Validity and reliability of the Amharic version of EORTC QLQ-OG25 among esophagogastric cancer patients in Ethiopia

Abstract

Background: Cancers of the stomach and esophagus are the fourth and sixth most common causes of cancer-related deaths worldwide, respectively. Although various tools have been developed to assess the quality of life of patients with esophagogastric cancer, EORTC QLQ- C30 and EORTC QLQ- OG25 are the most used all over the world. However, they have not been validated in an Ethiopian context. Therefore, this study aimed to evaluate the psychometric properties of EORTC QLQ- OG25 among Ethiopian patients with esophageal and gastric cancer. Methods: EORTC QLQ- OG25 is a 25-item tool with 10 single items and six symptom scales: Eating restrictions, reflux, dyspha- gia, odynophagia, discomfort and pain, and anxiety. The tool was translated into Amharic according to the EORTC forward- backward translation protocol. To check its validity and reliability, a cross-sectional study among 158 patients was conducted from March to May 2020 at Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia. The psychometric properties of EORTC QLQ- C30 and EORTC QLQ- OG25 were assessed using multitrait scale analysis, known group validity, convergent validity, and divergent validity. Internal consistency was examined with Cronbach's alpha. Result: Eighty-three (52.5%) of the participants were men; the median age was 50 years (IQR = 18 years). The overall item corre- lation alpha values ranged between 0.39 and 0.7. All item correlations within their scales were greater than 0.4. The correlation coefficients between all items and their own domain were greater than for other domains. The esophagogastric and core ques- tionnaire correlation ranged from −0.65 to 0.62. The tool showed a significant difference between patients with good physical function and those with impaired physical function. Conclusions: The findings suggest that the Amharic version of EORTC QLQ- OG25 is a valid and reliable tool among patients from Ethiopia with esophagus and gastric cancer. Therefore, we recommend that researchers and clinicians use the core tool together with the specific tool.