Evaluating the psychometric properties of the fatigue severity scale using item response theory.

BACKGROUND: Fatigue is a common daily experience and a symptom of various disorders. While scholars have discussed the use of the Fatigue Severity Scale (FSS) using item response theory (IRT), the characteristics of the Japanese version are not yet examined. This study evaluated the psychometric properties of the FSS using IRT and assessed its reliability and concurrent validity with a general sample in Japan. METHODS AND MEASURES: A total of 1,007 Japanese individuals participated in an online survey, with 692 of them providing valid data. Of these, 125 participants partook in a re-test after approximately 18 days and had their longitudinal data analyzed. In addition, the graded response model (GRM) was used to assess the FSS items' characteristics. RESULTS: The GRM's results recommended using seven items and a 6-point scale. The FSS's reliability was acceptable. Furthermore, the validity was adequate from the results of correlation and regression analyses. The synchronous effects models demonstrated that the Multidimensional Fatigue Inventory (MFI) enhanced depression, and depression enhanced FSS. CONCLUSION: This study suggested that the Japanese version of the FSS should be a 7-item scale with a 6-point response scale. Further investigations may reveal the different aspects of fatigue assessed by the analyzed fatigue measures.

Longitudinal validation of the Fear of COVID-19 Scale in a nationwide United States sample: An item response theory model across three inflection points of the pandemic.

The COVID-19 pandemic's global emergence/spread caused widespread fear. Measurement/tracking of COVID-19 fear could facilitate remediation. Despite the Fear of COVID-19 Scale (FCV-19S)'s validation in multiple languages/countries, nationwide United States (U.S.) studies are scarce. Cross-sectional classical test theory-based validation studies predominate. Our longitudinal study sampled respondents to a 3-wave, nationwide, online survey. We calibrated the FCV-19S using a unidimensional graded response model. Item/scale monotonicity, discrimination, informativeness, goodness-of-fit, criterion validity, internal consistency, and test-retest reliability were assessed. Items 7, 6, and 3 consistently displayed very high discrimination. Other items had moderate-to-high discrimination. Items 3, 6, and 7 were most (items 1 and 5 the least) informative. [Correction added on 18 May 2023, after first online publication: In the preceding sentence, the term 'items one-fifth least' has been changed to 'items 1 and 5 the least'.] Item scalability was 0.62-0.69; full-scale scalability 0.65-0.67. Ordinal reliability coefficient was 0.94; test-retest intraclass correlation coefficient 0.84. Positive correlations with posttraumatic stress/anxiety/depression, and negative correlations with emotional stability/resilience supported convergent/divergent validity. The FCV-19S validly/reliably captures temporal variation in COVID-19 fear across the U.S.

Psychometric validity and reliability of the 10- and 2-item Connor-Davidson resilience scales among a national sample of Americans responding to the Covid-19 pandemic: an item response theory analysis.

PURPOSE: Psychometric validity/reliability of 10-item and 2-item abbreviations of the Connor-Davidson Resilience Scale (CD-RISC-10; CD-RISC-2) was investigated via item response theory and classic approaches. METHODS: We sampled 5023 adult American participants in a June/July 2020 survey on the COVID-19 pandemic's psychological effects. Our questionnaire incorporated the CD-RISC-10 with other validated measures. CD-RISC-10 items were ranked on item-to-scale correlations, loadings on a one-factor confirmatory factor analysis model, and item slope/threshold parameters plus information curves from a unidimensional graded response model. Concurrent validity of the highest ranked item pair was evaluated vis-à-vis the CD-RISC-10 and CD-RISC-2. Internal consistency, based on average variance extracted (AVE) and multiple reliability coefficients, was also compared. Convergent/divergent validity was tested by correlating anxiety, depression, fear of COVID-19, anxiety sensitivity, coping, and personality measures with both scales and the highest ranked item pair. Binary agreement/classification indexes assessed inter-rater reliability. RESULTS: Items 2 and 9 from CD-RISC-10 ranked the highest. Reliability coefficients were > 0.93, > 0.72, and > 0.82 for the CD-RISC-10, CD-RISC-2, vs summation of items 2 and 9. AVEs were 0.66, 0.67, and 0.77. CD-RISC abbreviations and the summation of items 2 and 9 correlated negatively with anxiety (> - 0.43), depression (> - 0.42), and fear of COVID-19 (> - 0.34); positively with emotional stability (> 0.53) and conscientiousness (> 0.40). Compared to the CD-RISC-2, summative scores of items 2 and 9 more efficiently classified/discriminated high resilience on the CD-RISC-10. CONCLUSION: We confirmed construct validity/reliability of copyrighted CD-RISC abbreviations. The CD-RISC-10's items 2 and 9 were psychometrically more salient than the CD-RISC-2.

Fear of COVID-19 in Romania: Validation of the Romanian Version of the Fear of COVID-19 Scale Using Graded Response Model Analysis.

One of the basic emotions generated by the COVID-19 pandemic is the fear of contacting this disease. The main aim of this study was to examine the psychometric properties of the Romanian version of the Fear of COVID-19 Scale (FCV-19S), based on classical test theory and item response theory, namely, graded response model. The FCV-19S was translated into Romanian following a forward-backward translation procedure. The reliability and validity of the instrument were assessed in a sample of 809 adults (34.6% males; M age = 32.61; SD ±11.25; age range from 18 to 68 years). Results showed that the Romanian FCV-19S had very good internal consistency (Cronbach's alpha = .88; McDonald's omega = .89; composite reliability = .89). The confirmatory factor analysis for one-factor FCV-19S based on the maximum likelihood estimation method with Satorra-Bentler correction for non-normality proved that the model fitted well (CFI = .99, TLI = .97, RMSEA = .06, 90% CI [.05, .09], SRMR = .01). As for criterion-related validity, the fear of COVID-19 score correlated with depression (r = .25, p < .01), stress (r = .45, p < .01), resilience (r = - .22, p < .01) and happiness (r = -.33, p < .01). The heterotrait-monotrait criteria less than .85 certified the discriminant validity of the FCV-19S-RO. The GRM analysis highlighted robust psychometric properties of the scale and measurement invariance across gender. These findings emphasized validity for the use of Romanian version of FCV-19S and expanding the existing body of research on the fear of COVID-19. Overall, the current research contributes to the literature not only by validating the FCV-19S-RO but also by considering the positive psychology approach in the study of fear of COVID-19, emphasizing a negative relationship among resilience, happiness and fear in the context of the COVID-19 pandemic.