The EORTC QLQ-CR29 quality of life questionnaire for colorectal cancer: validation of the Dutch version

PURPOSE: To validate the Dutch version of the EORTC QLQ-CR29 quality of life questionnaire for colorectal cancer. METHODS: We translated and pilot-tested the original questionnaire in the Netherlands, following EORTC guidelines. We assessed factor structure, reliability and construct validity in different samples of patients from four hospitals. RESULTS: Of 296 patients, 236 (80 %) returned the questionnaire, and 27 out of 48 patients returned the retest questionnaire. In addition to the original three scales, we found a reliable bowel functioning scale (α = 0.80), reducing the number of individual items by five. Two of the other scales had sufficient to good reliability (urinary frequency, α = 0.71, original α = 0.75, body image α = 0.80, original α = 0.84), the third, blood and mucus in stool, only moderate (α = 0.56, original α = 0.69). Item functioning was sufficient to excellent for all but two items (urinary incontinence and dysuria). Construct validity was similar to that in earlier studies. CONCLUSION: We found a very satisfactory scale for bowel problems, in patients both with and without stoma. The body image and urinary incontinence scales were reliable, and construct validity was sufficient. We suggest the questionnaire to be adapted to decrease the number of individual items, improve the scales, and therefore increase reliability of the entire questionnaire.