Psychometric Analysis of a Persian Version of the EuropeanOrganization for Research and Treatment of Cancer OG25 Quality of Life Questionnaire in Oesophagogastric Cancer Patients

Background: Health-related quality of life (HRQL) is a fundamental outcome in oncology patients and qualityof life (QOL) assessment requires clinically relevant questionnaires. The purpose of this study was translationand definition of measurement properties and the clinical validity of Quality of Life Questionnaire (QLQ) -OG25module in Persian patients with oesophagus, oesophagogastric junction (OGJ) or gastric cancers. Materials and
Methods: The translation procedure followed European Organization for Research and Treatment of Cancer(EORTC) guidelines. Both EORTC QLQ-OG25 and a core questionnaire (EORTC QLQ-C30) were administeredto patients with oesophagus (150), OG junction (93) and gastric (32) cancer undergoing multi-modal treatments.Convergent and discriminant validity, Cronbach’s alpha coefficient and known-groups comparisons were used toexamine reliability and validity.
Results: In all, 275 patients (mean age 62 years) completed both questionnaires.Compliance rate was high and the questionnaire module was well accepted. We found good reliability for multiitemsubscales of QLQ-OG25 (Cronbach’s alpha coefficients 0.76-0.89). About 73% had TNM staging and scalesdistinguished between clinically distinct groups of patients. However, patients in palliative group experiencedcompromised functional status and worse treatment-associated symptoms than those in the potentially curativegroup. Test-retest scores were consistent. Multi-trait scaling analysis demonstrated good convergent anddiscriminant validity.
Conclusions: Overall, the Persian version of QLQ-OG25 demonstrated psychometricand clinical validity that supports its application as a supplement to the original tool (EORTC QLQ-C30) whenassessing HRQL in patients with upper-gastrointestinal (GI) cancer both in curative and palliative phases.