Validity and reliability of the integrated palliative care outcome scale (IPOS) in Korea: a multicenter study of terminally ill cancer patients.

Background: The Integrated Palliative care Outcome Scale (IPOS) is a key tool for assessing the quality of palliative care using patient-reported outcomes. This study aimed to culturally adapt and translate the IPOS to Korean and verify its psychometric properties for use in palliative care settings.

Methods: The IPOS was translated and culturally adapted, followed by validation in 119 terminally ill cancer patients and 28 healthcare providers across six Hospice and Palliative Care Units from September 2023 to January 2024. Reliability was assessed using internal consistency, test-retest reliability, and inter-rater reliability. Concurrent validity was assessed using Spearman's correlation coefficients between the IPOS items and the corresponding EORTC QLQ-C15-PAL and the corresponding FACIT-Sp-12.

Results: The Korean IPOS demonstrated good internal consistency, with Cronbach's alphas of 0.74 for patients and 0.81 for staff. The test-retest reliability showed moderate-to-good stability, with an intra-class correlation coefficient of 0.722 for the IPOS total score. Concurrent validity was supported by moderate correlations with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 15 Palliative Care (EORTC QLQ-C15-PAL) and Functional Assessment of Chronic Illness Therapy-Spiritual Well-being Scale (FACIT-Sp-12). Known-group validity was demonstrated by significant differences in the IPOS scores across Phase of Illness.

Conclusion: The Korean IPOS is reliable and valid for assessing palliative care outcomes. This validation supports its use in clinical practice and research and provides a robust framework for evaluating and improving palliative care delivery in Korea.