RESUMEN
AIM: Optimal oncological resection in cancers of the lower rectum often requires a permanent colostomy. However, in some patients a colostomy may have a negative impact on health-related quality of life (HRQoL). The Colostomy Impact (CI) score is a simple questionnaire that identifies patients with stoma dysfunction that impairs HRQoL by dividing patients into 'minor' and 'major' CI groups. This aim of this study is to evaluate construct and discriminative validity, sensitivity, specificity and reliability of the CI score internationally, making it applicable for screening and identification of patients with stoma-related impaired HRQoL. METHOD: The CI score was translated in agreement with WHO recommendations. Cross-sectional cohorts of rectal cancer survivors with a colostomy in Australia, China, Denmark, the Netherlands, Portugal, Spain and Sweden were asked to complete the CI score, the European Organization for Research and Treatment of Cancer (EORTC) quality of life 30-item core questionnaire, the stoma-specific items of the EORTC quality of life 29-item colorectal-specific questionnaire and five anchor questions assessing the impact of colostomy on HRQoL. RESULTS: A total of 2470 patients participated (response rate 51%-93%). CI scores were significantly higher in patients reporting reduced HRQoL due to their colostomy than in patients reporting no reduction. Differences in EORTC scale scores between patients with minor and major CI were significant and clinically relevant. Sensitivity was high regarding dissatisfaction with a colostomy. Regarding evaluation of discriminative validity, the CI score relevantly identified groups with differences in HRQoL. The CI score proved reliable, with equal CI scores between test and retest and an intraclass correlation coefficient in the moderate to excellent range. CONCLUSION: The CI score is internationally valid and reliable. We encourage its use in clinical practice to identify patients with stoma dysfunction who require further attention.