# Does Surgical Day of Week Affect Patient Outcomes and Hospital Costs Following Lumbar Fusion?

## TL;DR

Surgery later in the week is linked to higher costs and worse patient outcomes after lumbar fusion, according to a study of over 700 patients.

## Contribution

This study is among the first to investigate how the day of the week affects outcomes and costs in lumbar fusion surgery.

## Key findings

- Late-week surgeries had higher costs, averaging $3,697 more than early-week surgeries.
- Late-week surgeries were more likely to result in non-home discharge and 30-day readmission.
- No differences in patient demographics or surgical complexity were found between early- and late-week surgeries.

## Abstract

Background

As the population ages, surgical intervention for degenerative spine conditions is increasing, and this causes a commiserate increase in healthcare expenditures associated with these procedures. Little research has been done on the effect of early-week versus later-week surgeries on patient outcomes, cost, and length of stay (LOS) in patients undergoing lumbar fusion surgery. The purpose of this study is to compare LOS, patient outcomes, and hospital costs between patients having surgery early in the week and later in the week.

Methods

A retrospective review of 771 patients undergoing a one-, two-, or three-level lumbar fusion from December 2020 to December 2023 at a single institution was performed. Demographics, surgical details, postoperative outcomes and cost were compared between patients who had surgery on Monday, Tuesday, and Wednesday, to those having surgery Thursday or Friday. Univariate and multivariate analyses were performed to compare the groups.

Results

There were no differences in age, sex, BMI, race, American Society of Anesthesiology (ASA) scores, Charlson Comorbidity Index (CCI) scores, number of operative levels or inpatient/outpatient status between early- and late-week surgeries. Postoperatively the only significant difference was cost, late-week surgeries were, on average, $3,697 more expensive than early-week surgeries ($26,506 vs. $22,809; p<0.001). On multivariate analysis late-week surgeries were 2.47 times more likely to have a non-home discharge (OR: 2.47, 95% CI: 1.24 to 4.95; p=0.010) and 2.19 times more likely to have a 30-day readmission (OR: 2.19, 95% CI:1.01 to 4.74; p=0.044) Additionally, late-week surgeries were $2,041.55 (β:2,041.55, 95% CI: 804.72 to 3,278.38; p=0.001) more expensive than early-week surgeries.

Conclusions

At our institution, patients undergoing one- to three-level lumbar fusion surgery on Thursday or Friday had a higher risk of non-home discharge, 30-day readmission, and incurred higher cost than those having early-week surgery. Further research is needed to elucidate the reasons for these findings and to evaluate interventions aimed at improving outcomes for patients undergoing surgery later in the week.