Abstract
BACKGROUND: Psoriatic disease is a lifelong chronic illness for which there is no cure. It is well established that psoriasis leads to a major impairment of health-related quality-of-life and wellbeing. Most people with psoriasis live together with partners, bringing along a major burden for them. The FamilyPso was created to measure this burden in psoriasis. OBJECTIVE: The aim of the FamilyPso international study was to validate this tool and to show feasibility for the use of the FamilyPso across multiple countries. METHODS: A prospective cohort study was conducted in 11 centers in Austria, Canada, Germany, Italy, Spain, and Turkey. The factor structure of the FamiliyPso was examined by confirmatory factor analysis (CFA) including tests of measurement invariance for gender and language. Subgroups (e.g., countries and gender) were tested for significant differences, and the relationship between the severity of illness and FamilyPso scores was tested for differences between countries using a mixed regression model. Descriptive statistics for items and scores are presented herein. RESULTS: The cohort consisted of 556 people with psoriasis and their partners. Patients agreed that their partners would answer the questionnaire in their absence and return the forms to the centers. The mean age of patients and partners was 51 years. Psoriasis severity was mild in 57.6%, moderate in 31.5%, and severe in 10.9% of cases, and 91.3% received treatment. The results of the CFA confirmed the original factor structure with minor modifications. Self-assessed high severity of psoriasis was a predictor for a higher burden in 4/5 FamilyPso domains. There was an increased burden to partners related to the severity of psoriasis particularly in the domain "general emotional strain," including items such as a "feeling of helplessness." The results of the study showed that the FamilyPso could assess the burden of partners of people with psoriasis and can be used across different countries. CONCLUSIONS: The data can improve management of psoriatic disease and should be considered in shared decision-making.