Age, race, comorbidity, and insurance payer type are associated with outcomes after total ankle arthroplasty.

OBJECTIVE: To assess whether age, race/ethnicity, comorbidity, and insurance payer status are associated with outcomes after total ankle arthroplasty (TAA). METHODS: Using the US National Inpatient Sample (NIS) data and multivariable-adjusted logistic regression, we assessed the association of age, race/ethnicity, comorbidity ,and insurance payer status, with healthcare utilization and in-hospital complications (infection, transfusion, and revision surgery) after TAA. We calculated odds ratio (OR) and 95% confidence intervals (CI). RESULTS: The cohort consisted of 6280 TAAs with a mean age of 62 years; 52% were female, 70% White, and 62% had osteoarthritis as the underlying diagnosis. Compared to age < 50 years, older age categories had higher ORs of total hospital charges above the median, length of hospital stay above the median (>2 days) and discharge to a rehabilitation facility, 1.26-19.41, and a lower OR of in-hospital infection, 0.07-0.09. Compared to Whites, Blacks had higher OR (95% CI) of: discharge to a rehabilitation facility, 1.45 (1.06, 1.98); length of hospital stay >2 days, 2.21 (1.37, 3.57); in-hospital transfusion, 4.39 (1.87, 10.30); and in-hospital revision, 8.25 (1.06, 64.21); and Hispanics were more likely to have total hospital charges above the median, OR 1.49 (1.10, 2.02), and infection, 9.30 (1.27, 68.05). Higher comorbidity and Medicare payer status were each associated with higher ORs of healthcare utilization, ORs ranging 1.20-2.57 and 1.74-2.19, respectively. CONCLUSIONS: Age, race/ethnicity, comorbidity, and insurance payer status were independently associated with post-TAA outcomes. Further insight into modifiable mediators of these associations can pave the way for improving these outcomes in the future.Key Points• Older age was associated with higher healthcare utilization post-ankle arthroplasty.• Compared to Whites, Blacks or Hispanics had higher healthcare utilization and in-hospital complications post-ankle arthroplasty.• Higher comorbidity and Medicare payer status were each associated with higher healthcare utilization post-ankle arthroplasty.

Patients at Risk for Exceeding CJR Cost Targets After Total Ankle Arthroplasty.

BACKGROUND: The Comprehensive Care for Joint Replacement (CJR) model includes total ankle arthroplasty (TAA), under which a target reimbursement is established. Whether this reimbursement is sufficient to cover average cost remains unknown. We hypothesized that a substantial number of TAAs still exceed cost targets, and that risk factors associated with exceeding the target cost could be identified preoperatively. METHODS: Two hundred two primary TAAs performed at a single tertiary referral center under the CJR model from June 2013 to May 2017 were retrospectively reviewed. Patient demographics, comorbidities, outcomes, and costs were extracted from the electronic medical record using a validated structured query language (SQL) algorithm. A comparison cohort of 2084 CJR total hip arthroplasty (THA) and total knee arthroplasty (TKA) cases performed during the same period was also reviewed. RESULTS: Twenty TAAs (10%) exceeded the target cost of care, significantly fewer than CJR THAs/TKAs (29%) performed during the same period (P < .0001). These patients did not differ significantly in age, sex, body mass index, number of Elixhauser comorbidities, or the American Society of Anesthesiologists score. The average cost for these patients was $17 338 higher than those who did not exceed the target cost, and they were less likely to be married or have a partner (45% vs 79%, P = .001). Non-Caucasian status also reached significance (P < .0001). Those exceeding the target cost had a significantly longer length of stay (2.6 vs 1.5 days, P < .0001) and were more likely to be discharged to either skilled nursing or a rehabilitation facility (60% vs 1%, P < .0001). CONCLUSION: Even high-volume TAA centers still exceed target costs in up to 10% of cases, with length of stay, discharge location, and readmissions driving many of these events. Potential risk factors for excess cost include marital/partner status and non-Caucasian ethnicity, but further work is needed to clarify their effects and whether other risk factors exist. LEVEL OF EVIDENCE: Level III, comparative study.

Blood Transfusion During Total Ankle Arthroplasty Is Associated With Increased In-Hospital Complications and Costs.

INTRODUCTION: Total ankle arthroplasty (TAA) is an increasingly used, effective treatment for end-stage ankle arthritis. Although numerous studies have associated blood transfusion with complications following hip and knee arthroplasty, its effects following TAA are largely unknown. This study uses data from a large, nationally representative database to estimate the association between blood transfusion and inpatient complications and hospital costs following TAA. METHODS: Using the Nationwide Inpatient Sample (NIS) database from 2004 to 2014, 25 412 patients who underwent TAA were identified, with 286 (1.1%) receiving a blood transfusion. Univariate analysis assessed patient and hospital factors associated with blood transfusion following TAA. RESULTS: Patients requiring blood transfusion were more likely to be female, African American, Medicare recipients, and treated in nonteaching hospitals. Average length of stay for patients following transfusion was 3.0 days longer, while average inpatient cost was increased by approximately 50%. Patients who received blood transfusion were significantly more likely to suffer from congestive heart failure, peripheral vascular disease, hypothyroidism, coagulation disorder, or anemia. Acute renal failure was significantly more common among patients receiving blood transfusion ( P < .001). CONCLUSION: Blood transfusions following TAA are infrequent and are associated with multiple medical comorbidities, increased complications, longer hospital stays, and increased overall cost. LEVELS OF EVIDENCE: Level III: Retrospective, comparative study.

Possible Implications for Bundled Payment Models of Comorbidities and Complications as Drivers of Cost in Total Ankle Arthroplasty.

BACKGROUND:: The Comprehensive Care for Joint Replacement (CJR) model provides bundled payments for in-hospital and 90-day postdischarge care of patients undergoing total ankle arthroplasty (TAA). Defining patient factors associated with increased costs during TAA could help identify modifiable preoperative patient factors that could be addressed prior to the patient entering the bundle, as well as determine targets for cost reduction in postoperative care. METHODS:: This study is part of an institutional review board-approved single-center observational study of patients undergoing TAA from January 1, 2012, to December 15, 2016. Patients were included if they met CJR criteria for inclusion into the bundled payment model. All Medicare payments beginning at the index procedure through 90 days postoperatively were identified. Patient, operative, and postoperative characteristics were associated with costs in adjusted, multivariable analyses. One hundred thirty-seven patients met inclusion criteria for the study. RESULTS:: Cerebrovascular disease (intracranial hemorrhages, strokes, or transient ischemic attacks) was initially associated with increased costs (mean, $5595.25; 95% CI, $1710.22-$9480.28) in adjusted analyses ( P = .005), though this variable did not meet a significance threshold adjusted for multiple comparisons. Increased length of stay, discharge to a skilled nursing facility (SNF), admissions, emergency department (ED) visits, and wound complications were significant postoperative drivers of payment. CONCLUSION:: Common comorbidities did not reliably predict increased costs. Increased length of stay, discharge to an SNF, readmission, ED visits, and wound complications were postoperative factors that considerably increased costs. Lastly, reducing the rates of SNF placement, readmission, ED visitation, and wound complications are targets for reducing costs for patients undergoing TAA. LEVEL OF EVIDENCE:: Level II, prognostic prospective cohort study.

Patient Risk Factors Do Not Impact 90-Day Readmission and Emergency Department Visitation After Total Ankle Arthroplasty: Implications for the Comprehensive Care for Joint Replacement (CJR) Bundled Payment Plan.

BACKGROUND: The Comprehensive Care for Joint Replacement (CJR) model provides bundled payments for in-hospital care and care within 90 days following discharge for Medicare beneficiaries undergoing lower-extremity joint replacement involving the hip, knee, or ankle (total hip arthroplasty, total knee arthroplasty, or total ankle arthroplasty [TAA]). The study hypothesis was that patient comorbidities are associated with readmissions, emergency department (ED) utilization, and subspecialist wound-healing consultation, which are examples of costly contributors to postoperative health-care spending. METHODS: The medical records for 1,024 patients undergoing TAAs between June 2007 and December 2016 at a single academic center in the southeastern United States were reviewed for the outcomes of readmissions, ED visitations, and subspecialist wound-healing consultation within the 90-day post-discharge period. All patients undergoing TAA (n = 1,365) were eligible. Of the 1,037 patients who consented to participation in the study and underwent TAA, 1,024 (98.7%) completed the study. Medical comorbidities according to the Elixhauser and Charlson-Deyo comorbidity indices that were present prior to TAA were recorded. Univariate and multivariable tests of significance were used to relate patient and operative characteristics to outcomes. RESULTS: Four hundred and ninety-six (48.4%) of the 1,024 patients were female, and 964 (94.1%) were white/Caucasian, with an average age (and standard deviation) of 63 ± 10.5 years. Hypertension, obesity, solid tumor, depression, rheumatic disease, cardiac arrhythmia, hypothyroidism, diabetes mellitus, and chronic pulmonary disease had a prevalence of >10%. Fifty-three (5.2%) of the 1,024 patients were readmitted for any cause. Thirty-six (3.5%) of the 1,024 returned to the ED but were not admitted to the hospital. Readmission or ED visitation was most commonly for a wound complication, followed by deep venous thrombosis (DVT) and pulmonary embolism (PE) evaluation, while urgent medical evaluations composed the majority of non-TAA-related ED visitations. No patient comorbidities were significantly associated with 90-day readmission, ED visitation, or wound complications in multivariable models. CONCLUSIONS: Patient comorbidities were not associated with 90-day hospital readmissions or ED visitation for patients undergoing TAA. Readmissions were dominated by evaluation of wound compromise as well as DVT and PE. These data suggest that there may be considerable differences between TAA and total hip arthroplasty or total knee arthroplasty that cause surgeons to question the inclusion of TAA in CJR bundled payment models. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Does Total Ankle Arthroplasty Belong in the Comprehensive Care for Joint Replacement?

The Comprehensive Care for Joint Replacement (CJR) model seeks to lower costs and improve quality for primary lower extremity joint replacements. This includes total ankle arthroplasty (TAA), which is performed far less frequently than total hip (THA) and knee (TKA) arthroplasty. We used the SPARCS database to identify 537 TAA and 239,053 elective primary THA or TKA procedures from 2009 to 2014, excluding hip fractures. Compared with THA and TKA, TAA had a shorter mean length of stay (2.2 versus 3.2 days), greater mean cost ($20,817 versus $17,613), lower rate of disposition to nursing and rehabilitation facilities (17% versus 52%), and lower rate of 90-day readmission (4.9% versus 5.8%). In multivariable-adjusted regression models of TAA versus THA and TKA, length of stay was 30% shorter (p < .001), costs were 14% greater (p < .001), and risk of disposition to nursing and rehabilitation facilities was 86% lower (p < .001), with no significant difference in 90-day readmission (p = .957). Patients undergoing TAA had different patterns of short-term resource usage compared with patients undergoing THA and TKA, most notably higher short-term costs. The economic viability of TAA is threatened by alternative payment models that reimburse hospitals for TAA at the same rate as THA and TKA.

Factors Contributing to Hospital Stay and Total Inpatient Charges in Total Ankle Arthroplasty: Review of the National Inpatient Sample.

Total ankle arthroplasty (TAA) is commonly performed for end-stage ankle osteoarthritis. Given rising costs and declining reimbursements, identifying variables increasing length of stay (LOS) and total inpatient charges (TICs) of TAA is necessary for providing cost-effective care. The National Inpatient Sample (NIS) database was reviewed between 1993 and 2010, identifying LOS and TIC for TAA. Using a multivariate analysis, patient comorbidities, demographics, payment, and hospital details were evaluated. Median LOS decreased from 5 to 2 days, whereas median TICs increased from $21 382.53 to $62 028.00. Regionally, the South and Midwest had decreased TICs, whereas the West had an increased TIC. There was no significant difference in LOS geographically. Rural hospitals demonstrated decreased TICs, whereas urban private hospitals showed decreased LOS and decreased TICs. Large hospitals were associated with increased LOS and TICs. Compared with Medicare, private insurers demonstrated decreased LOS with equivalent TICs. Diabetics significantly increased mean LOS by 1 day, without a significantly increased TIC. Despite a decreased LOS, hospital charges have increased between 1993 and 2010 in TAA. We found that regional differences and hospital characteristics were associated with differences in LOS and TICs. Identification of these factors provides important information to facilities and surgeons. LEVELS OF EVIDENCE: Level IV: Economic/decision analysis.

Effect of Facility on Operative Costs of Total Ankle Arthroplasties.

Cost containment and bundled payments are becoming increasingly important in health care. The purpose of this study was to investigate if ambulatory surgery centers (ASCs) can deliver lower cost care and to identify sources of those cost savings in total ankle replacement (TAR). A cost identification analysis of primary TAR was performed at a single academic medical center. Multiple costs and time measures were taken from 730 consecutive patients over 5 years at either an inpatient facility or ASC. The relationships between total cost and operative time and multiple variables were examined, using multivariate analysis and regression modeling. The mean operative cost over 4 years was significantly greater at the inpatient facility than at the outpatient facility. Significant cost drivers of this difference were inpatient, physical and occupational therapy, pharmacy, and operating room costs. The most significant predictor of cost was facility type. This study supports the use of ASC facilities to achieve efficient resource use in the operative treatment of~total ankle arthroplasties (Journal of Surgical Orthopaedic Advances 27(4):321-324, 2018).

Experience with Navigation in Total Ankle Arthroplasty. Is It Worth the Cost?

Optimal placement of correctly sized total ankle replacement (TAR) implants is elemental to prolonging the working life. The negative mechanical effects of implant malalignment are well characterized. There is one FDA-approved navigated TAR system with limited but encouraging outcomes data. Therefore, its value can be estimated only based on benefits other than a proven clinical outcomes improvement over conventional systems. These include unique preoperative planning through 3-dimensional templating and virtual surgery and the patient-specific cut guides, which also reduce overall instrumentation needed for the case. To better inform this conversation, well-observed longitudinal outcomes studies are warranted.

A Comparison of Relative Value Units in Primary versus Revision Total Ankle Arthroplasty.

INTRODUCTION: To determine the effort required to provide a service, the United States Medicare uses Relative Value Units (RVUs). Consequently, higher RVUs are assigned to the procedures or services that require more effort, which ultimately means the physician will be properly compensated for the additional effort required. In total ankle arthroplasty (TAA), revision cases usually are more technically challenging and require more effort than primary TAA. Therefore, the purpose of this study was to compare the: 1) RVUs; 2) length-of-surgery; 3) RVU per unit of time between primary and revision total ankle arthroplasty; and 4) the individualized idealized surgeon annual cost difference analysis. MATERIALS AND METHODS: We utilized the American College of Surgeons, National Surgical Quality Improvement Program database from 2008 to 2015 to identify patients who underwent either a primary Current Procedural Terminology [CPT]: 27702) or revision (CPT: 27703) TAA. There were a total of 653 patients, 586 of which underwent a primary, and 67 who underwent a revision, TAA. The mean RVUs, length of surgery (in minutes), and RVU per minute, were calculated. Dollar amount per minute, per case, per day, and per year, to find an individualized idealized surgeon annual cost difference, were also calculated. An analysis of variance was used to compare variables between primary and revision TAA. A p-value of less than 0.05 was used to determine statistical significance. RESULTS: The mean RVU was significantly higher in revision versus primary TAA (16.93 vs. 14.41, p=0.001). However, there was no significant difference in the mean lengths of surgery between primary and revision TAA (160 vs. 157 minutes, p=0.613). Additionally, the mean RVU per minute was significantly higher in revision versus primary TAA (0.13 vs. 0.10, p=0.001). CONCLUSION: Based on the results of this study, it appears that revision TAA cases are appropriately assigned a higher RVU per minute for performing them as they require more effort and are more challenging compared to the primary TAA. Furthermore, not only did the revision cases have lower mean lengths of surgery, but they also maintained a higher RVU per minute. Therefore, orthopaedists can use this information to further help them yield the best potential practice design.

Determining the Cost-Savings Threshold and Alignment Accuracy of Patient-Specific Instrumentation in Total Ankle Replacements.

BACKGROUND: Traditional intraoperative referencing for total ankle replacements (TARs) involves multiple steps and fluoroscopic guidance to determine mechanical alignment. Recent adoption of patient-specific instrumentation (PSI) allows for referencing to be determined preoperatively, resulting in less steps and potentially decreased operative time. We hypothesized that usage of PSI would result in decreased operating room time that would offset the additional cost of PSI compared with standard referencing (SR). In addition, we aimed to compare postoperative radiographic alignment between PSI and SR. METHODS: Between August 2014 and September 2015, 87 patients undergoing TAR were enrolled in a prospectively collected TAR database. Patients were divided into cohorts based on PSI vs SR, and operative times were reviewed. Radiographic alignment parameters were retrospectively measured at 6 weeks postoperatively. Time-driven activity-based costing (TDABC) was used to derive direct costs. Cost vs operative time-savings were examined via 2-way sensitivity analysis to determine cost-saving thresholds for PSI applicable to a range of institution types. Cost-saving thresholds defined the price of PSI below which PSI would be cost-saving. A total of 35 PSI and 52 SR cases were evaluated with no significant differences identified in patient characteristics. RESULTS: Operative time from incision to completion of casting in cases without adjunct procedures was 127 minutes with PSI and 161 minutes with SR ( P < .05). PSI demonstrated similar postoperative accuracy to SR in coronal tibial-plafond alignment (1.1 vs 0.3 degrees varus, P = .06), tibial-plafond alignment (0.3 ± 2.1 vs 1.1 ± 2.1 degrees varus, P = .06), and tibial component sagittal alignment (0.7 vs 0.9 degrees plantarflexion, P = .14). The TDABC method estimated a PSI cost-savings threshold range at our institution of $863 below which PSI pricing would provide net cost-savings. Two-way sensitivity analysis generated a globally applicable cost-savings threshold model based on institution-specific costs and surgeon-specific time-savings. CONCLUSIONS: This study demonstrated equivalent postoperative TAR alignment with PSI and SR referencing systems but with a significant decrease in operative time with PSI. Based on TDABC and associated sensitivity analysis, a cost-savings threshold of $863 was identified for PSI pricing at our institution below which PSI was less costly than SR. Similar internal cost accounting may benefit health care systems for identifying cost drivers and obtaining leverage during price negotiations. LEVEL OF EVIDENCE: Level III, therapeutic study.

Influence of Surgeon Volume on Inpatient Complications, Cost, and Length of Stay Following Total Ankle Arthroplasty.

BACKGROUND: Increased surgeon volume may be associated with improved outcomes following operative procedures. However, there is a lack of information on the effect of surgeon volume on inpatient adverse events and resource utilization following total ankle arthroplasty (TAA). METHODS: A retrospective cohort study of TAA patients was performed using the Nationwide Inpatient Sample (NIS) from 2003 to 2009. High-volume surgeons were considered as those with volume ≥90th percentile of surgeons performing TAA. Multivariate regression was used to compare the rates of adverse events, hospital length of stay, and total hospital charges between surgeon volume categories. RESULTS: A total of 4800 TAA patients were identified. The 90th percentile for surgeon volume was 21 cases per year. Mean length of stay was 2.8 ± 2.3 days and mean hospital charges were $45 963 ± $43 983. On multivariate analysis, high-volume surgeons had decreased overall complications (OR 0.5, P = .034) and rate of medial malleolus fracture (OR 0.1, P = .043), decreased length of stay (-0.9 days, P < .001), and decreased hospital charges (-$20 904, P < .001). CONCLUSIONS: Surgeons with volume ≥90th percentile had a decreased rate of complications, decreased length of stay, and reduced hospital charges compared to other surgeons. LEVEL OF EVIDENCE: Level III, comparative study.

In-Patient Trends and Complications After Total Ankle Arthroplasty in the United States.

The number of total ankle arthroplasties (TAAs) performed annually in the United States has increased. The purpose of this study was to evaluate the in-patient demographics, complications, and readmission rates of patients after TAA at academic medical centers in the United States. The University HealthSystems Consortium administrative database was searched for patients who underwent TAA in 2007 to 2011. A descriptive analysis of demographics was performed, followed by a similar analysis of clinical benchmarks, including hospital length of stay, hospital direct cost, in-hospital mortality, and 30-day readmission rates. The study included 2340 adult patients with a mean age of 62 years (47% men and 53% women) who underwent TAA. The majority of patients were Caucasian (2073; 88.5%). Average hospital length of stay was 2.2±1.26 days. Average total direct cost for the hospital was $16,212±7000 per case, with 49.7% of patients having private insurance. In-hospital mortality was less than 1%, and overall complications were 1.4%. Complications after discharge included deep venous thrombosis (2.3%), reoperation (0.7%), and infection (3.2%). A readmission rate of 2.7% within the first 30 days from the time of discharge occurred. Total ankle arthroplasty in the United States is a relatively safe procedure with low overall complication rates. Patients who are male, have a history of community-acquired pneumonia, and have a larger number of preoperative comorbidities had a significant increased risk of developing 1 complication within 30 days of surgery.

Costs Versus Benefits of Routine Histopathological Examination in Total Ankle Replacement.

BACKGROUND: Routine histopathological examination has previously been scrutinized as a source of extraneous cost in orthopedic foot and ankle care. As an increasingly prevalent joint replacement operation, total ankle replacement poses a notable cost to the health care market in an era of cost containment. The purpose of this study was to compare the costs and benefits of routine histopathological examination of specimens removed during total ankle replacement. We hypothesized that a new diagnosis would rarely be found and such examination would seldom alter patient care. METHODS: A retrospective review was conducted of all total ankle replacement operations between 2006 and July 2014 at the investigators' institution. Medical records for 90 patients, undergoing a total of 95 total ankle replacement operations, were reviewed to determine the clinical and pathological diagnoses for each operation and, subsequently, the rates of discrepancy and discordance. Professional charges were determined using estimated reimbursement rates for the Current Procedural Terminology (CPT) codes billed: 88304 (level III microscopic examination), 88305 (level IV microscopic examination), and 88311 (decalcification). RESULTS: Degenerative joint disease was diagnosed by the pathologist in 93.7% of cases (89/95), pseudogout in 4.2% (4/95), and rheumatoid arthritis in 2.1% (2/95). The 4 diagnoses of pseudogout were the only cases of new diagnoses based on pathological review. A total of $16,536.81 was spent for examination of all specimens, for an estimated $4,134.20 spent per discrepant diagnosis. Patient care was unaffected by pathological examination. CONCLUSION: A new diagnosis was rarely found by histopathological examination, and patient care remained unaltered in all cases. The costs of routine histopathological examination of tissue specimens removed during total ankle replacement, therefore, outweigh clinical benefits, and such examination should be left to the discretion of the operating surgeon. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Initial hospital-related cost comparison of total ankle replacement and ankle fusion with hip and knee joint replacement.

BACKGROUND: Total hip and knee arthroplasty (THA and TKA) are accessible to patients with end-stage hip and knee arthritis in most health care systems. The availability of total ankle arthroplasty (TAA) to patients with end-stage ankle arthritis is often restricted because of prosthesis cost. Ankle fusion (AF) is often offered as the only alternative. Patients should have equal access to procedures that are equivalent in total cost. We compared total costs of TAA, AF, THA, and TKA for similar cohorts in a government-funded teaching hospital. METHODS: A subset of 13 TAA and 13 AF patients were selected from the Canadian Orthopaedic Foot and Ankle Society Prospective Ankle Reconstruction Database, and 13 THA and 13 TKA patients were randomly selected from the Canadian Joint Replacement Registry. Total cost was estimated from operating room time, hospital stay, surgeon billing, and equipment used. RESULTS: Mean total cost associated with TAA was $13,500 ± 1000 and was the same as THA ($14,500 ± 1500) and TKA ($12,500 ± 1000). Mean total cost associated with AF was significantly less at $5500 ± 500. Mean operating room time was longer, but mean hospital stay was shorter for the ankle procedures compared with THA and TKA. CONCLUSION: All arthroplasties had similar total costs. Total ankle arthroplasty should not be denied based on prosthetic cost alone, as total procedure cost is equivalent to THA and TKA. We believe ankle fusion is a less expensive and preferable alternative for some patient groups.

Factors associated with longer length of hospital stay after primary elective ankle surgery for end-stage ankle arthritis.

BACKGROUND: Longer length of stay in the hospital after elective surgery results in increased use of health-care resources and higher costs. Improved perioperative care permits many foot and ankle surgical procedures to be performed as day surgery. This study determined perioperative factors associated with a longer length of stay after elective total ankle replacement or ankle arthrodesis. METHODS: Data were prospectively collected on patients who underwent open or arthroscopic ankle fusion or total ankle replacement for end-stage ankle arthritis at our institution from 2003 to 2010. Univariate and multivariable generalized linear regression models with gamma distribution and log link function were conducted with use of the length of the hospital stay as the dependent variable and preselected risk factors of age, sex, physical and mental functional scores, comorbid factors, American Society of Anesthesiologists grade, body mass index, type of surgery, duration of surgery, and surgery day of the week as the independent variables. RESULTS: This study included 343 patients with a median length of stay of seventy-five hours (interquartile range, fifty-two to ninety-seven hours). With use of regression analyses, the variables of age, female sex, higher American Society of Anesthesiologists grade, multiple medical comorbidities, rheumatoid arthritis, lower Short Form-36 Physical Component Summary and General Health domain scores, and open surgery were significantly associated with increased length of stay. Conversely, the variables of obesity, Short Form-36 Mental Component Summary score, surgery day of the week, and surgical duration were not associated with length of stay. Two predictive models of the length of stay were developed: one included only patient-related factors, and the other included patient and surgery-related factors. CONCLUSIONS: The patients who are identified with a higher risk of a longer length of stay may warrant better education and more focused perioperative care when designing care pathways and allocating health-care resources.