Development and validation of a NCC-BC-A scale to assess patient-reported outcomes for advanced breast cancer patients in China

e13125 Background: The primary therapeutic objectives for advanced breast cancer (ABC) are to extend patients’ survival time and to maintain their quality of life (QoL). Patient-reported outcomes (PROs) symptom could improve communication with physicians, and decreased utilization of unplanned healthcare. However, localized PROs scales for ABC were seldomly used in China. This study aimed to develop a specific PROs scale for ABC patients in China and optimize the management model for breast cancer. Methods: A literature search was conducted in PubMed, Embase, Wanfang, and CNKI databases, and the dimensions and items of the scale in the literature were extracted for the item pool. Delphi method was used to modify, add, subtract, and adjust the language of scale items until the experts' suggestions or opinions reached a consensus, and the first draft of the scale was formed. The first draft of the scale was further optimized by cognitive test and pre-survey. The optimized scale was used for formal survey, and the items of the scale were further analyzed and screened by coefficient of variation, correlation coefficient, internal item consistency, factor analysis, reliability, and validity. All tests were two-sided tests, and the test level was α=0.05. Results: A total of 10945 articles were analyzed, and 237 were finally included to form an item pool containing 277 PRO items. Two rounds of Delphi expert consultation were conducted, and the average authority coefficient of experts was Cr>0.7. Based on the results of cognitive test, the corresponding items were revised by language description to facilitate understanding. After adjustments according to the pre-survey of 200 ABC patients, the PROs scale NCC-BC-A was finally formulated with a total of 38 items, including 9 physiological dimension items, 4 psychological dimension items, 9 social dimension items, 11 treatment-evaluation items, 4 overall self-evaluation dimension items, and 1 other dimension. A total of 588 ABC patients participated in the national formal survey of NCC-BC-A with the average answer time of 6 minutes, and no floor or ceiling effects were observed. A series of statistical tests were conducted on the result. A principal component analysis revealed that the items in PROs scale have great consistency while preserving enough differences between different dimensions. The results were tested to be normally distributed with good variation. Also, the PROs scale survey result has an excellent Cronbach's α coefficient of 0.925 and an excellent test-retest reliability of 0.9041. Conclusions: The PROs scale NCC-BC-A has high validity and reliability, can objectively measure the QoL of ABC patients. NCC-BC-A fully considered the characteristics of treatment status for ABC patients, and the realistic situation in China, which may help clinicians to pay more attention to QoL of ABC patients and to optimize management system for ABC.