Employing An Oncology Decision-Support System To Quantify Treatment Variation.

e18067 Background: Factors affecting cancer treatment may include evidence for effectiveness, cost, and preference. These influences can lead to treatment variation across institutions and populations. Decision-support systems have been proposed as tools to reduce variation. This study quantified concordance between treatment provided by oncologists in China and therapeutic options presented by a decision-support tool. Methods: We identified and analyzed concordance studies in nine unique institutions located in seven provinces in China, published in 2017-2018 using Watson for Oncology (WFO), a clinical decision-support tool. Published rates of concordance were compared by cancer type and institution. Results: Concordance of all combined cases was 59% (2012/3388). Concordance rates varied by cancer type and institution (Table). Concordance rates were highest for ovarian (96%), rectal (94%) and breast (89%) cancers but lowest in gastric (12%), ovarian (43%) and breast (55%) cancers. Conclusions: Concordance between treatments and therapeutic options from an oncology decision-support tool varied significantly across cancer types and institutions in China, suggesting significant practice variation. Without established guidelines for treatment, clinical decisions may be influenced by preferences and local factors. Future studies are needed to identify reasons for variation and improve adherence to regional evidence-based guidelines. [Table: see text]