Clinimetric properties of a translated and culturally adapted Norwegian version of the Patient and Observer Scar Assessment Scale for use in clinical practice and research

Abstract Purpose To translate and culturally adapt the Patient and Observer Scar Assessment Scale, POSAS, to Norwegian and explore its test-retest, intra- and inter-tester reliability. Methods POSAS was translated into Norwegian following international guidelines in collaboration with an international translation bureau. Twenty-six adults and 24 children were recruited from a burns outpatient clinic. Three observer-categories: doctor, nurse and physiotherapist, assessed the patients’ scars and scored the Observer scale for estimating inter-tester reliability. Photos of the scars were taken and used to score the Observer scale a second time for examining intra-tester reliability. The patients or parents/next of kin rated their scars on the Patient scale at the clinic and after two days at home for examining test-retest reliability. Intraclass correlation (ICC) and Kappa were used for statistical analysis. Results A Norwegian version of POSAS (POSAS-NV) was developed. Inter-tester ICC of the Observer parameters varied between 0.203 and 0.728, and for the total sum score, ICC = 0.528(0.280-0.708). Intra-tester ICC of the Observer scale ranged between 0.575 and 0.858. The Patient scale demonstrated high test-retest reliability. Conclusions Intra-tester reliability of the Observer scale and test-retest reliability of the Patient scale of POSAS-NV were found satisfactory, but not inter-tester reliability of the Observer scale.