The Korean version of the Symptom Experience Index: A psychometric study

Abstract

Background: Symptom assessment and management are vital aspects of patient care through the entire illness trajectory. Patients often experience two or more symptoms concurrently. Building global assessment capacity on symptoms holds significant promise for advancing the science of nursing. The Symptom Experience Index is a reliable and valid patient-centered health outcome measure developed in the United States to assess multiple symptoms and distress. No Korean version is available for Korean healthcare professionals and patients to promote an accurate assessment of multiple symptoms. Objective: To translate the Symptom Experience Index into Korean language and assess its psychometric properties in Korean patients and healthy adults. Design: A psychometric study with a cross-sectional design. Setting: Two hospitals and a large university in Seoul, Korea in 2009. Participants: A purposive sample of 230 adult participants, including medical-surgical and oncology patients, as well as healthy university students. Methods: The English Symptom Experience Index was translated to Korean language using an integrative translation method to ensure its semantic equivalence and content validity. The Korean version was then pretested and tested using a contrast-group and test-retest method. Results: Semantically, no modifications to items were needed in terms of comparability of language and similarity of interpretability. Feedback on the pretest of the Korean version by 15 Korean adult patients resulted in one item deletion and one item modification. The Korean version demonstrated high internal consistency with the Cronbach's alpha coefficient: total symptom experience of 0.92, occurrence of 0.91 and distress of 0.90. Intra-class correlation coefficients demonstrated strong stability over time: total symptom experience (ICC = 0.82; 95% CI = 0.73-0.88), occurrence (ICC = 0.77; 95% CI = 0.66-0.84), and distress (ICC = 0.85; 95% CI = 0.77-0.89). Construct validity was supported by (1) factor analysis; (2) differences in symptom experience scores between healthy university students and patient groups; and (3) positive correlations between symptom experience scores and functional impairment. Conclusions: Our study provided evidence to support psychometric properties of the Korean Symptom Experience Index. The use of the instrument can help patients who speak Korean language systematically report symptoms and assist healthcare professionals in assessing multiple symptom experience. (C) 2012 Elsevier Ltd. All rights reserved.