Measuring resilience after spinal cord injury: Development, validation and psychometric characteristics of the SCI-QOL Resilience item bank and short form

Abstract

OBJECTIVE: To describe the development and psychometric properties of the Spinal Cord Injury--Quality of Life (SCI-QOL) Resilience item bank and short form. DESIGN: Using a mixed-methods design, we developed and tested a resilience item bank through the use of focus groups with individuals with SCI and clinicians with expertise in SCI, cognitive interviews, and item-response theory based analytic approaches, including tests of model fit and differential item functioning (DIF). SETTING: We tested a 32-item pool at several medical institutions across the United States, including the University of Michigan, Kessler Foundation, the Rehabilitation Institute of Chicago, the University of Washington, Craig Hospital and the James J. Peters/Bronx Department of Veterans Affairs medical center. PARTICIPANTS: A total of 717 individuals with SCI completed the Resilience items. RESULTS: A unidimensional model was observed (CFI=0.968; RMSEA=0.074) and measurement precision was good (theta range between -3.1 and 0.9). Ten items were flagged for DIF, however, after examination of effect sizes we found this to be negligible with little practical impact on score estimates. The final calibrated item bank resulted in 21 retained items. CONCLUSION: This study indicates that the SCI-QOL Resilience item bank represents a psychometrically robust measurement tool. Short form items are also suggested and computer adaptive tests are available.