Abstract
Background & Objectives: One of the most common psychological problems in children is anxiety disorders, which cause significant psychological pathology. Since anxiety is associated with significant functional impairment in people with anxiety disorders, identifying the factors that play a key role in anxiety disorders will increase the existing knowledge in preventing and treating anxiety disorder. Recent cognitive models of adult anxiety disorders have increasingly highlighted the role of negative beliefs about uncertainty, and it has been suggested that intolerance of uncertainty may be a causal risk factor in the development of pathological anxiety and worry. To prevent and treat anxiety, we need reliable tools to identify the effective factors in creating and maintaining pathological anxiety. Therefore, the present study was conducted to investigate the psychometric characteristics of the A index of children's intolerance of uncertainty.
Methods: The present psychometric study is descriptive correlational. The statistical population included all students aged 10 to 13 years of primary schools in Kermanshah City, Iran, in the academic year 2021-2022. The cluster random sampling method was used to select the samples. In this study, 500 people were selected as a sample and answered Multidimensional Anxiety Scale for Children (March et al., 1997), Intolerance of Uncertainty Index-A for Children (Rifkin & Kendall, 2020), and Conners' Parent Rating Scale-Revised Short Form (Conners, 1997). To investigate the psychometric characteristics of intolerance of uncertainty index-A for children, the English text was translated into Farsi by an English language expert and a psychologist. Then the Persian version prepared by another English language expert was translated into English, and finally, under the supervision of a Psychologist, the discrepancies were resolved and the final version was prepared. The qualitative method was used to check the face validity of the Intolerance of Uncertainty Index-A for Children. Also, to quantitatively evaluate content validity and to ensure that the most important and correct content is selected, the content validity ratio was used, and to ensure that the questions of Intolerance of Uncertainty Index-A for Children were designed in the best way to measure the content, the content validity index was used. To assess the convergent validity of Intolerance of Uncertainty Index-A for Children, the correlation of this questionnaire with the Multidimensional Anxiety Scale for Children and the divergent validity of Intolerance of Uncertainty Index-A for Children with Conners' Parent Rating Scale-Revised Short Form were investigated. Also, to evaluate the retest reliability of the questionnaire, 126 of the participants completed the questionnaire again after two weeks of the initial implementation of the Intolerance of Uncertainty Index-A for Children. SPSS version 22 and R version 4.0.2 software were used to analyze the data and examine the psychometric properties of the children's Intolerance of uncertainty scale, the Persian version.
Results: The results showed that Intolerance of Uncertainty Index-A for Children had good reliability and the Cronbach α coefficient of the questionnaire was equal to 0.92. Also, the correlation results between the two implementations of this index within two weeks ranged from 0.53 to 0.77, which indicated its appropriate retest reliability. The correlation of the A index with the Multidimensional Anxiety Scale for Children was positive and significant (p<0.01, r=0.46). However, there was no significant correlation with the Connors Parent Rating Scale which indicated appropriate convergent and divergent validity for the Intolerance of Uncertainty Index-A for Children, respectively. The results of examining the fit indices of the measurement model (CMIN/DF=2.99, IFI=0.919, CFI=0.919, TLI=0.905, AGFI=0.921, GFI=0.90, RMSEA=0.06), indicated the appropriate fit of the model with the data of Intolerance of Uncertainty Index-A for Children.
 Conclusion: The Persian version of the Intolerance of Uncertainty Index-A for Children has favorable psychometric properties, and this tool can be used to assess the level of intolerance of uncertainty in children.