The impact of reduction of testing at a Preoperative Evaluation Clinic for elective cases: Value added without adverse outcomes

Abstract

Study objective: Protocol changes at Vanderbilt have been adopted with the intention of reducing unnecessary preoperative testing. We sought to evaluate their success and association with clinical decisions.

Design: Retrospective Observational Study SETTING: Vanderbilt's Preoperative Evaluation Clinic MEASUREMENTS: We reviewed and identified a key interval of change on clinical workup protocols which led to a reduction in preoperative testing. We queried Data Warehouse for preoperative chemistry tests, complete blood counts, coagulation blood draws, electrocardiograms, and chest x-rays done before and after these intervals. Chi-square, univariate and mixed effect multivariable regressions were performed to determine the significance of testing reduction and tendency of readmission rates and length-of-stay; Welch's t-test with Freeman-Tukey transformation was conducted to identify the differences in case cancellation rates.

Main results: We analyzed 56,425 anesthetic cases and there was a statistically significant downward trend in all preoperative testing performed: electrocardiograms (61.90% to 31.66% [OR 0.151; 95% CI 0.144 to 0.159]), coagulation blood draws (37.57% to 29.74% [OR 0.392; 95% CI 0.370 to 0.416]), basic metabolic panels (70.64% to 51.29% [OR 0.294; 95% CI 0.280 to 0.309]), blood cell counts (71.38% to 51.42% [OR 0.264; 95% CI 0.251 to 0.277]) and chest x-rays (11.80% to 6.04% [OR 0.417; 95% CI 0.384 to 0.452], to 3.13% [OR 0.473; 95% CI 0.431 to 0.519]) after protocol changed. The changes didn't induce a significant increase in case cancellations, length-of-stay, readmission or most DOS testing; except for BMPs (0.28% to 0.66% [OR 1.307; 95% CI 1.104 to 1.549]).

Conclusions: A net reduction in preoperative testing was seen at our institution from 2012 to 2015 due to anesthesia protocol changes intended to limit routine ordering of labs and imaging. While there was a significant increase in DOS testing for BMPs, these increases were not enough to offset the decrease in testing observed preoperatively.

Keywords: Anesthesiology; Preoperative care; Quality improvement.