Retrospective Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Dec 18, 2018; 9(12): 285-291
Published online Dec 18, 2018. doi: 10.5312/wjo.v9.i12.285
Socio-demographic factors impact time to discharge following total knee arthroplasty
Ugonna N Ihekweazu, Garrett H Sohn, Mitzi S Laughlin, Robin N Goytia, Vasilios Mathews, Gregory W Stocks, Anay R Patel, Mark R Brinker
Ugonna N Ihekweazu, Robin N Goytia, Vasilios Mathews, Gregory W Stocks, Anay R Patel, Mark R Brinker, Fondren Orthopedic Group, Houston, TX 77030, United States
Ugonna N Ihekweazu, Mitzi S Laughlin, Robin N Goytia, Vasilios Mathews, Gregory W Stocks, Anay R Patel, Mark R Brinker, Fondren Orthopedic Research Institute, Fondren Orthopedic Group, Houston, TX 77030, United States
Garrett H Sohn, Department of Orthopedic Surgery, Baylor College of Medicine, Houston, TX 77030, United States
Author contributions: Ihekweazu UN, Goytia RN, Mathews V, Stocks GW, Patel AR and Brinker MR contributed to the study conception and design; Ihekweazu UN, Goytia RN, Mathews V, Stocks GW and Patel AR contributed to the data acquisition and data interpretation; Laughlin MS contributed the data analysis, data interpretation and preparation of the tables and figures; Ihekweazu UN, Sohn GH and Laughlin MS contributed to the literature review and the writing of the article; all authors have approved this manuscript prior to submission and believe that this manuscript represents honest work.
Institutional review board statement: This study was evaluated and an IRB exemption was given for this work by the Texas Orthopedic Hospital’s IRB (TOH203e).
Informed consent statement: Patients were not required to give informed consent to the study because the analysis used anonymous clinical data and the study was given an IRB exemption.
Conflict-of-interest statement: All authors declare no conflicts-of-interest related to this article but the following authors have financial relationships to report in general: Robin Goytia reports personal fees from Innomed, outside the submitted work; Gregory Stocks reports stock ownership from Nimbic Systems, Inc., outside the submitted work; Mark Brinker reports personal fees from Zimmer Biomet, outside the submitted work.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author to: Mitzi S Laughlin, PhD, Senior Researcher, Chief Scientist, Fondren Orthopedic Research Institute, Fondren Orthopedic Group, 7401 S. Main, Houston, TX 77030, United States.
Telephone: +1-713-7943408
Received: October 4, 2018
Peer-review started: October 4, 2018
First decision: October 29, 2018
Revised: November 6, 2018
Accepted: December 10, 2018
Article in press: December 10, 2018
Published online: December 18, 2018
Research background

Time to discharge or in-hospital length of stay (LOS) has been shown to directly influence the total cost of joint arthroplasty when patients are discharged home. Since LOS is a modifiable cost factor, increased focus has been placed on implementing measures that aim to discharge patients from the hospital as soon as safely possible. The recent development of short stay pathways is a direct result of advancements in surgical, anesthetic and rehabilitation techniques. Traditional factors such as age, gender, comorbidities and perioperative complications have been studied extensively and influence LOS. Patient social, logistical and demographic factors are non-modifiable factors but potentially influence LOS.

Research motivation

The motivation behind this research was to further improve short stay pathways by evaluating non-traditional factors that potentially could influence LOS. Our hypothesis was that social, logistical and demographic factors influence LOS following total knee arthroplasty (TKA) in a short stay pathway.

Research objectives

The primary purpose of this study was to assess the influence of social, logistical and demographic factors on time to discharge in a short stay pathway following TKA. The findings from this study may further enhance preoperative and perioperative risk stratification models that already incorporate patient characteristics and perioperative surgical factors but neglect other potentially influential variables.

Research methods

A retrospective chart review was performed for a consecutive series of 806 elective primary TKA’s performed at a single specialty hospital from January 2016 to December 2016. Potential variables associated with increased hospital LOS were obtained from patient medical records. These included age, gender, race, zip code, body mass index (BMI), number of pre-operative medications used, number of narcotic medications used, number of patient reported allergies (PRA), simultaneous bilateral surgery, tobacco use, marital status, living arrangements, distance traveled for surgery, employment history, surgical day of the week, procedure end time and whether the surgery was performed during a major holiday week. Thanksgiving, Christmas and New Year’s Eve were the major holidays included in the study. Baseline demographics, surgical factors, and social factors were summarized by mean (± SD) for continuous factors or by count and percentages for categorical factors in order to characterize the study population. Multivariate regression analysis was performed to determine the contribution of demographic, logistical and social factors on LOS.

Research results

Patients were discharged at a median of 49 h (post-operative day two). Six factors increased LOS: Simultaneous bilateral TKA, female gender, age, patient-reported allergies, later procedure end-times, and Black or African American patients. Decreased LOS was found in married patients and TKA’s performed during holiday weeks. Non-significant factors included: BMI, median income, patient’s living arrangement, smoking status, number of medications taken, use of pre-operative pain medications, distance traveled to hospital, and the day of surgery.

Research conclusions

The cost of TKA is dependent upon LOS, which is affected by multiple factors. The clinical care team should acknowledge socio-demographic factors to further optimize short stay pathways and decrease LOS.

Research perspectives

In an effort to decrease post-operative LOS, many institutions continue to develop optimal discharge pathways following TKA. Since LOS is dependent upon many variables, we sought to define which social, logistical and demographic factors influence LOS in TKA. Six factors were found to increase LOS in a short stay pathway: Age, gender, Black or African American race, simultaneous bilateral TKA, later procedure end times and number of PRA’s. Two factors decreased LOS: Patient being married and surgery during a major public holiday week. While none of the patient specific factors (e.g., age, race, gender, marital status, socioeconomic status, and PRA’s) are modifiable by the clinician, we do have the ability to optimize surgical schedule and allocation of resources. When refining predictive models for LOS, in addition to considering known clinical factors, the care team should also appreciate the extent that social, demographic and logistical factors influence LOS.