Real-life implementation of the SCOT trial findings: An interrupted time series analysis

e19341 Background: The Short Course Oncology Treatment (SCOT) trial demonstrated that three months of adjuvant, doublet chemotherapy for patients with colorectal cancer was non-inferior and significantly less toxic than six months. To understand if and how these results were implemented, this study analysed prescribing practice before and after dissemination of the SCOT results at a population level. Methods: Individual electronic records for patients in a Scottish health board (population 1.1 million) were reviewed (January 2010-June 2019) to explore the proportion of patients receiving over three months of treatment pre and post-SCOT. Logistic and linear regression were used in an interrupted time series analysis to estimate prescribing practices, and to assess the counterfactual situation in which the trial had not occurred. Patients receiving single agent chemotherapy were the comparator group. Predictors of patients receiving a longer duration of treatment post-SCOT were also identified. Results: In total, 998 patients received adjuvant chemotherapy; 564 doublet and 434 single agent. For those prescribed doublet chemotherapy, there was a significant decrease in the proportion receiving more than 3 months of treatment after the SCOT trial results (20%) versus pre-SCOT (84%, p < 0.001). Disease risk was a key predictor for longer duration of treatment post-SCOT. Table outlines the predicted practice post-SCOT (June 2019) for the modelled and counterfactual scenarios. Conclusions: A clear change in treatment duration for patients receiving doublet chemotherapy was observed. Disease stage influencing post-SCOT prescribing aligns with recently updated clinical guidelines. This methodology can be applied to explore the implementation of future trials and to highlight any barriers to implementation that exist. [Table: see text]