BACKGROUND: To implement and prospectively validate a previously published decision-aid tool to guide ordering of preoperative type and screen tests (preT&S). STUDY DESIGN: In this interrupted time-series quasi-experimental study, we implemented a decision-aid tool for patients undergoing elective thoracic surgery at a single academic institution. Data was collected 6 months before and prospectively after implementation. The tool, a previously published nomogram, predicts the need for a preT&S using age, body mass index (BMI), planned operation, approach, and preoperative hemoglobin. We excluded patients who had prior transfusions, neoadjuvant therapy, redo operations and/or inpatient consults. We validated the tool using multivariable logistic regression, regression discontinuity, c-index, sensitivity, predictive values, and cost savings. RESULTS: 177 consecutive patients met inclusion criteria. 88 were after implementation, and 89 patients before. There were no differences between the groups in terms of age, sex, BMI, comorbidities, approach, nor preoperative hemoglobin (all p>
0.05). Overall transfusion rates were similar (6.8% vs 6.7%
p>
0.99)
however, the rate of ordering preT&S was reduced significantly (94.4% vs 60.2%
p<
0.001). At our institution, the decision aid tool resulted in cost savings of 5,048 over 6 months alone. With a c-index of 0.977, our validation demonstrated 100% sensitivity, 90.3% specificity, and 100% negative predictive value. CONCLUSIONS: Implementation and validation of the preT&S nomogram proved feasible, accurate, and resulted in reducing unnecessary testing and costs before elective non-cardiac thoracic surgery. Wider implementation has the potential for substantial cost savings.