BACKGROUND: Keloid, a fibroproliferative skin disorder, requires accurate scar assessment. Comprehensive evaluation using a standardized instrument from both patient and observer perspectives is essential to capture its multidimensional impact. This study aimed to translate, culturally adapt, and validate the generic patient and observer scar assessment scale (POSAS) 3.0 into Indonesian for keloid assessment. METHODS: A cross-sectional design was adopted following the translation and cultural adaptation guidelines. The instrument was translated into Indonesian by certified translators and administered to 68 keloid patients and 62 dermatologists especially recruited from Pekanbaru and the surrounding areas. Content validity was assessed using the scale-level content validity index average (S-CVI/Ave), construct validity through exploratory factor analysis (EFA), internal consistency with Cronbach’s alpha, test-retest reliability using the intraclass correlation coefficient (ICC), and external validity by correlating the observer scar assessment scale (OSAS) with the modified Vancouver scar scale (mVSS). RESULTS : The Indonesian version of the generic POSAS 3.0 demonstrated strong psychometric properties. The S-CVI/Ave was 0.97. The EFA revealed 3 factors for the patient scar assessment scale and two for the OSAS, explaining 71.25% and 73.1% of the variance, respectively. Cronbach’s alpha was 0.79–0.90 and ICC was ≥0.83. External validity was confirmed by a strong correlation with the mVSS (Spearman’s rho = 0.82, p<0.001). CONCLUSIONS The Indonesian adaptation of the POSAS 3.0 is a valid and reliable tool for comprehensive keloid scar assessment. Future research should explore the responsiveness to therapeutic interventions.
Indonesia ; keloid ; psychometrics ; reproducibility of results ; validation study