Patient Selection in Short Stay Total Hip Arthroplasty for Medicare Patients

Machine learning approaches in predicting ambulatory same day discharge patients after total hip arthroplasty

BACKGROUND

With continuing financial and regulatory pressures, practice of ambulatory total hip arthroplasty is increasing. However, studies focusing on selection of optimal candidates are burdened by limitations related to traditional statistical approaches. Hereby we aimed to apply machine learning algorithm to identify characteristics associated with optimal candidates.

METHODS

This retrospective cohort study included elective total hip arthroplasty (n=63 859) recorded in National Surgical Quality Improvement Program dataset from 2017 to 2018. The main outcome was length of stay. A total of 40 candidate variables were considered. We applied machine learning algorithms (multivariable logistic regression, artificial neural networks, and random forest models) to predict length of stay=0 day. Models' accuracies and area under the curve were calculated.

RESULTS

Applying machine learning models to compare length of stay=0 day to length of stay=1-3 days cases, we found area under the curve of 0.715, 0.762, and 0.804, accuracy of 0.65, 0.73, and 0.81 for logistic regression, artificial neural networks, and random forest model, respectively. Regarding the most important predictive features, anesthesia type, body mass index, age, ethnicity, white blood cell count, sodium level, and alkaline phosphatase were highlighted in machine learning models.

CONCLUSIONS

Machine learning algorithm exhibited acceptable model quality and accuracy. Machine learning algorithms highlighted the as yet unrecognized impact of laboratory testing on future patient ambulatory pathway assignment.

Converting hip and knee arthroplasty cases to same-day surgery due to COVID-19

AIMS

In 2020, the COVID-19 pandemic meant that proceeding with elective surgery was restricted to minimize exposure on wards. In order to maintain throughput of elective cases, our hospital (St Michaels Hospital, Toronto, Canada) was forced to convert as many cases as possible to same-day procedures rather than overnight admission. In this retrospective analysis, we review the cases performed as same-day arthroplasty surgeries compared to the same period in the previous 12 months.

METHODS

We conducted a retrospective analysis of patients undergoing total hip and knee arthroplasties over a three-month period between October and December in 2019, and again in 2020, in the middle of the COVID-19 pandemic. Patient demographics, number of outpatient primary arthroplasty cases, length of stay for admissions, 30-day readmission, and complications were collated.

RESULTS

In total, 428 patient charts were reviewed for October to December of 2019 (n = 195) and 2020 (n = 233). Of those, total hip arthroplasties (THAs) comprised 60% and 58.8% for 2019 and 2020, respectively. Demographic data was comparable with no statistical difference for age, sex, contralateral joint arthroplasty, or BMI. American Society of Anesthesiologists grade I was more highly prevalent in the 2020 cohort (5.1-times increase; n = 13 vs n = 1). Degenerative disc disease and fibromyalgia were less significantly prevalent in the 2020 cohort. There was a significant increase in same day discharges for non-direct anterior approach THAs (two-times increase) and total knee arthroplasty (ten-times increase), with a reciprocal decrease in next day discharges. There were significantly fewer reported superficial wound infections in 2020 (5.6% vs 1.7%) and no significant differences in readmissions or emergency department visits (3.1% vs 3.0%).

CONCLUSION

The COVID-19 pandemic meant that hospitals and patients were hopeful to minimize the exposure to the wards, and minimize strain on the already taxed inpatient beds. With few positives during the COVID-19 crisis, the pandemic was the catalyst to speed up the outpatient arthroplasty programme that has resulted in our institution being more efficient, and with no increase in readmissions or early complications. Cite this article: Bone Jt Open 2021;2(7):545-551.

Contemporary Outpatient Arthroplasty Is Safe Compared with Inpatient Surgery: A Propensity Score-Matched Analysis of 574,375 Procedures

BACKGROUND

Outpatient joint arthroplasty is a potential modality for increased case throughput and is rising in demand. However, we are aware of no study that has compared outcomes between risk-matched outpatient and inpatient procedures within the last 7 years. The aims of this study were to compare matched patient cohorts who underwent outpatient or inpatient joint arthroplasty in terms of 30-day adverse events and readmission rates.

METHODS

From the National Surgical Quality Improvement Program database, we identified patients who underwent primary total hip arthroplasty (THA), primary total knee arthroplasty (TKA), and primary unicompartmental knee arthroplasty (UKA) from 2009 to 2018. Using 10 perioperative variables, patients who underwent an outpatient procedure were 1:4 propensity score-matched with patients who underwent an inpatient procedure. The rates of 30-day adverse events and readmission were compared using the McNemar test. The risk factors for adverse events and readmissions were identified using multivariate regression.

RESULTS

Of 574,375 patients identified, 21,506 (3.74%) underwent an outpatient procedure. After propensity score matching, an outpatient joint arthroplasty was associated with a lower rate of adverse events (3.18% compared with 7.45%; p < 0.001). When assessed individually, outpatient TKA (3.15% compared with 8.11%; p < 0.001), THA (4.94% compared with 10.05%; p < 0.001), and UKA (1.78% compared with 3.39%; p < 0.001) were all associated with fewer adverse events overall and there was no difference in the rate of 30-day readmission, when compared with inpatient analogs. Outpatient joint arthroplasty was an independent factor for lower adverse events (odds ratio [OR], 0.407 [95% confidence interval (CI), 0.369 to 0.449]; p < 0.001), with no increase in the risk of readmission (OR, 1.004 [95% CI, 0.878 to 1.148]; p = 0.951).

CONCLUSIONS

Contemporary outpatient joint arthroplasty demonstrated lower rates of adverse events with no increased rate of 30-day readmission when compared with risk-matched inpatient counterparts. Although multiple factors should guide the decision for the site of care, outpatient arthroplasty may be a safe alternative to inpatient arthroplasty.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Assessment of Psychological Factors in Short-Stay Total Hip Arthroplasty Protocol

BACKGROUND

Several variables are known to correlate with the successful completion of short-stay total hip arthroplasty (THA) protocols. The role of psychological factors remains unclear. We investigated the interaction between patient-reported measures of psychological fitness and successful completion of a short-stay THA protocol.

METHODS

We performed a prospective cohort study of patients undergoing elective anterior total hip arthroplasty enrolled in a short-stay protocol (success defined as LOS ≤1 midnight versus failed, LOS >1 midnight). Psychological fitness was measured using the Patient-Reported Outcomes Measurement Information System (PROMIS) domains for self-efficacy, depression, anxiety, emotional support, and the ability to participate in social roles. PROMIS scores, patient demographics, and surgical factors were assessed for a relationship with failure to complete short-stay protocol.

RESULTS

Patients that failed to complete the short-stay protocol had higher mean pre-operative PROMIS depression scores (50.8 vs 47.1, P = .025) and anxiety scores (53.6 vs 49.2, P = .008) and higher postoperative PROMIS depression (48.19 vs 43.49, P = .003) and anxiety scores (51.7 vs 47.1, P = .01). Demographic and surgical variables did not correlate with the successful completion of the short-stay protocol. That seventy-six percent of the patients did not adhere to the short-stay protocol was due to the inability to complete a physical therapy standardized safety assessment.

CONCLUSION

Higher levels of preoperative and postoperative anxiety and depression in otherwise psychologically healthy patients, is associated with an increased risk of failure to complete a short-stay protocol following THA. Targeted interventions are needed to facilitate rapid recovery in patients with psychological barriers to early mobilization.

Patient Characteristics and Surgical Start Time Affect Length of Stay Following Anterior Total Hip Arthroplasty

BACKGROUND

Currently, no consensus exists for selection criteria of appropriate candidates for outpatient total hip arthroplasty (THA). This study evaluates patient characteristics associated with same-day discharge, examined surgical start time's effect on rates of same-day discharge, and compares readmission and reoperation rates between groups.

METHODS

All patients who underwent a THA by one surgeon at a single quaternary care hospital between February 2016 and May 2018 were captured. All patients were given the option for same-day discharge. Patient characteristics and perioperative variables were analyzed.

RESULTS

A total of 429 patients met inclusion criteria, 153 (36%) were discharged on the day of surgery. In a multivariate analysis, age (P = .000), multiple comorbidities (P = .004), and start time remained statistically significant (P = .000). Patients with start times prior to 9 AM had odds ratio of 11.56 of being discharged same day when compared to those with start times after 12 PM. Patients discharged the day of surgery were less likely to have a 90-day emergency room visit (P = .010), a readmission within 30 days (P = .001) or 90 days (P = .000), or a reoperation (0 vs 14, P = .003).

CONCLUSION

Same-day discharge following THA is safe and feasible. Patient's age and number of comorbidities should be considered when developing selection criteria for same-day discharge programs. Patients selected for same-day discharge should receive earlier operating room start times.

No Difference in Outcomes Between Short and Longer-Stay Total Joint Arthroplasty with a Discharge Home: A Propensity Score-Matched Analysis Involving 46,660 Patients

BACKGROUND

Outcomes following total hip arthroplasty (THA) and total knee arthroplasty (TKA) with a short length of hospital stay have been reported; however, most studies have not accounted for an inherent patient selection bias and discharge disposition. The purpose of this study was to utilize a propensity score to match and compare the outcomes of patients undergoing THA or TKA with short and longer lengths of stay with a discharge directly home.

METHODS

An administrative database from Ontario, Canada, which has a single-payer health-care system, was retrospectively reviewed to identify patients who underwent THA or TKA from 2008 to 2016. Patients were subsequently stratified into 2 groups based on their length of stay: short length of stay (≤2 days; thereafter referred to as short stay) and longer length of stay (>2 days; thereafter referred to as longer stay). Using a propensity score, patients who underwent short-stay THA or TKA were matched to patients who underwent longer-stay THA or TKA. Matching was based on 15 demographic, medical, and surgical factors. Our primary outcomes included postoperative complications, health-care utilization (readmission and emergency department presentation), and health-care costs.

RESULTS

Overall, 89,656 TKAs (14,645 short stays and 75,011 longer stays) and 52,610 THAs (9,426 short stays and 43,184 longer stays) were included in this study. Patients who underwent short-stay THA or TKA were significantly more likely (p < 0.05) to be younger, male, healthier, and from a higher socioeconomic status and to have undergone the procedure with a higher-volume surgeon. Over 95% of short-stay cases were successfully matched to longer-stay cases, and we found no significant difference in complications, health-care utilization, and costs between patients on the basis of the length of stay.

CONCLUSIONS

Patients undergoing short-stay THA or TKA with a discharge home were more likely to be younger, healthy, male patients from a higher socioeconomic status. Higher-volume surgeons are also more likely to perform short-stay THA or TKA. These characteristics confirm the previously held belief that a selection bias exists when comparing cohorts based on time to discharge. When comparing matched cohorts of patients who underwent short-stay and longer-stay THA or TKA, we observed no difference in outcomes, suggesting that a short stay with a discharge home in the appropriately selected patient is safe following THA or TKA.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Association between same day discharge total knee and total hip arthroplasty and risks of cardiac/pulmonary complications and readmission: a population-based observational study

OBJECTIVE

To determine if same-day discharge total knee arthroplasty (TKA) or total hip arthroplasty (THA) is not associated with increased risk of unplanned readmission and adverse outcomes within 30 days of surgery.

DESIGN

This is a population-based observational study.

SETTING

Patients from 708 participating institutions who underwent primary TKA or primary THA between 2011 and 2017 were divided into three groups by length of stay (LOS 0, 1 and 2-3 days). All patients with LOS>3 days were excluded from the current study. Regression analysis and propensity score matching were performed.

DATA SOURCES

American College of Surgeons-National Surgical Quality Improvement Programme database.

MAIN OUTCOMES AND MEASURES

Primary outcomes included unplanned readmission and cardiac/pulmonary complications within 30 days of surgery.

RESULTS

We identified 226 481 TKA (LOS 0=3118, LOS 1=31 404, and LOS 2-3=1 91 959) and 140 557 THA patients (LOS 0=2652, LOS 1=29 617, and LOS 2-3=1 08 288). There were no differences in 30-day mortality. After adjusting for relevant covariates, LOS 0 (compared with LOS 1) was associated with higher odds of cardiac/pulmonary complications in both TKA (OR 1.95, 95% CI 1.20 to 3.16; 0.67% vs 0.37%) and THA (OR 1.96, 95% CI 1.05 to 3.64; 0.57% vs 0.26%). There were no statistical differences in unplanned readmissions between LOS 0 and LOS 1 groups in TKA (2.41% vs 2.31%) and THA (1.62% vs 2.04%).

CONCLUSIONS

LOS 0 discharge after TKA and THA was associated with higher odds of cardiac/pulmonary complications compared with LOS 1 discharge. While the overall burden of complications is relatively low, until future studies can confirm or challenge our findings, a measured approach is advisable when recommending discharge of patients on the same day of surgery.

Low Rates of Adverse Events Following Ambulatory Outpatient Total Hip Arthroplasty at a Free-Standing Surgery Center

BACKGROUND

We proposed to determine the complication and hospital admission rates for patients with total hip arthroplasty (THA) done by a single surgeon in a stand-alone ambulatory surgical center with same-day discharge. Given the recent emphasis on bundled payments for a 90-day episode of care, this same time frame after surgery was chosen to determine patient outcomes.

METHODS

The records of patients with THAs done through a direct anterior approach by a single surgeon at 2 separate ambulatory surgery centers were reviewed. To analyze the learning curve for outpatient THA, the procedures were arbitrarily divided into 2 groups depending on when they were done: early in our experience or later. Complications were recorded, as were hospital admissions and surgical interventions, length of surgery and blood loss, and time spent at the outpatient facility.

RESULTS

Over a 3-year period, 145 outpatient THAs were done in 125 patients; 73 were considered to be initial procedures, and 72 were considered to be later procedures. Only one of the 145 procedures (0.7%) required transfer from the outpatient facility to the hospital for a blood transfusion. No other direct admissions to the hospital or transfers to the emergency department from the surgery center were necessary. Surgical interventions were required after 3 (2%) of the 145 arthroplasties in the global period (90 days).

CONCLUSION

This study demonstrated that same-day discharge to home following THA can be safely done without increased complications, readmissions, reoperations, or emergency room visits.

Primary Total Hip Arthroplasty With Same-Day Discharge: Who Failed and Why

As the emphasis on value-based care within total joint arthroplasty increases, this procedure is becoming more prevalent in the outpatient setting. The goals of this study were to report on the authors' early experiences with same-day discharge and to identify patient characteristics that are associated with failure to discharge after total hip arthroplasty within this program. All patients who were enrolled in the same-day discharge total hip arthroplasty program at the study institution between January 2015 and July 2016 were included. Demographics, baseline characteristics, and clinical and quality outcomes were compared between patients who successfully completed this program and those who did not. Of the 163 study subjects, 143 (87.7%) were discharged successfully on the same day as surgery. Women, patients younger than 40 years, and patients older than 60 years all had an increased risk of failing the program. Body mass index of 26 kg/m² or less was associated with a 40% greater risk of failure. Patients with an American Society of Anesthesiologists score of 3 had a 3-fold risk of failure compared with patients with an American Society of Anesthesiologists score of 2 or less. The screening protocol for same-day discharge at the study institution had an 87.7% rate of successful same-day discharge. Further investigation is needed to identify patients who are at risk of failing the same-day discharge initiative. [Orthopedics. 2018; 41(1):35-42.].

Total Hip Arthroplasty in the Outpatient Setting: What You Need to Know (Part 1)

The method by which surgeons conduct outpatient total hip arthroplasty (THA) procedures has yet to be fully standardized. Careful examination of components involved in the preoperative phase of outpatient hip arthroplasty procedures may lead to improved outcomes. This article will discuss methods for implementing successful outpatient THA protocols. Specifically it reviews information regarding patient selection criteria, preoperative education, and preoperative medical optimization.

Same-Day Discharge Compared with Inpatient Hospitalization Following Hip and Knee Arthroplasty

BACKGROUND

Discharge from the hospital on the day of (same-day) hip and knee arthroplasties has become more common; however, to our knowledge, few studies have compared morbidity between same-day and inpatient surgical procedures. The aims of this study were to compare matched cohorts of patients who underwent same-day and inpatient hip or knee arthroplasty in terms of postoperative complications and 30-day readmission rates.

METHODS

Patients who underwent primary elective total hip arthroplasty, total knee arthroplasty, or unicompartmental knee arthroplasty from 2005 to 2014 were identified from the National Surgical Quality Improvement Program registry. Patients discharged the day of the surgical procedure were matched 1:1 with patients who had an inpatient stay using propensity scores. The rates of 30-day adverse events and readmission were compared between matched cohorts using the McNemar test. Risk factors for 30-day readmission following same-day procedures were identified using multivariate regression.

RESULTS

Of 177,818 patients identified, 1,236 (0.70%) underwent a same-day surgical procedure. After matching, there were no differences in overall adverse events or readmission between same-day and inpatient groups, although inpatients had increased thromboembolic events (p = 0.048) and same-day patients had an increased rate of return to the operating room (p = 0.016). When procedures were assessed individually, the only difference identified was that the same-day total knee arthroplasty cohort had an increased return to the operating room compared with the inpatient total knee arthroplasty cohort (p = 0.046). Body mass index of ≥35 kg/m (p = 0.035), insulin-dependent diabetes (p = 0.041), non-insulin-dependent diabetes (p = 0.013), and age of ≥85 years (p = 0.039) were associated with 30-day readmission following same-day surgical procedures. Infection was the most common reason for reoperation and readmission following same-day procedures.

CONCLUSIONS

No significant differences in overall postoperative complications or readmission were found between matched cohorts of patients who underwent same-day and inpatient hip and knee arthroplasties, although inpatients had a higher rate of thromboembolic events and same-day patients had a higher rate of reoperation. Patients with a body mass index of ≥35 kg/m, diabetes, and an age of ≥85 years had an increased risk of 30-day readmission following same-day procedures, which was most commonly due to infection.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Rapid Discharge to Home After Total Knee Arthroplasty Is Safe in Eligible Medicare Patients

BACKGROUND

This study was aimed at assessing the risk of readmission for Medicare patients discharged home within a day of total knee arthroplasty (TKA) compared to those discharged on day 2 or beyond in a community medical center.

METHODS

A hospital inpatient database was queried for all unilateral, primary TKAs performed on patients 65 years or older from January 1, 2013, to December 31, 2015. A total of 2287 patients met the study criteria, of which 1502 were discharged within a day (short stay), and 785 were discharged on day 2 or beyond (traditional stay). The main outcome measures were all-cause 30-day and unplanned 90-day readmissions.

RESULTS

Short-stay patients did not experience a higher 30-day readmission rate (1.1%) compared to the traditional-stay patients (2.7%), nor did they experience a higher rate of unplanned 90-day readmissions (1.7% vs 3.6%). The short-stay group had more favorable demographics compared to the traditional-stay group. Logistic regression results revealed that none of the demographic factors considered had a statistically significant impact on 30-day readmission odds for either group. For unplanned 90-day readmissions, the results showed that for the short-stay patients, with the exception of age, none of the other demographic factors had significant impact on readmission odds and none were significant for the traditional-stay group.

CONCLUSION

Our results suggest that the Medicare patients meeting discharge criteria and discharged home within a day of TKA do not have an increased risk of 30-day and 90-day readmission.

Patient selection criteria for outpatient joint arthroplasty

PURPOSE

General consensus of patient selection criteria for outpatient joint arthroplasty is lacking, which is paramount to prevent prolonged hospital stay, adverse events and/or readmissions. This review highlights patient selection criteria for OJA based on the current literature and expert opinion.

METHODS

A search of the English and International electronic healthcare databases including MEDLINE/PubMed, EMBASE, AMED and the Cochrane library was performed in November 2015 to include studies published during the last 10 years. Furthermore, a survey of physicians from different specialties was performed.

RESULTS

Fourteen studies described results regarding outpatient joint arthroplasty. Studies on outpatient hip and/or knee arthroplasty resulted in similar outcome in preselected patients. Patients who are able and willing to participate, with a low ASA classification (<III), undergoing primary arthroplasty, age <75 and with support at home during the first postoperative days are eligible candidates for outpatient joint arthroplasty. Patients with a high ASA classification (>II), bleeding disorders, poorly controlled and/or severe cardiac (e.g. heart failure, arrhythmia) or pulmonary (e.g. embolism, respiratory failure) comorbidities, uncontrolled DM (type I or II), a high BMI (>30 m²/kg), chronic opioid consumption, functional neurological impairments, dependent functional status, chronic/end-stage renal disease and/or reduced preoperative cognitive capacity should be excluded from outpatient joint arthroplasty. The expert opinion-based selection criteria were comparable to literature with a further extension of exclusion for patients with practical issue's, urologic medical history and/or severe mobility disorders.

CONCLUSION

Based on the current literature, the presented patient selection criteria provide a basis for outpatient joint arthroplasty and can be useful when selecting patients. Together with a change in mindset, a multidisciplinary approach and literature-based protocols, outpatient joint arthroplasty can be applied in daily orthopaedic practice while ensuring patients' safety.

LEVEL OF EVIDENCE

Clinical review, Level III.

Late Complications Following Elective Primary Total Hip and Knee Arthroplasty: Who, When, and How?

BACKGROUND

Improved pain management and early mobilization protocols have increased interest in the feasibility of short stay (<24 hours) or outpatient total hip (THA) and total knee (TKA) arthroplasty. However, concerns exist regarding patient safety and readmissions. The purposes of this study were to determine the incidence of in-hospital complications following THA/TKA, to create a model to identify comorbidities associated with the risk of developing major complications >24 hours postoperatively, and to validate this model against another consecutive series of patients.

METHODS

We prospectively evaluated a consecutive series of 802 patients who underwent elective primary THA and TKA over a 9-month period. The mean age was 62.3 years. Demographic, surgical, and postoperative readmission data were entered into an arthroplasty database.

RESULTS

Of the 802 patients, 382 experienced a complication postoperatively. Of these, 152 (19%) required active management. Multiple logistic regression analysis identified cirrhosis (odds ratio [OR], 5.89; 95% confidence interval [CI], 1.05-33.07; P = .044), congestive heart failure (OR, 3.12; 95% CI, 1.50-6.44; P = .002), and chronic kidney disease (OR, 3.85; 95% CI, 2.21-6.71; P < .001) as risk factors for late complications. One comorbidity was associated with a 77% probability of developing a major postoperative complication. This model was validated against an independent dataset of 1012 patients.

CONCLUSION

With improved pain management and mobilization protocols, there is increasing interest in short stay and outpatient THA and TKA. Patients with cirrhosis, congestive heart failure, or chronic kidney disease should be excluded from early discharge total joint arthroplasty protocols.

The Prevalence of Diabetes Mellitus and Routine Hemoglobin A1c Screening in Elective Total Joint Arthroplasty Patients

BACKGROUND

Diabetes mellitus has been associated with significant perioperative complications in joint arthroplasty. In addition, many patients are unaware of their dysglycemic status, and the prevalence of undiagnosed dysglycemia in joint arthroplasty patients is unknown.

METHODS

Several years ago, we began routine hemoglobin A1c (HbA1c) level screening in all our patients planning to undergo elective total hip and total knee arthroplasties. We retrospectively reviewed the HbA1c levels in our initial 663 patients.

RESULTS

Forty-eight percent of these patients were found to be nondiabetic; 19% percent had a previous history of some level of dysglycemia. Most significantly, over one third, 33.6% of these patients were previously undiagnosed dysglycemic patients; 31% were diagnosed as prediabetic and 2.6% as diabetic.

CONCLUSION

Owing to the high prevalence of prediabetic patients who go on to develop diabetes and to the high correlation of poor glucose control with perioperative complications, we feel that it is imperative to identify this large number of previously undiagnosed dysglycemic patients. We recommend the routine screening of all patients planning to undergo major orthopedic procedures. Likewise, we recommend that identified patients be referred for diabetic counseling. We also recommend that patients with markedly elevated HbA1c levels have their elective surgery postponed until better glycemic control can be achieved.