Psychometric validation and cross-cultural adaptation of the Integrated Palliative care Outcome Scale in Polish (IPOS-Pol)

Objective The study aimed to assess the reliability and validity of the IPOS-Pol for patient self-reporting. Method Patients (>18 years of age) with advanced cancer admitted to three palliative care centers (inpatient units and home-based) were recruited to a multicenter, cross-sectional, observational, prospective study. Participants provided responses to the IPOS-Pol Patient version and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire - Core 15 - Palliative Care (EORTC QLQ-C15-PAL) Polish version at baseline (T1) and four to seven days later (T2). We assessed test-retest reliability, internal consistency, and construct validity of the tool. Results One hundred and eighty patients were included. Test-retest reliability demonstrated no statistically significant differences in the average outcomes of the IPOS-Pol between T1 and T2 (27.2 +/- 9.2 vs. 26.5 +/- 8.7; p > 0.05). The intra-class correlation coefficient between T1 and T2 was r = 0.83 (p < 0.0001), the intra-class correlation coefficient for test-retest reliability of the IPOS-Pol items ranged from 0.63 to 0.84 (p < 0.0001), and the Cronbach's alpha coefficient for internal consistency was 0.773. The correlation coefficient between the IPOS-Pol and EORTC QLQ-C15-PAL total score was 0.79 (p < 0.001). Significance of results The patient version of the Polish adaptation of IPOS is a valid and reliable outcome measure for assessing symptoms and concerns of individuals receiving palliative care, as well as the quality of care provided.