Reference guidelines improve residents' ability to order appropriate preoperative tests in standardized case scenarios

Background: Preoperative testing for surgery is estimated to cost $30 billion annually. The goal of this study was to determine the relative influence of access to a guideline reference for preoperative test ordering appropriateness by resident physicians in simulated case scenarios. Methods: At a single teaching hospital, 80 PGY (Post Medical School Graduation Year) 2-5 residents from anesthesiology, surgery, internal medicine, and obstetrics/gynecology were recruited to review simulated case scenarios. Participants within each specialty were randomized with half receiving supplemental ASA preoperative testing guidelines during completion of the questionnaire. Participants indicated which preoperative tests they believed appropriate for each scenario. Correct responses were set by an expert panel and results were reported as relative probabilities and 95% CI. Results: 66 surveys were analyzed. In the entire cohort, the group receiving supplemental guidelines achieved a greater percentage of correct answers (x=84.2%) compared to the group without guidelines (x=78.6%) (relprob =1.07 [CI 1.01-1.12], p=0.011). Correct answers improved to 1.07 [1.01-1.12] with a guideline across specialties and experience levels. Without a guideline, correct answer rates were greater for anesthesia vs surgery residents (1.19 [1.08, 1.31]) and anesthesia vs internal medicine residents (1.16 [1.04, 1.31]). With guidelines, these differences were maintained. Without a guideline, significant differences were noted between PGY 3 vs PGY 2 residents (1.12 [1.03, 1.23]) and PGY 4 vs PGY 2 residents (1.11 [1.03, 1.20]), but these differences were not present with guidelines. Surgery residents did not improve with the guideline. Conclusions: In a set of simulated clinical scenarios, reference to ASA-adapted guidelines improved test ordering by the majority of resident physicians. While anesthesia residents performed better than others independent of the guideline, the guideline negated the effect of experience in non-anesthesia trainees. Given the financial burden of inappropriate preoperative test ordering, further validation of the benefits of guideline implementation is warranted.