Abstract
PurposeThe aims of this cross-sectional study were to explore reliability and validity of the Norwegian version of the Patient-Reported Outcome Measurement System®—Profile 57 (PROMIS-57) questionnaire in a general population sample, n = 408, and to examine Item Response properties and factor structure.MethodsReliability measures were obtained from factor analysis and item response theory (IRT) methods. Correlations between PROMIS-57 and RAND-36-item health survey (RAND36) were examined for concurrent and discriminant validity. Factor structure and IRT assumptions were examined with factor analysis methods. IRT Item and model fit and graphic plots were inspected, and differential item functioning (DIF) for language, age, gender, and education level were examined.ResultsPROMIS-57 demonstrated excellent reliability and satisfactory concurrent and discriminant validity. Factor structure of seven domains was supported. IRT assumptions were met for unidimensionality, local independence, monotonicity, and invariance with no DIF of consequence for language or age groups. Estimated common variance (ECV) per domain and confirmatory factor analysis (CFA) model fit supported unidimensionality for all seven domains. The GRM IRT Model demonstrates acceptable model fit.ConclusionsThe psychometric properties and factor structure of Norwegian PROMIS-57 were satisfactory. Hence, the 57-item questionnaire along with PROMIS-29, and the corresponding 8 and 4 item short forms for physical function, anxiety, depression, fatigue, sleep disturbance, social participation ability and pain interference, are considered suitable for use in research and clinical care in Norwegian populations. Further studies on longitudinal reliability and sensitivity in patient populations and for Norwegian item calibration and/or reference scores are needed.
Highlights
Patient-reported outcomes measurement (PROM) based on standardized questionnaires have become essential tools for health research and patient-centered care
Responses to PatientReported Outcomes Measurement Information System® (PROMIS)-57 were complete for every item, and all response categories were endorsed in each domain, category “5” has only < 10 respondents in five of the DEP and three ANX items. (Histograms of all domain scores are presented in the supplementary online appendix figure S1.)
Both the 4and 8-item short forms were reliable within a range of the theta that is relevant to health measurement, from about one standard deviation (SD) better than the population average to at about two SD worse
Summary
Patient-reported outcomes measurement (PROM) based on standardized questionnaires have become essential tools for health research and patient-centered care. PROMIS item banks were developed via factor analysis and item response theory (IRT) [2, 3] This measurement system encompasses several hundred items across many item banks, each covering a different physical, mental, or social health domain [2], as well as fixed short forms, and profiles such as PROMIS-57 and PROMIS-29. These PROMIS profiles have been described and validated in previous studies [1, 4,5,6,7]. The short forms embedded in PROMIS-57 were hypothesized to have strong internal consistency, a strong concurrent and discriminant validity against RAND36, satisfactory IRT properties, factor structure confirmed, no differential item functioning (DIF) for language, age, gender, education level, or self-reported health
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
