization of research evidence by policy-makers and stakeholders. The goal of this study was to design and validate one such tool based on the Theory of Planned Behavior (TPB). This tool can then be applied to determine the status quo, design interventions and assess their impact.

Methods: The study population consisted of all the technical units and their employees in the five deputies of the Ministry of Health and Medical Education in 2013. All those eligible to participate were included in the study, which comprised 373 persons. The reliability of the tool was determined through test-retest; its internal consistency and composite construct reliability and validity were determined by face, content, divergent, convergent, discriminant and construct validities. SPSS-20 and LISREL-8.8 were employed to analyze the data. To assess the fitness of the measurement models three groups of indices were used, absolute, relative and parsimonious.

Results: The content & face validities of the tool were 83% and 67% respectively. The reliability was tested through internal consistency, where Cronbach's alpha of different constructs ranged from 0.7 to 0.9. In the test-retest method, the intra-class correlation was between 0.75 and 0.87. The composite reliability of all the constructs was higher than the acceptable value. Confirmatory Factor Analysis showed that the penta-factorial structure of the experimental data had acceptable fitness with the TPB (GFI=0.86, NFI=0.94, RSMEA=0.075).

Conclusion: Based on our results, the TPB – based tool has relatively good reliability and validity to assess evidence utilization in health policy-making.