Background: Clinical decision support (CDS) tools facilitate value based cancer care delivery and can enable measurement of guideline concordance, but can be challenging to implement. Flatiron Assist is an EHR-embedded and customizable CDS tool which facilitates selection and documentation of NCCN Guideline concordant and NCCN Preferred treatment regimens. We assessed performance metrics after the first year of use of this tool at eleven sites of care. Methods: We reviewed all non-small cell lung cancer (NSCLC) treatment orders as entered at 11 community practice sites of care in the northeast and southeast US from launch May 15, 2020, through May 23, 2021. Use of the CDS tool is not mandatory at these practices, and is deployed via prescriber choice. The tool documents and reports various quality metrics. We describe monthly prevalence of the CDS tool use, proportion of orders documented as guideline concordant, and prescriber-reported reasons for non-concordance. Results: All 954 NSCLC treatment regimen orders by the 89 prescribers who had the option to use the CDS tool were analyzed during the 1 year observation period. 658 regimens (69%) were ordered via the tool. Table describes prescriber users and non-users over time. The tool was deployed for 60% of NSCLC orders at 2 months, 69% at 6 months and 78% at 1 year post launch. Over the observed time period, 92% of treatment regimens ordered via the tool were documented as guideline concordant (94% at 2 months, 96% at 6 months and 85% at 1 year post-launch). Prescriber-reported reasons for ordering non-concordant regimens were “physician choice” (59%), “patient status” (12%), “newly published evidence” (10%), “second opinion from outside institution” (9%), “financial burden on patient/insurance doesn’t cover” (5%), “patient choice” (2%) and “other (allergy, disease progression, atypical disease)” (3%). Conclusions: At the study sites, this EHR-embedded CDS tool was rapidly adopted by most prescribers (approximately two thirds within 6 months of launch), and used for the majority of NSCLC candidate order sets during the 1 year observation period. NCCN concordance among users was empirically high overall and declined slightly over time, perhaps due to increased usage and/or greater comfort with the optional tool with ongoing use. Prescribers most commonly self-attributed the selection of non-concordant therapy to “physician choice” as opposed to factors such as financial hardship or patient choice. Further research will characterize workflow time, predictors of non-use and non-concordant orders, and evaluate whether Flatiron Assist improves clinical outcomes.

Total: 89 (37 physicians, 52 non-physicians) *”non-physician” includes NPs, PAs, PharmDs and RNs.