Linguistic and content validation of the translated and culturally adapted patient-generated subjective global assessment (PG-SGA)

The Patient-Generated Subjective Global Assessment (PG-SGA) is an instrument to screen, assess and monitor malnutrition and risk factors, and to triage for interventions. After having translated and culturally adapted the original PG-SGA for the Italian setting, according to International Society for Pharmacoeconomics and Outcomes Research (ISPOR) Principles, we tested linguistic validity, i.e., perceived comprehensibility and difficulty, and content validity (relevance) of the Italian version of the PG-SGA in patients with cancer and a multidisciplinary sample of healthcare professionals (HCPs). Methods: After the translation and cultural adaptation of the original PG-SGA for the Italian setting, the patient component (i.e., PG-SGA Short Form (SF) was tested for linguistic validity (i.e., comprehensibility ad difficulty) in 120 Italian patients with cancer and 81 Italian HCPs. The full PG-SGA, i.e., patient and professional component of the PG-SGA, was tested for content validity, i.e., relevance, in 81 Italian HCPs. Through item and scale indices we evaluated the comprehensibility (IeCI, SeCI), difficulty (I-DI, S-DI) and content validity (I-CVI, S-CVI). Results: Patients perceived comprehensibility and difficulty of the PG-SGA SF (Boxes) as excellent (SeCI = 0.98, S-DI = 0.96). Professionals perceived comprehensibility of the professional component (Worksheets) as excellent (SeCI = 0.92), difficulty as acceptable (S-DI = 0.85), and content validity of the full PG-SGA as excellent (S-CVI = 0.92). Dietitians gave higher scores (indicating better scores) on comprehensibility, difficulty, and content validity of Worksheet 4 (physical exam) than the other professions. In Worksheet 4, four items were considered most difficult to complete and were considered below acceptable range. Relevance was perceived as excellent by professionals for both the patient component (S-CVI = 0.93) and the professional component (S-CVI = 0.90), resulting in S-CVI = 0.92 for the full PG-SGA. Slight textual modifications were implemented resulting in the final version of the Italian PG-SGA.