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. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11136-022-03125-y.