Validity and Reliability Assessment of the Persian Version of a EORTC QLQ‐STO22 Questionnaire for Patients With Gastric Cancer Who Underwent Total Gastrectomy

ABSTRACT Background and Aims The EORTC QLQ‐STO22 is a widely validated instrument for assessing health‐related quality of life in patients with gastric cancer. Given the high prevalence of gastric cancer and its specific risk factors in Iran, validating this tool for the Iranian population is essential. This study aimed to evaluate the validity and reliability of the Persian‐translated EORTC QLQ‐STO22. Methods This study assessed the content validity and reliability of a Persian translation of the 22‐item quality of life questionnaire (EORTC QLQ‐STO22) designed for patients with gastric adenocarcinoma post‐total gastrectomy. Content validity was evaluated by an expert panel using the Content Validity Ratio (CVR), as a result, 20 of the original 22 items were included in final version following panel review. Reliability was assessed through intraclass correlation coefficients (ICC) and Cohen's Kappa. Construct validity was examined by correlating questionnaire scores with clinical variables such as age, tumor size, and T stage. Statistical analyses were performed using R software. Results The study included 99 patients with a mean age of 60.1 years and 18.2% female. Content validity assessment by expert panel retained 20 of the original 22 items. Reliability analysis demonstrated excellent test‐retest consistency, with mean ICC of 0.999 and several items showing perfect agreement. Cohen's Kappa indicated strong to perfect agreement for most items, though two items showed lower consistency. Construct validity was supported by significant correlations between questionnaire scores and clinical variables, including a moderate positive correlation with age. Patient responses highlighted key quality of life challenges post‐gastrectomy, particularly concerns about health and future, weight issues, difficulty eating solid foods, and early satiety. Conclusion The findings of this study confirm that the Persian version of the EORTC QLQ‐STO22 is a valid and reliable instrument for assessing quality of life in Iranian patients following total gastrectomy for gastric cancer.