Cross-cultural validation of the integrated palliative outcome scale for neurological patients (IPOS-Neuro S8) in multiple sclerosis patients.

Objectives: Standardized measures to evaluate neurological patients in palliative care are missing. The Integrated Palliative Outcome Scale, a self-report tailored for neurological patients (IPOS Neuro-S8) helps identify symptom burden but lacks validation in German. This study aimed to validate the IPOS Neuro-S8 in severely affected multiple sclerosis (MS) patients.

Methods: This validation study is a secondary analysis of data from a clinical phase II intervention study with severely affected MS patients. The original study enrolled German-speaking patients aged 18 with severe MS who receive an escalating immunotherapeutic agent and/or exhibit a high level of disability were recruited from the administrative district Cologne (#DRKS00021783). In this validation study, we evaluated construct, discriminant, and convergent validity, internal consistency, test-retest reliability, and sensitivity to change of the IPOS Neuro-S8, using the "Hamburger Lebensqualitätsmessinstrument" (HALEMS), and the Hospice and Palliative Care Evaluation supplemented by neurological symptoms (HOPE+) as comparison measures.

Results: Data from 80 MS patients (mean age 56, SD = 11) were analyzed. Exploratory and confirmatory factor analyses revealed a 3-factor structure (r = 0.34-0.63), reflecting distinct clinical patterns, i.e., breath-mouth connection, pain-sleep cycle, and nausea-vomiting link. Significant convergent validity to hypothesized total score of the HOPE+ (r_s(78) = 0.71, p < 0.001) and good discriminant validity using the HALEMS total score (r_s(78) = 0.48, p < 0.001) were observed. Correlation with physical symptoms of the HALEMS was stronger than with nonphysical aspects. Internal consistency (Cronbach's α = 0.67) and test-retest reliability (intraclass coefficient = 0.75) were acceptable.

Significance of results: IPOS Neuro-S8 displays promising psychometric properties for assessing palliative care symptoms in severe MS, a model for other severe neurological diseases due to MS's broad central nervous involvement, allowing findings to be transferable to other neurological diseases. A criterion for minimal clinically important difference was established to evaluate the sensitivity to change. Additional validation across different neurological conditions and disease severities is warranted to enhance generalizability and clinical utility.