Checking the Validity and Reliability of the Delirium-O-Meter Questionnaire in the Persian Language

Abstract

Objective: Compiling and designing short and practical psychometric tools are among the benefits and strengths of a good standard test. The Delirium-O-Meter questionnaire measures patients' delirium status. Accordingly, the main aim of this research was to check the reliability and validity of the Persian version of this questionnaire. Method: This exploratory psychometric study was conducted from 2021 to 2022 at the therapeutic research training centers of Tabriz University of Medical Sciences. The study population included patients diagnosed with delirium. Content and construct validity were assessed using exploratory factor analysis and confirmatory factor analysis. Exploratory factor analysis was performed using SPSS 18, which helped identify the underlying factor structure, while confirmatory factor analysis in Smart PLS was employed to confirm the structure's fit. Pearson correlation was used to evaluate the consistency between different raters, and Cronbach's alpha was calculated to assess internal consistency. These methods were selected for their robustness in evaluating the instrument's psychometric properties, ensuring the reliability and validity of the Persian version of the Delirium-O-Meter questionnaire. Results: The Persian version of the Delirium-O-Meter questionnaire, consisting of 11 items, demonstrated strong psychometric properties. The average impact factor was 3.24, indicating a high relevance of the items. The content validity ratio was 0.78, and the content validity index was 0.87, both above the acceptable thresholds, confirming the content validity of the questionnaire. Cronbach's alpha coefficient for the entire questionnaire was 0.77, reflecting good internal consistency. The Kaiser-Meyer-Olkin index was 0.88, and Bartlett's sphericity test was significant (χ² = 278.45, P < 0.001), indicating the appropriateness of the data for factor analysis. Exploratory factor analysis revealed two factors that explained 76.09% of the total variance, supporting the questionnaire's construct validity. Additionally, Pearson’s correlation coefficient between the assessments of two nurses was 0.91, signifying inter-rater solid reliability. Conclusion: The Persian version of the Delirium-O-Meter questionnaire demonstrates acceptable reliability and validity, as confirmed by the comprehensive psychometric evaluation conducted in this study. The strong internal consistency, significant content and construct validity, and high inter-rater reliability underscore its effectiveness in assessing delirium in Persian-speaking patients. These findings highlight the questionnaire's suitability for clinical use, providing a reliable and valid instrument for accurately diagnosing and managing delirium in diverse healthcare settings.