Structural validity and test-retest reliability of the Patient Reported Inventory of Self-Management of Chronic Conditions (PRISM-CC) in a Swedish population of seventy-year-olds with long-term health conditions.

Background: Self-management is internationally recognized as important to maintain independence, quality of life and to minimize the risk of poor health outcomes, especially among persons with multi-morbidity. Self-management can be especially challenging for older adults, who have higher rates of multi-morbidity and experience diverse impacts of long-term health conditions on everyday life. Good measures of self-management are currently lacking. The Patient Reported Inventory of Self-Management of Chronic Conditions (PRISM-CC) is a new, generic, multidimensional measure of self-perceived ease or difficulty with self-management, that overcomes many of the limitations of existing measures.

Objectives: To test the structural validity and test-retest reliability of the Swedish version of the PRISM-CC among seventy-year-olds with long-term health conditions.

Methods: Translation of PRISM-CC items into Swedish followed the Patient-Reported Outcome (PRO) Consortium process. Survey data (n = 516 Swedish seventy-year-olds with ≥1 long-term health condition) was used to assess structural validity of the 36-item PRISM-CC using multidimensional item response theory (IRT) models. Test-retest reliability was assessed on a subsample of 58 individuals using intra-class correlation coefficient (ICC) and Bland-Altman Plots.

Results: The Swedish PRISM-CC demonstrated good internal consistency with Cronbach's alpha >0.8 for all domains, and good fit to a graded response IRT model (RMSEA 0.034, SRMSR 0.050, CFI 0.952 and TLI 0.945). All 36 items had standardized loadings >0.7. ICC showed moderate to good test-retest reliability for all seven domains. The Bland-Altman plots showed minimal bias and good test-retest agreement for all domains.

Conclusion: The Swedish PRISM-CC showed good structural validity and test-retest reliability in this sample of relatively healthy seventy-year-olds with long-term health condition(s). Further validation in a population with more severe health issues is needed.