Evaluating the Validity and Reliability of Persian Version of The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire for Colorectal Cancer (EORTC QLQ-CR29)

The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire for Colorectal Cancer (EORTC QLQ-CR29) is developed to specifically evaluate the quality of life in patients with colorectal cancer. In this study, we aimed to validate the QLQ-CR29 in Iranian patients with Persian language linguistically and to determine its psychometric properties.

This was a linguistic validation study. The QLQ-CR29 was translated by standard forward-backward translation method. After a pilot study with 15 patients, 100 patients with colorectal cancer completed the QLQ-CR29 along with the EORTC QLQ-C30 and the MD Anderson Symptom Inventory (MDASI) and the psychometric properties of the QLQ-CR29 were evaluated.

A hundred of patients with colorectal cancer participated in the main study with the mean age of 60.4 ± 13.4 year; 64% were men. Cronbach’s alpha was 0.89 for the whole QLQ-CR29 and ranged from 0.65 to 0.98 for the subscales. In all the multi-item subscales, the correlation of the item with its corresponding subscale was above 0.4 (r = 0.7 to 0.9). There was a moderate to strong significant correlation between the functional subscales of the QLQ-CR29 and the QLQ-C30 subscales (r = 0.3 to 0.6). In addition, most of the QLQ-CR29 subscales were correlated with MDASI severity and interference subscales (r = 0.2 to 0.5).

According to these results, the psychometric properties of the Persian version of the EORTC QLQ-CR29 are acceptable in Iranian society. This questionnaire can be applied for more precise evaluation of quality of life in patients with colorectal cancer in the future studies.