Following in the footsteps of earlier research demonstrating that their Preoperative Evaluation Clinic (PEC) decreased their 30-day readmission rate, researchers at New York University School of Medicine have now found that patients who attend the clinic have a significantly shorter observed-to-expected hospital length of stay (LOS) than those who do not attend.
These results, they said, help demonstrate that the value of PECs far exceeds the time and resources needed for their implementation.
“One of my first goals as medical director of the PEC was to establish some metrics to determine our value to the perioperative process,” said Jeanna D. Blitz, MD, assistant professor of anesthesiology, perioperative care and pain medicine at the New York City institution.
“Prior studies of anesthesiologist-directed PECs have demonstrated a decrease in total hospital length of stay. However, those reductions were mainly due to a reduction in admission prior to surgery with little or no decrease in the actual postoperative length of stay. And length of stay is an important metric for us, because it’s directly related to outcomes, hospital efficiency, patient satisfaction, overall cost of care and quality of care.”
To better understand this relationship, Dr. Blitz and her colleagues analyzed 28,828 elective inpatient surgical encounters (all procedures; all ages) at NYU Langone Medical Center between May 2011 and July 2013 that contained relevant data. Propensity scoring methods were used to compare the observed-to-expected LOS ratio between patients who attended (n=17,593) and did not attend (n=11,235) the PEC, after controlling for selection bias. A separate analysis was then performed to determine any differences in the variable direct cost of care between patients who had been seen in the PEC and those who had not.
Clinic Found Effective
“Patients seen in PEC were slightly older and had a higher incidence of hypertension and obesity than those who were not,” Dr. Blitz said, reporting the results at the 2015 annual meeting of the American Society of Anesthesiologists (abstract BOC04). “They were more frequently ASA [American Society of Anesthesiologists performance status] II and above, were less likely to be an emergency surgery and had higher surgical severity scores. And since we were not able to obtain a good match with respect to ASA status and emergency status, the final model adjusted for this.”
The observed-to-expected LOS ratio was 0.18 lower in patients who were seen in the PEC than their counterparts who were not (95% CI, 0.21 to –0.15; P<0.001). Similar results were obtained after propensity score weighting. This, Dr. Blitz noted, indicated an efficient preoperative process. The observed LOS was also shorter in patients who had been seen in the PEC.
For the study’s financial analysis, 28,643 surgical encounters were included. The mean variable direct cost per case was $5,754 for patients seen in the PEC and $7,127 for those who were not—a savings of $1,373 per case.
“So a visit to our PEC was associated with a significantly lower observed-to-expected length of stay ratio among patients presenting for elective inpatient surgery,” Dr. Blitz said. “And while studies have commonly recorded the effects of an intervention based on the observed length of stay, the observed-to-expected length of stay ratio is a more revealing metric.
“Presenting the observed length of stay in the context of the expected length of stay provides information about an intervention’s relative impact on hospital efficiency,” she continued. “And given that the length of stay is increased in patients who experience postoperative complications, the PEC clinic may also contribute by identifying patients at higher risk for complications early enough in the surgical process to intervene. This may ultimately result in better surgical candidate selection and fewer postoperative complications.”
Session co-moderator Brian Kavanagh, MB, questioned how the lack of a control group and randomization may have affected their results. “There’s no real argument that you’ve matched people as best you can,” said the professor and chair of the Department of Anesthesia at the University of Toronto. “But it’s a black box after that. Do you have any sense that the patients were discharged in comparable condition? This is important because the clinician discharging them likely knew whether the patient had attended the clinic.”
“All patients were subjected to the same standard of care at our institution,” Dr. Blitz responded. “It’s not clear to me that there was an indicator to the discharging clinician as to whether or not the patient had been seen in the PEC.”