psychometric properties of the iranian version of colorectal cancer specific quality of life questionnaire (eortc qlq-cr29)

Background: the authors selected european organization for research and treatment (eortc) c30 and eortc qlq cr29 to specify bowel, bladder, and sexual dysfunction of iranian colorectal cancer patients. methods: a sample of 100 patients with colorectal cancer attending iran cancer institute from march 2012 to march 2013 at first-line chemotherapy in the adjuvant or palliative settings participated in the study. patients responded to the study questionnaires at the beginning and after 3-4 cycles of chemotherapies. responses to the core questionnaire (qlq-c30) and the qlq-cr29 were linearly converted into 0-100 scores, using the eortc guidelines. correlations between the qlq-c30 and qlq-cr29 were examined, using pearson’s product moment correlation in order to assess construct validity. known groups’ comparon examined the ability of eorct-cr29 to dtinguh between subgroups of patients with and without a stoma. sensitivity to changes over time was examined by the response to chemotherapy in palliative or neoadjuvant settings. internal constency was measured using cronbach’s alpha coefficient with estimates of a magnitude of 0.7. results: the mean age of patients was 53.6. based on clinical and pathologic staging, 60% of the patients had presented while their cancer was in stage iv with dtant metastas at the time of referring to the clinic. thirty-three percent of patients, almost all from rectal tumor group, had a permanent ostomy. in general, the correlation between the eortc qlq-c30 and qlq-cr29 was in the expected directions, demonstrating that functional scales of both questionnaires had a positive correlation with each other while negative correlation was observed between functional and symptom subscales. in addition, the qlq-cr29 differed considerably between patients with and without a stoma.the qlq-cr29 results showed improved functioning scores after treatment and at the same time symptoms decreased. the cronbach’s alpha for the scales ranged from 0.48-0.77. conclusion: in general, the iranian version of the eortc qlq-cr29 worked well and now could be used in outcome studies in colorectal cancer.