Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Reliability of 95% confidence interval revealed by expected quality-of-life scores: an example of nasopharyngeal carcinoma patients after radiotherapy using EORTC QLQ-C 30 | Chien et al. Health and Quality of Life Outcomes 2010 8 68 http content 8 1 68 I HEALTH AND QUALITY OF LIFE OUTCOMES RESEARCH Open Access Reliability of 95 confidence interval revealed by expected quality-of-life scores an example of nasopharyngeal carcinoma patients after radiotherapy using EORTC QLQ-C 30 Tsair-Wei Chien1 2 Shun-Jin Lin23 Wen-Chung Wang4 Henry WC Leung5 Wen-Pin Lai6 and Agnes LF Chan 41 3 Abstract Background Many researchers use observed questionnaire scores to evaluate score reliability and to make conclusions and inferences regarding quality-of-life outcomes. The amount of false alarms from medical diagnoses that would be avoided if observed scores were substituted with expected scores is interesting and understanding these differences is important for the care of cancer patients. Using expected scores to estimate the reliability of 95 confidence intervals CIs is rarely reported in published papers. We investigated the reliability of patient responses to a quality-of-life questionnaire and made recommendations for future studies of the quality of life of patients. Methods A total of 115 patients completed the EORTC core questionnaire QLQ-C30 version 3 after radiotherapy. The observed response scores assumed to be one-dimensional were summed and transformed into expected scores using the Rasch rating scale model with WINSTEPS software. A series of simulations was performed using a unified bootstrap procedure after manipulating scenarios with different questionnaire lengths and patient numbers to estimate the reliability at 95 confidence intervals. Skewness analyses of the 95 CIs were compared to detect different effects between groups according to the two data sets of observed and expected response scores. Results We found that 1 it is necessary to report CIs for reliability and skewness coefficients in papers 2 data derived from expected response scores are preferable to making inferences and 3 visual representations displaying the
