Which Patient Factors Best Predict Discharge Destination After Primary Total Knee Arthroplasty? The ARISE Trial

A systematic literature review of predicting patient discharges using statistical methods and machine learning

Discharge planning is integral to patient flow as delays can lead to hospital-wide congestion. Because a structured discharge plan can reduce hospital length of stay while enhancing patient satisfaction, this topic has caught the interest of many healthcare professionals and researchers. Predicting discharge outcomes, such as destination and time, is crucial in discharge planning by helping healthcare providers anticipate patient needs and resource requirements. This article examines the literature on the prediction of various discharge outcomes. Our review discovered papers that explore the use of prediction models to forecast the time, volume, and destination of discharged patients. Of the 101 reviewed papers, 49.5% looked at the prediction with machine learning tools, and 50.5% focused on prediction with statistical methods. The fact that knowing discharge outcomes in advance affects operational, tactical, medical, and administrative aspects is a frequent theme in the papers studied. Furthermore, conducting system-wide optimization, predicting the time and destination of patients after discharge, and addressing the primary causes of discharge delay in the process are among the recommendations for further research in this field.

The Effect of Intravenous Tranexamic Acid on Perioperative Blood Loss, Transfusion Requirements, Verticalization, and Ambulation in Total Knee Arthroplasty: A Randomized Double-Blind Study

Background and Objectives: Total knee arthroplasty (TKA) is sometimes associated with significant perioperative bleeding. The aim of this study was to determine the efficacy of tranexamic acid (TXA) in reducing perioperative blood loss in patients undergoing primary TKA. The secondary objectives were to assess the efficacy of TXA in reducing the need for blood transfusion in these patients and to determine its effect on verticalization and ambulation after TKA. Materials and Methods: This study included 96 patients who were randomly assigned to two groups, each containing 48 patients. The study group received intravenous TXA at two time points: immediately after the induction with doses of 15 mg/kg and 10 mg/kg 15 min before the release of the pneumatic tourniquet. The control group received an equivalent volume of 0.9% saline solution via the same route. Results: TXA markedly reduced (Z = -6.512, p < 0.001) the total perioperative blood loss from 892.56 ± 324.46 mL, median 800 mL, interquartile range (IQR) 530 mL in the control group, to 411.96 ± 172.74 mL, median 375 mL, IQR 200 mL, in the TXA group. In the TXA group, only 5 (10.4%) patients received a transfusion, while in the control group, 22 (45.83%) received it (χ2 = 15.536, p = 0.001). Patients in the study group stood (χ2 = 21.162, p < 0.001) and ambulated earlier postoperatively, compared to the control group (χ2 = 26.274, p < 0.001). Patients who received TXA had a better overall postoperative functional recovery. There was a statistically significant difference in all the above results. Conclusions: TXA is an effective drug for reducing the incidence of perioperative bleeding, decreasing transfusion rates, and indirectly improving postoperative functional recovery in patients undergoing primary TKA.

Positive COVID-19 Diagnosis Following Primary Elective Total Joint Arthroplasty: Increased Complication and Mortality Rates

BACKGROUND

This study analyzed complication rates following primary elective total joint arthroplasty (TJA) in patients who subsequently contracted COVID-19.

METHODS

A large national database was queried for adult patients who underwent primary elective TJA in 2020. Patients who contracted COVID-19 after total knee arthroplasty (TKA) or total hip arthroplasty (THA) underwent 1:6 matching (age [±6 years], sex, month of surgery, COVID-19-related comorbidities) to patients who did not. Differences between groups were assessed using univariate and multivariate analyses. Overall, 712 COVID-19 patients were matched to 4,272 controls (average time to diagnosis: 128-117 days [range, 0-351]).

RESULTS

Of patients diagnosed <90 days postoperatively, 32.5%-33.6% required COVID-19-driven readmission. Discharge to a skilled nursing facility (adjusted odds ratio [aOR] 1.72, P = .003) or acute rehabilitation unit (aOR 4.93, P < .001) and Black race (aOR 2.28, P < .001) were associated with readmission after TKA. Similar results were associated with THA. COVID-19 patients were at increased risk of pulmonary embolism (aOR 4.09, P = .001) after TKA and also periprosthetic joint infection (aOR 4.65, P < .001) and sepsis (aOR 11.11, P < .001) after THA. The mortality rate was 3.51% in COVID-19 patients and 7.94% in readmitted COVID-19 patients compared to 0.09% in controls, representing a 38.7 OR and 91.8 OR of death, respectively. Similar results were observed for TKA and THA separately.

CONCLUSION

Patients who contracted COVID-19 following TJA were at greater risk of numerous complications, including death. These patients represent a high-risk cohort who may require more aggressive medical interventions. Given the potential limitations presently, prospectively collected data may be warranted to validate these findings.

Modifiable factors influencing length of stay after total knee arthroplasty

PURPOSE

This cohort study aims to investigate the current Rapid-Recovery-(RR)-pathway at an orthopaedic surgery hospital centre and to identify preoperative, intraoperative, and postoperative factors that are significantly associated with prolonged hospital Length of Stay (LOS) after total knee arthroplasty (TKA).

METHOD

A total of 194 patients undergoing primary TKA were included in this retrospective study. Sociodemographic data documented were age, gender, body mass index, living situation, and the clinical diagnosis. Factors affecting patient constitution and laboratory data for serum level of Hb and CRP were assessed preoperatively and postoperatively. In addition, we collected patients' data for attendance of patient education, planned discharge to rehabilitation facilities, and levels of postoperative pain.

RESULTS

In univariate group comparisons, prolonged LOS was significantly associated with increased age, elevated C-reactive-Protein-level, and decreased haemoglobin level. Patients experiencing prolonged LOS also showed significant association with higher prevalence of comorbidities, female gender, living as widow, preoperative anticoagulation, requirement of blood transfusion, and planned discharge to rehabilitation facilities. However, after multivariate logistic regression, only planned discharge to rehabilitation facility, non-attendance of preoperative patient education, female gender, and increased pain levels were identified as significant predictors for prolonged LOS.

CONCLUSION

Efficient pain therapy and thorough patient education have a positive effect on treatment outcome after TKA in a RR-setting.

Postsurgical Opioid Use Among Veterans Discharged to Skilled Care Facilities Compared to Veterans Discharged to Home After Orthopedic Surgery

OBJECTIVES

To compare opioid use patterns among Veterans who were discharged to a skilled care facility vs home after orthopedic surgery at a VA hospital.

DESIGN

We conducted a retrospective cohort study of Veterans who had orthopedic surgery at the Salt Lake City VA Medical Center (VAMC) between January 2018 and December 2021 and were followed by a transitional pain service. The principal outcome of interest was the time to stop opioid use after discharge from the hospital.

SETTING AND PARTICIPANTS

Veterans not already on chronic opioid therapy who had orthopedic surgery at the Salt Lake City VAMC and were followed by a transitional pain service.

METHODS

448 patients were included in the study, of which 371 (83%) were discharged to home and 77 (17%) were discharged to a skilled care facility. Median days to opioid cessation were estimated using the Kaplan-Meier method with 95% CIs and compared with discharge disposition using a log-rank test. Time to opioid cessation following hospital discharge was compared to baseline characteristics using univariable and multivariable Cox proportional hazards models.

RESULTS

Patients who were discharged to a skilled care facility used opioids for twice as long as those who were discharged home [median days (interquartile range)]: 22 (19, 26) vs 11 (10, 12), P < .001, respectively. When controlling for baseline characteristics in the multivariable analysis, discharge to a skilled care facility was significantly associated with continued opioid use at all time points [hazard ratio 0.63 (95% CI 0.44, 0.89), P = .009].

CONCLUSIONS AND IMPLICATIONS

Veterans discharged to a skilled care facility after orthopedic surgery used opioids for twice as long as those who were discharged to home. As postsurgical pain management guidelines change to focus on nonopioid pain modalities and opioid reduction, skilled care providers should adapt those strategies for their facilities.

Is there a difference in mobility and inpatient physical therapy need after primary total hip and knee arthroplasty? A decade-by-decade analysis from 60 to 99 years

INTRODUCTION

Extended inpatient rehabilitation (PT) after total hip (THA) and knee arthroplasty (TKA) has a significant impact on total care costs. As patients age, extended PT might be required following THA and TKA. This study examined the relationship between patient age, functional mobility, inpatient PT need, and discharge disposition in THA and TKA patients.

MATERIALS AND METHODS

This retrospective study included patients aged 60 + undergoing primary THA or TKA between 2018 and 2020 at an orthopedic hospital. Comparing by age-decade, 7374 (3600 THA, 3774 TKA) sexagenarians, 5350 (2367 THA, 2983 TKA) septuagenarians, 1356 (652 THA, 704 TKA) octogenarians, and 78 (52 THA, 26 TKA) nonagenarians were analyzed. We compared the number of PT sessions needed for discharge clearance and the postoperative functional mobility using the Activity Measure for Post-Acute Care (AM-PAC) tool. Statistical analyses included ANOVA with post-hoc Tukey's HSD for continuous data and Chi-squared test for categorical variables.

RESULTS

The number of PT sessions required for discharge clearance increased with age after THA (3.3 ± 1.9 sessions vs 3.8 ± 2.1 vs 5.0 ± 2.7 vs 6.2 ± 3.0; p < 0.01) and TKA (4.0 ± 2.1 vs 4.7 ± 3.1 vs 5.2 ± 2.8 vs 5.0 ± 1.6; p < 0.01). The functional mobility improvement as measured by AM-PAC was significantly lower for nonagenarians after THA (4.9 ± 2.8 vs 5.1 ± 2.8 vs 4.6 ± 3.3 vs 3.3 ± 3.9; p < 0.01) and TKA (5.0 ± 2.9 vs 4.7 ± 3.2 vs 3.9 ± 3.4 vs 3.2 ± 2.6; p < 0.01).

CONCLUSION

Patients in their eighth and ninth decade had less improvement in functional mobility during in-hospital rehabilitation and utilized more PT services. However, clinical results in the elderly are still satisfying and the data may be helpful for resource utilization planning and risk-adjustment in value-based payment models.

Patient factors associated with referral to inpatient rehabilitation following knee or hip arthroplasty in a public sector cohort: A prognostic factor study

RATIONALE, AIMS AND OBJECTIVES

Inpatient rehabilitation following total knee or hip arthroplasty (TKA, THA) is resource intensive and expensive. Understanding who is referred is integral to the discourse concerning service and cost reform. This study aimed to determine patient prognostic factors associated with referral to inpatient rehabilitation following TKA or THA in a public sector setting. In this setting, surgeon or patient choice does not drive referral.

METHOD

Prognostic factor research based on secondary analysis of prospectively collected data. Consecutive people undergo elective, primary TKA, or THA at a high-volume public hospital. The outcome was referral to inpatient rehabilitation after acute care. Patient variables including sociodemographic, comorbidity, and complication details were used in multivariable logistic regression to determine the prognostic factors associated with referral.

RESULTS

Five hundred twenty people were included; 9.2% experienced the outcome. In the multivariable model, acute complications (OR 3.6, 95% CI 1.6-7.8), TKA surgery (OR 3.1, 95% CI 1.0-9.4), renal disease (OR 4.4, 95% CI 1.4-13.3), and higher body mass index (OR 1.1, 95% CI 1.0-1.2) were associated with referral; unilateral surgery (OR 0.1 (95% CI 0.01-0.2) and previous arthroplasty (OR 0.3 (95% CI 0.1-0.8) were protective. There were no significant associations found for sociodemographic factors (such as gender and residential status) in the multivariable model.

CONCLUSION

In the absence of choice, physical impairment and health factors are associated with referral to inpatient rehabilitation following TKA or THA.

Development of a Machine Learning Algorithm to Predict Nonroutine Discharge Following Unicompartmental Knee Arthroplasty

BACKGROUND

Reliable and effective prediction of discharge destination following unicompartmental knee arthroplasty (UKA) can optimize patient outcomes and system expenditure. The purpose of this study is to develop a machine learning algorithm that can predict nonhome discharge in patients undergoing UKA.

METHODS

A retrospective review of a prospectively collected national surgical outcomes database was performed to identify adult patients who underwent UKA from 2015 to 2019. Nonroutine discharge was defined as discharge to a location other than home. Five machine learning algorithms were developed to predict this outcome. Performance of the algorithms was assessed through discrimination, calibration, and decision curve analysis.

RESULTS

Overall, of the 7275 patients included, 263 (3.6) patients were unable to return home upon discharge following UKA. The factors determined most important for identification of candidates for nonroutine discharge were total hospital length of stay, preoperative hematocrit, body mass index, preoperative sodium, American Society of Anesthesiologists classification, gender, and functional status. The extreme boosted model achieved the best performance based on discrimination (area under the curve = 0.875), calibration, and decision curve analysis. This model was integrated into a web-based open access application able to provide both predictions and explanations.

CONCLUSION

The present model can, following appropriate external validation, be used to augment clinician decision-making in patients undergoing elective UKA. Patients with high preoperative probabilities of nonroutine discharge based on nonmodifiable risk factors should be counseled to start the insurance authorization process with case management to avoid unnecessary inpatient stay, and those with modifiable risk can attempt prehabilitation to optimize these parameters before surgery.

Preoperative Cognitive Impairment as a Perioperative Risk Factor in Patients Undergoing Total Knee Arthroplasty

Background:

The study assessed whether pre-existing cognitive impairment (CI) prior to elective total knee arthroplasty (TKA) is associated with worse postoperative outcomes such as delirium, in-hospital medical complications, 30-day mortality, hospital length of stay and non-home discharge.

Methods:

A retrospective database analysis from the NSQIP Geriatric Surgery Pilot Project was used. There was an initial cohort of 6350 patients undergoing elective TKA, 104 patients with CI were propensity score matched to 104 patients without CI.

Results:

Analysis demonstrated a significantly increased incidence of post-operative delirium (POD) in the cohort with pre-op CI (p = < .001), a worsened functional status (p = < .001) and increased nonhome discharge postoperatively compared to the group without CI (p = 0.029). Other post-operative outcomes included 30-day mortality of 0% in both groups, and low rate of complications such as infection (2.88% vs 0.96%), pneumonia (1.92% vs 0%), failure to wean (0.96% vs 0%), and reintubation (0.96% vs 0%). Some other differences between the CI group and non-CI group, although not statistically significant, included increased rate of transfusion (10.58% vs 6.73%), and sepsis (1.92% vs 0%). The length of stay was increased in the non-CI group (4.28% vs 2.32%, p = 0.122).

Conclusion:

CI in patients undergoing TKA is associated with an increased risk of POD, worsened postoperative functional status, and discharge to non-home facility.

Differences in Immediate Postoperative Outcomes Between Robotic-Assisted TKA and Conventional TKA

Background

Robotic-assisted total knee arthroplasty (TKA) is a growing technique in adult reconstruction. The variations between robotic-assisted and conventional TKA could lead to changes in immediate postoperative outcomes. We aimed to evaluate for differences in postoperative pain, discharge day, as well as post-hospital disposition (home vs subacute rehabilitation facility [SAR]) between robotic-assisted and conventional TKA.

Methods

We retrospectively identified 2 cohorts of patients who underwent either conventional or robotic-assisted TKA between January 2019 and July 2019. Their average pain scores from postoperative day 0, day 1, and day 2 were recorded. Their postoperative discharge day was recorded, as well as their disposition to either home or a SAR. Preoperatively, all patients are offered robotic-assisted TKA, and only those who want the procedure and undergo a preoperative CT scan receive the robotic-assisted surgery. Statistical analysis was conducted using SPSS.

Results

One hundred sixty-six patients were identified with 83 in each cohort. No differences between age, race, and gender were found. Despite minor variations in pain levels, the overall postoperative pain score analysis did not strongly favor one technique over the other. The robotic-assisted group had a significantly higher amount of patients discharged to home instead of a SAR and also had a shorter time to discharge than the conventional group.

Conclusions

Robotic-assisted TKA has similar postoperative pain scores compared with conventional TKA. The robotic-assisted cohort demonstrated other benefits including earlier discharge and are more likely to be discharged home instead of a SAR.