Validation of the Spanish version of the palliative care outcome scale

BACKGROUND AND OBJECTIVE: The objective of this study was to translate the Palliative Care Outcome Scale (POS) into Spanish and to validate it. MATERIAL AND METHOD: The translation and adaptation was based on the conceptual equivalence of the terms used. In order to study the psychometric properties, 200 patients receiving palliative care were asked to fill out the POS questionnaire, the European Organization for Research on Cancer Treatment Quality of Life Questionnaire (EORCT QLQ C-30), the Barthel Index and the Karnofsky Index on their first visit. The Spanish version of the POS questionnaire was given to the patients again, a week later, to measure the intra-observer reliability. RESULTS: There were no major problems with the translation and adaptation process. The Spanish POS adapted very well for both the staff and the patients versions. Inter- and intra-observer reliability was good, with intraclass correlation coefficients of between 0.61 and 0.93 according to the item. Internal consistency analysis showed a Cronbach's alpha of 0.62 for the staff version and 0.64 for the patients version. Most of the Spanish POS correlated with the EORTC QLQ C-30 emotional function scale and quality of life scale. CONCLUSIONS: The Spanish POS is a valid and reliable instrument for measuring the quality of life of patients receiving palliative care. It is useful in research as well as in everyday clinical practice.