Purpose: To evaluate the psychometric properties of the Patient-Reported Outcomes Measurement Information
System (PROMIS) self-efficacy for managing symptoms of the version 1.0 item bank in Korea.
Methods: This study consisted of two phases: first, developing the Korean version of the item bank
following the translation guidelines; and second, performing a cross-sectional study to evaluate its
psychometric properties using the item response theory. This study enrolled 323 patients with type 2
diabetes mellitus between July and August 2020. Cronbach's a was used to assess the reliability of this
item bank. Confirmatory factor analysis, using diagonally weighted least squares, was used to identify the
assumptions of item response theory. Item parameter estimates including discrimination and thresholds
were derived using the graded response model of the item response theory to reflect patient-reported
outcomes as individualized responses.
Results: The Korean version of the item bank demonstrated good reliability (Cronbach's a ¼ .98) and its
discrimination ranged from 1.82 to 4.93. The thresholds resulted in the establishment of a category
response curve for each item. However, no overlap was observed among the category curves. Moreover,
the differential item functioning was not significant for age, gender, and income variables.
Conclusion: The graded response model and differential item functioning provided qualitative evidence
that demonstrated acceptable psychometric properties of symptom management self-efficacy among
patients. This item bank is expected to provide adequate assessments of self-efficacy of symptom
management for patients with a chronic disease, which can contribute to nursing research and
intervention.