A Japanese translation, cultural adaptation, and linguistic and content validity confirmation of the Scored Patient-Generated Subjective Global Assessment

Purpose: The Scored Patient-Generated Subjective Global Assessment (PG-SGA©) is a globally recognized and used nutritional screening, assessment, monitoring, and triaging tool. The aim of this study was to translate and culturally adapt the original English PG-SGA for the Japanese speaking populations and to assess its linguistic validity (i.e., comprehensibility, difficulty) and content validity, as perceived by Japanese patients and healthcare professionals. Methods: In accordance with methodology used in previous Dutch, Thai, German, and Norwegian PG-SGA studies, we followed the ten steps of the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) Principles of Good Practice for Translation and Cultural Adaptation for Patient-Reported Outcome Measures. The study enrolled 50 patients and 50 healthcare professionals (HCPs) to evaluate the comprehensibility and difficulty of the translated and culturally adapted PG-SGA. The HCPs also evaluated the content validity of the translation. We evaluated each item and quantified scale indices for content validity (item content validity index (I-CVI), scale content validity index (S-CVI)), comprehensibility (item comprehensibility index (I-CI), scale comprehensibility index (S-CI)), and difficulty (item difficulty index (I-DI), scale difficulty index (S-DI)). Results: Patients evaluated the comprehensibility and difficulty of the patient component as excellent (S-CI = 0.97, S-DI = 0.96). The professionals rated the Japanese version of both components of the PG-SGA as very relevant (S-CVI = 0.94). The professionals evaluated the comprehensibility of the professional component as being acceptable (S-CI = 0.88) but difficult (S-DI = 0.69), based predominantly on items related to physical examination (I-DI = 0.33–0.67). Conclusion: The PG-SGA was systematically translated and culturally adapted for the Japanese setting according to the ISPOR process. The Japanese version of the PG-SGA was perceived as comprehensive, easy to use, and relevant. Perceived difficulty in professional components, specifically in the context of metabolic demand and physical examination, will require appropriate training for professionals in order to optimize implementation.