Analysis of 90-Day Readmissions After Total Shoulder Arthroplasty

Identifying risk factors for 30-day readmission after outpatient total shoulder arthroplasty to aid in patient selection

Background

A recent meta-analysis comparing inpatient and outpatient total shoulder arthroplasty (TSA) showed no statistically significant differences in complications, readmissions, revisions, and infections. However, there remains no research on the appropriate patient selection for outpatient TSA surgeries. This retrospective review seeks to aid surgeons in refining a safe patient selection algorithm by evaluating risk factors through a large database analysis of TSA surgeries.

Methods

Patients who underwent TSA between 2015 and 2020 were identified in the National Surgical Quality Improvement Program database. Patients with a hospital stay of 0 days were designated as outpatient procedures. Multivariate analyses were used to determine risk factors for 30-day readmission following outpatient TSA and whether risk factors remained significant following overnight hospital stay.

Results

A total of 2431 outpatient TSA patients were identified. The incidence of 30-day readmission was 1.8%. The majority of readmissions were due to pulmonary complications. The clinically significant risk factors for 30-day readmission were chronic steroid use (odds ratio [OR] 3.55, 95% confidence interval [CI] 1.34-9.43; P = .011), chronic obstructive pulmonary disease (COPD) (OR 3.11, 95% CI 1.16-8.34; P = .024), and current smoking status (OR 2.27, 95% CI 1.02-5.03; P = .045). After overnight hospital stay, chronic steroid use and current smoking status were not significant, but COPD remained significant.

Conclusion

Patients with chronic steroid use, COPD, or current smoking status are at increased risk for 30-day readmission. Inpatient hospital stay appears to benefit patients with chronic steroid use and current smoking status. Patients with COPD should be admitted for inpatient stay postoperatively but may still have high 30-day readmission rates following discharge.

Perioperative Outcomes, Comorbidities, and Complications following Total Shoulder Arthroplasty in Wheelchair Users: A Retrospective Cohort Analysis of a Nationwide Database

Impaired shoulder function hinders the ability of wheelchair users to maintain independence. The current state of the literature delineates the risks and benefits of surgical techniques for the management of shoulder pathologies. To the best of our knowledge, there is no study that has investigated complications following total shoulder arthroplasty (TSA) in wheelchair users. Utilizing the PearlDiver Mariner national administrative database, 72,108 patients were identified who underwent TSA with a concurrent diagnosis of a rotator cuff tear. Two matched cohorts, one of wheelchair users and one of non-wheelchair users, were created. Due to limitations within PearlDiver, one-year outcomes, including comorbidity and complication rates and readmission statistics, were compared between the two cohorts. Each matched cohort of 869 patients underwent TSA with a concurrent diagnosis of a rotator cuff tear. The rate of readmission in wheelchair users was greater than in non-wheelchair users (24.05% vs. 9.55%, OR: 3.00, CI: 2.279, 3.946). Patients in the wheelchair cohort exhibited higher rates of complications and comorbidities (p < 0.001). Among the most likely to be readmitted after TSA were patients with osteoarthritis, pulmonary heart disease, rheumatoid arthritis, and hypertension (p < 0.05). Significant differences in surgical outcomes existed between wheelchair and non-wheelchair users in terms of preoperative comorbidities, postoperative complications, and readmission rates.

Utilization of comorbidity indices to predict discharge destination and complications following total shoulder arthroplasty

Background

Comorbidity indices can help identify patients at risk for postoperative complications. Purpose of this study was to compare different comorbidity indices to predict discharge destination and complications after shoulder arthroplasty.

Methods

Retrospective review of institutional shoulder arthroplasty database of primary anatomic (TSA) and reverse (RSA) shoulder arthroplasties. Patient demographic information was collected in order to calculate Modified Frailty Index (mFI-5), Charlson Comorbidity Index (CCI), age adjusted CCI (age-CCI), and American Society of Anesthesiologists physical status classification system (ASA). Statistical analysis performed to analyze length of stay (LOS), discharge destination, and 90-day complications.

Results

There were 1365 patients included with 672 TSA and 693 RSA patients. RSA patients were older and had higher CCI, age adjusted CCI, ASA, and mFI-5 (p < 0.001). RSA patients had longer lengths of stay (LOS), more likely to have an adverse discharge (p < 0.001), and higher reoperation rate (p = 0.003). Age-CCI was most predictive of adverse discharge (AUC 0.721, 95% CI 0.704-0.768).

Discussion

Patients undergoing RSA had more medical comorbidities, experienced greater LOS, higher reoperation rate, and were more likely to have an adverse discharge. Age-CCI had the best ability to predict which patients were likely to require higher-level discharge planning.

Effects of Patient Comorbidities and Demographics on Episode-of-Care Costs Following Total Shoulder Arthroplasty

BACKGROUND

As demand for shoulder arthroplasty grows, adequate cost containment is of importance. Given the historical use of bundle payments for lower extremity arthroplasty, it is reasonable to anticipate that such programs will be universally implemented in shoulder arthroplasty. This project evaluates how patient demographics, medical comorbidities, and surgical variables affect episode-of-care costs in an effort to ensure accurate reimbursement scales and equitable access to care.

METHODS

Consecutive series of primary total shoulder arthroplasty (anatomic and reverse) procedures were retrospectively reviewed at a single academic institution from 2014 to 2020 using claims cost data from Medicare and a private insurer. Patient demographics, comorbidities, and clinical outcomes were collected. A stepwise multivariate regression was performed to determine the independent effect of comorbidities and demographics on 90-day episode-of-care costs.

RESULTS

Overall, 1,452 shoulder arthroplasty patients were identified (1,402 Medicare and 50 private payer patients). The mean 90-day cost for Medicare and private payers was $25,822 and $31,055, respectively. Among Medicare patients, dementia ($3,407, P = 0.003), history of stroke ($3,182, P = 0.005), chronic pulmonary disease ($1,958, P = 0.007), anemia ($1,772, P = 0.039), and heart disease ($1,699, P = 0.014) were associated with significantly increased costs. Demographics that significantly increased costs included advanced age ($199 per year in age, P < 0.001) and elevated body mass index ($183 per point, P < 0.001). Among private payers, hyperlipidemia ($6,254, P = 0.031) and advanced age ($713 per year, P < 0.001) were associated with an increase in total costs.

CONCLUSION

Providers should be aware that certain demographic variables and comorbidities (history of stroke, dementia, chronic pulmonary disease, anemia, heart disease, advanced age, and elevated body mass index) are associated with an increase in total costs following primary shoulder arthroplasty. Further study is required to determine whether bundled payment target costs should be adjusted to better compensate for specific comorbidities.

LEVEL OF EVIDENCE

Level IV case series.

Incidence and 30- and 90-day readmission rates after primary shoulder arthroplasty in the United States: an analysis using the National Readmissions Database

BACKGROUND

The field of shoulder arthroplasty has experienced a substantial increase in the number of procedures performed annually and a shift toward more common implantation of reverse shoulder arthroplasties (RSAs). Same-day discharge is perceived as beneficial for most patients as well as our health care system, and the number of shoulder procedures performed as same-day surgery has increased substantially. However, the potential benefits of same-day discharge after shoulder arthroplasty may be negatively influenced by unexpected readmissions. As such, an in-depth analysis of readmission rates after primary shoulder arthroplasty is particularly timely.

METHODS

The National Readmissions Database was queried for primary shoulder arthroplasty procedures performed in the United States between 2016 and 2018. National incidences were calculated, and indications, patient demographic characteristics, comorbidities, facility characteristics, and rates and causes of 30- and 90-day readmissions were determined for all procedures and compared between anatomic total shoulder arthroplasty (TSA), anatomic hemiarthroplasty (HA), and RSA.

RESULTS

During the study period, 336,672 primary shoulder arthroplasties were performed (37% TSAs, 57% RSAs, and 6% HAs). In 2018, national incidences per 100,000 inhabitants were 22.64 for RSA, 12.70 for TSA, and 1.50 for HA. The utilization of these procedures between 2016 and 2018 increased for RSA, decreased for HA, and remained constant for TSA, but these changes did not reach the level of statistical significance. The average all-cause 30-day readmission rates were 3.63%, 1.92%, and 3.81% for RSA, TSA, and HA, respectively, and the average all-cause 90-day readmission rates were 7.76%, 4.37%, and 9.18%, respectively. For both RSA and HA, the most common surgical diagnosis for 30-day and 90-day readmissions was dislocation (0.45% and 0.99%, respectively, for RSA and 0.21% and 0.67%, respectively, for HA). For TSA, the most common surgical diagnosis for 30-day readmission was infection (0.11%); however, this was surpassed by dislocation (0.28%) at 90 days.

CONCLUSION

RSA surpassed TSA as the most frequently performed shoulder arthroplasty procedure in the United States between 2016 and 2018. During this period, the 90-day readmission rate was not negligible, with dislocation and infection as the leading orthopedic causes of readmission.

Prediction of total healthcare cost following total shoulder arthroplasty utilizing machine learning

BACKGROUND

Given the increase in demand in treatment of glenohumeral arthritis with anatomic total (aTSA) and reverse shoulder arthroplasty (RTSA), it is imperative to improve quality of patient care while controlling costs as private and federal insurers continue its gradual transition toward bundled payment models. Big data analytics with machine learning shows promise in predicting health care costs. This is significant as cost prediction may help control cost by enabling health care systems to appropriately allocate resources that help mitigate the cause of increased cost.

METHODS

The Nationwide Readmissions Database (NRD) was accessed in 2018. The database was queried for all primary aTSA and RTSA by International Classification of Diseases, Tenth Revision (ICD-10) procedure codes: 0RRJ0JZ and 0RRK0JZ for aTSA and 0RRK00Z and 0RRJ00Z for RTSA. Procedures were categorized by diagnoses: osteoarthritis (OA), rheumatoid arthritis (RA), avascular necrosis (AVN), fracture, and rotator cuff arthropathy (RCA). Costs were calculated by utilizing the total hospital charge and each hospital's cost-to-charge ratio. Hospital characteristics were included, such as volume of procedures performed by the respective hospital for the calendar year and wage index, which represents the relative average hospital wage for the respective geographic area. Unplanned readmissions within 90 days were calculated using unique patient identifiers, and cost of readmissions was added to the total admission cost to represent the short-term perioperative health care cost. Machine learning algorithms were used to predict patients with immediate postoperative admission costs greater than 1 standard deviation from the mean, and readmissions.

RESULTS

A total of 49,354 patients were isolated for analysis, with an average patient age of 69.9 ± 9.6 years. The average perioperative cost of care was $18,843 ± $10,165. In total, there were 4279 all-cause readmissions, resulting in an average cost of $13,871.00 ± $14,301.06 per readmission. Wage index, hospital volume, patient age, readmissions, and diagnosis-related group severity were the factors most correlated with the total cost of care. The logistic regression and random forest algorithms were equivalent in predicting the total cost of care (area under the receiver operating characteristic curve = 0.83).

CONCLUSION

After shoulder arthroplasty, there is significant variability in cumulative hospital costs, and this is largely affected by readmissions. Hospital characteristics, such as geographic area and volume, are key determinants of overall health care cost. When accounting for this, machine learning algorithms may predict cases with high likelihood of increased resource utilization and/or readmission.

Total Shoulder Arthroplasty: Antibiotic Allergies Increase Risk of Postoperative Complications

BACKGROUND

Periprosthetic infections after total shoulder arthroplasty (TSA) are associated with devastating complications and prolonged treatment. Patients with identified antibiotic allergy (ABX) may be at increased risk for complications because of suboptimal preincisional prophylaxis. This study aims to quantify the risk of postoperative outcomes and complications for patients undergoing TSA with a history of ABX.

METHODS

Retrospective cohort analysis of patient data was conducted using the PearlDiver Patient Records Database. Patients who underwent TSA for osteoarthritis were identified using Current Procedural Terminology and International Classification of Diseases codes and were stratified based on self-reported (1) penicillin, (2) sulfonamide, or (3) other antibiotic allergies. We analyzed patient demographics, comorbidities, 90-day medical complications, and rate of revision at 30 days, 90 days, 1 year, and 2 years.

RESULTS

In total, 85,606 patients who underwent TSA for osteoarthritis from 2010 to 2018 were identified, of whom 7,836 (9.15%) had a reported ABX. Univariate analysis found the ABX cohort was younger (67.5 versus 67.7 year; P = 0.042), more often female (67.57% versus 54.79%; P < 0.001), and more likely to have Elixhauser comorbidities than nonallergic control subjects. Multivariate analysis found patients who reported ABX had increased likelihood of periprosthetic joint infection (PJI) within 30 days (odds ratio [OR]: 3.129), 1 year (OR: 2.016), and 2 years of surgery (OR: 2.221). Patients with reported ABX had increased likelihood of postoperative anemia (OR: 1.126), blood transfusion (OR: 1.238), and readmission (OR: 1.585) within 90 days of surgery. Patients with penicillin allergy had a greater incidence of revision due to PJI at 30 days (OR: 4.811), 90 days (OR: 2.91), 1 year (OR: 2.105), and 2 years (OR: 2.72). Rates of reported ABX increased from 2010 to 2018 (8.60% to 10.91%; P = 0.001) in patients undergoing TSA.

CONCLUSION

Patients undergoing TSA with a history of ABX had a higher risk of readmission, postoperative anemia, blood transfusions, and PJI. These findings support critical assessment and clarification of reported allergies before TSA and possibly the use of preoperative allergy testing.

LEVEL OF EVIDENCE

Level 3 therapeutic study.

Chronic steroid use and readmission following total shoulder arthroplasty

Background

Degenerative arthritis is a major indication for both anatomic and reverse total shoulder arthroplasty (TSA). Degenerative arthritis is an age-related process that can be secondary to mechanical wear or inflammatory or autoimmune diseases, such as rheumatoid arthritis or systemic lupus erythematosus. Management of these diseases can include chronic corticosteroid for their anti-inflammatory and immunosuppressive effects. Given the well-known complications of chronic steroid use on other surgical procedures, investigation into postoperative complications specific to TSA will assist physicians in risk stratification and preoperative planning. The purpose of this study was to investigate the association between chronic preoperative steroid use and postoperative complications following TSA.

Methods

The American College of Surgeons National Surgical Quality Improvement database was queried for all patients who underwent TSA between 2015 and 2020. Patient demographics, comorbidities, surgical characteristics, and 30-day postoperative complication data were collected. Multivariate logistic regression was used to identify postoperative complications associated with chronic preoperative steroid use. Reasons and risk factors for readmission among chronic steroid users were subsequently identified, as well.

Results

A total of 26,669 patients were included in this study: 25,376 (95.2%) were included in the nonsteroid cohort and 1293 (4.8%) were included in the chronic steroid cohort. The postoperative complications that were significantly associated with chronic preoperative steroid use were septic shock (P = .007), urinary tract infection (P = .016), myocardial infarction (P = .022), ventilator >48 hours (P = .028), readmission (P < .001), nonhome discharge (P < .001), and mortality (P = .007). The only postoperative complication independently associated with chronic preoperative steroid use was readmission (odds ratio, 1.36; 95% confidence interval, 1.04-1.79; P = .027).

Conclusion

Preoperative chronic steroid use is an independent predictor for readmission following TSA. As procedural improvement increases surgical volume for TSA, a better understanding of preoperative risk factors can improve perioperative risk stratification and help to minimize adverse outcomes.

Comparison of patient-demographics, causes, and costs of 90-day readmissions following primary total shoulder arthroplasty for glenohumeral osteoarthritis

Introduction

Readmissions following orthopaedic surgery are associated with worse outcomes and increased healthcare costs. Studies investigating trends, causes, and costs of readmissions following primary total shoulder arthroplasty (TSA) for the indication of glenohumeral osteoarthritis (OA) are limited. The objective was to compare: 1) patient-demographics of those readmitted and not readmitted within 90-days following primary TSA for OA; 2) causes of readmissions and 3) associated costs.

Methods

A retrospective query from 2005 to 2014 was performed using a nationwide administrative claims database. The study group consisted of patients readmitted within 90-days following primary TSA for glenohumeral OA, whereas patients not readmitted served as controls. Causes of readmission were stratified into the following groups: cardiovascular, hematological, endocrine, gastrointestinal (GI), musculoskeletal (MSK), neoplastic, neurological, pulmonary, infectious, renal, and miscellaneous causes. Patient demographics were compared, in addition to the frequency of the causes of readmissions, and their associated costs. Chi-square analyses compared demographics between groups. Analysis of variance was utilized to determine differences in 90-day costs for the causes of readmission. A p-value less than 0.001 was significant.

Results

The overall 90-day readmission rate was 2.4% (3432/143,878). Patients readmitted following primary TSA were more likely to be over the age of 75, female, and higher prevalence of comorbid conditions, including psychiatric and medical conditions. Readmitted patients had a higher overall comorbidity burden per mean Elixhauser-Comorbidity Index (ECI) scores (10 vs. 7,p < .0001). The leading cause of readmissions were due to MSK (17.34%), cardiac (16.28%), infectious (16.26%), and gastrointestinal (11.64%) etiologies. There were differences in the mean 90-day costs of care for the various causes of readmissions, with the leading cost of readmissions being cardiac causes ($10,913.70) and MSK ($10,590.50) etiologies.

Conclusion

Patients with greater comorbidities experienced increased incidence of readmission following TSA for glenohumeral OA. Cardiac and MSK etiologies were the primary cause of readmissions.

Level of evidence

III.

Prior Nonshoulder Periprosthetic Joint Infection Increases the Risk of Surgical Site Infection, Sepsis, and All-Cause Revision After Primary Total Shoulder Arthroplasty

INTRODUCTION

Periprosthetic joint infection (PJI) after total joint arthroplasty is a known risk factor for infection in subsequent joint arthroplasty. The purpose of this study was to determine whether prior nonshoulder PJI contributes to the increased risk of infectious complications, greater healthcare utilization, and increased revision surgery after primary total shoulder arthroplasty (TSA).

METHODS

Patients who underwent primary TSA for osteoarthritis with prior nonshoulder PJI were identified in a national database (PearlDiver Technologies) using Current Procedural Terminology and International Classification of Diseases codes. These patients were propensity matched based on age, sex, Charlson Comorbidity Index, smoking status, and obesity (body mass index >30 kg/m2) to a control cohort of patients who underwent primary TSA for osteoarthritis without any prior PJI. Primary outcomes include 1- and 2-year revision rates. Secondary outcomes include healthcare-specific outcomes of readmission, emergency department visits, length of stay, and mortality. Bivariate analysis was conducted using chi-square tests to compare all outcomes and complications between both cohorts.

RESULTS

Compared with patients without prior PJI, those with prior PJI had a significantly higher risk of 90-day surgical site infection (7.61% versus 0.56%) and sepsis (1.79% versus 0.56%) after TSA (P < 0.05 for both). Patients with prior PJI also had a higher risk of 90-day readmission compared with those without prior PJI (3.36% versus 1.23%, P = 0.008). In terms of surgical complications, patients with prior PJI had significantly higher risk of 2-year revision surgery compared with patients without prior PJI (3.36% versus 1.57%, P = 0.034).

CONCLUSION

Prior nonshoulder PJI of any joint increases rates of 90-day surgical site infection, sepsis, and hospital readmission, as well as 2-year all-cause revision after TSA. These results are important for risk-stratifying patients undergoing TSA with prior history of PJI.

LEVEL OF EVIDENCE

III.

Characteristics and risk factors for 90-day readmission following shoulder arthroplasty

BACKGROUND

Anatomic total shoulder arthroplasty (TSA) and reverse TSA are the standard of care for end-stage shoulder arthritis. Advancements in implant design, perioperative management, and patient selection have allowed shorter inpatient admissions. Unplanned readmissions remain a significant complication. Identification of risk factors for readmission is prudent as physicians and payers prepare for the adoption of bundled care reimbursement models. The purpose of this study was to identify characteristics and risk factors associated with readmission following shoulder arthroplasty using a large, bi-institutional cohort.

METHODS

A total of 2805 anatomic TSAs and 2605 reverse TSAs drawn from 2 geographically diverse, tertiary health systems were examined for unplanned inpatient readmissions within 90 days following the index operation (primary outcome). Forty preoperative patient sociodemographic and comorbidity factors were tested for their significance using both univariable and multivariable logistic regression models, and backward stepwise elimination selected for the most important associations for 90-day readmission. Readmissions were characterized as either medical or surgical, and subgroup analysis was performed. A short length of stay (discharge by postoperative day 1) and discharge to a rehabilitation or skilled nursing facility were also examined as secondary outcomes. Parameters associated with increased readmission risk were included in a predictive model.

RESULTS

Within 90 days of surgery, 175 patients (3.2%) experienced an unanticipated readmission, with no significant difference between institutions (P = .447). There were more readmissions for surgical complications than for medical complications (62.9% vs. 37.1%, P < .001). Patients discharged to a rehabilitation or skilled nursing facility were significantly more likely to be readmitted (13.1% vs. 8.8%, P = .049), but a short inpatient length of stay was not associated with an increased rate of 90-day readmission (42.9% vs. 41.3%, P = .684). Parameter selection based on predictive ability resulted in a multivariable logistic regression model composed of 16 preoperative patient factors, including reverse TSA, revision surgery, right-sided surgery, and various comorbidities. The area under the receiver operator characteristic curve for this multivariable logistic regression model was 0.716.

CONCLUSION

Risk factors for unplanned 90-day readmission following shoulder arthroplasty include reverse shoulder arthroplasty, surgery for revision and fracture, and right-sided surgery. Additionally, there are several modifiable and nonmodifiable risk factors that can be used to ascertain a patient's readmission probability. A shorter inpatient stay is not associated with an increased risk of readmission, whereas discharge to post-acute care facilities does impose a greater risk of readmission. As scrutiny around health care cost increases, identifying and addressing risk factors for readmission following shoulder arthroplasty will become increasingly important.