The cost-effectiveness of outpatient surgery for primary total hip arthroplasty in the United States: a computer-based cost-utility study

Outpatient vs. inpatient designation in total hip arthroplasty: can we predict who will require hospitalization?

INTRODUCTION

Following removal of total hip arthroplasty (THA) from the inpatient only (IPO) list by the Center for Medicare Services (CMS), arthroplasty surgeons face increased pressure to perform procedures on an outpatient (OP) basis. The purposes of the present study were to compare patients booked for THA as OP who required conversion to IP status postoperatively, to patients who were booked as, and remained OP, and to identify factors predictive of conversion from OP to IP status.

METHODS

We retrospectively reviewed all patients who underwent a primary THA at our institution between January 1, 2020 and April 26, 2022. All patients included were originally scheduled for OP surgery and were separated based on conversion to IP status postoperatively. Multiple regression analyses were used to determine the significance of all perioperative variables. Modeling via binary logistic regressions were used to determine factors predictive of status conversion.

RESULTS

Of 1,937 patients, 372 (19.2%) designated as OP preoperatively required conversion to IP status postoperatively. These patients had significantly higher facility discharge rates (P < 0.001) and 90-day readmission rates (P = 0.024). Patients aged 65 and older (P < 0.001), females (P < 0.001), patients with Black/African American race (P = 0.027), with a recovery room arrival time after 12 pm (P < 0.001), with a BMI > 30 kg/m2 (P = 0.001), and with a Charlson Comorbidity Index (CCI) ≥ 4 (P = 0.013) were Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation more likely to require conversion to IP designation. Marital status and time of procedure were also significant factors, as patients who were married (P < 0.001) and who were the first case of the day (P < 0.001) were less likely to be converted to IP.

CONCLUSION

Several factors were identified which could help determine appropriate hospital designation status at the time of surgical booking to ultimately avoid insurance claim denials. These included BMI, certain demographic factors, CCI ≥ 4, and patients 65 or older.

LEVEL III EVIDENCE

Retrospective Cohort Study.

Local Infiltration Analgesia Is Superior to Regional Nerve Blocks for Total Hip Arthroplasty: Less Falls, Better Mobility, and Same-Day Discharge

Background: Multimodal analgesia in total hip arthroplasty (THA) provides better pain control, mobility, and reduced side effects compared to monotherapies. Local infiltration analgesia (LIA) and regional nerve blocks (RNBs) are commonly used throughout these protocols. This study aimed to compare these procedures as part of a multimodal analgesia protocol for patients undergoing THA. Materials and Methods: A retrospective review of 1100 consecutive elective primary THAs was performed in 996 patients between June 2018 and December 2021. The RNB consisted of a preoperative continuous femoral nerve catheter and single-shot obturator nerve block, and LIA consisted of the intraoperative infiltration of weight-based bupivacaine. Results: A total of 579 (52.6%) patients received RNB, and 521 (47.4%) received LIA. Mean oral morphine equivalents (OMEs) during the first four hours postoperatively were significantly lower for LIA group (p < 0.001). However, the numeric pain rating scale in the post-anesthesia care unit (PACU) was similar between groups. Patients with LIA had significantly greater first ambulation distance in the PACU (p < 0.001), higher successful same-day discharge rate (p = 0.029), fewer falls (p = 0.041), and less refill OMEs post-discharge (p < 0.001) than RNB. Conclusions: In the setting of similar pain management between groups and better functional outcomes for LIA, the use of minimally invasive procedures like LIA for pain control following THA is favorable.

The impact of insurance status on patient placement into inpatient and outpatient orthopaedic surgical centers

BACKGROUND

Innovation has fueled the shift from inpatient to outpatient care for orthopaedic joint arthroplasty. Given this transformation, it becomes imperative to understand what factors help assign care-settings to specific patients for the same procedure. While the comorbidities suffered by patients are important considerations, recent research may point to a more complex determination. Differences in reimbursement structures and patient characteristics across various insurance statuses could potentially influence these decisions.

METHODS

Retrospective binary logistic and ordinary least square (OLS) regression analyses were employed on de-identified inpatient and outpatient orthopaedic arthroplasty data from Albany Medical Center from 2018 to 2022. Data elements included surgical setting (inpatient vs. outpatient), covariates (age, sex, race, obesity, smoking status), Elixhauser comorbidity indices, and insurance status.

RESULTS

Patients insured by Medicare were significantly more likely to be placed in inpatient care-settings for total hip, knee, and ankle arthroplasty when compared to their privately insured counterparts even after Centers for Medicare and Medicaid Services (CMS) removed each individual surgery from its inpatient-only-list (1.65 (p < 0.05), 1.27 (p < 0.05), and 12.93 (p < 0.05) times more likely respectively). When compared to patients insured by the other payers, Medicare patients did not have the most comorbidities (p < 0.05).

CONCLUSIONS

Medicare patients were more likely to be placed in inpatient care-settings for hip, knee, and ankle arthroplasty. However, Medicaid patients were shown to have the most comorbidities. It is of value to note Medicare patients billed for outpatient services experience higher coinsurance rates.

LEVEL OF EVIDENCE

III.

Safety Considerations for Outpatient Arthroplasty

Since 2018, the number of total joint arthroplasties (TJAs) performed on an outpatient basis has dramatically increased. Both surgeon and anesthesiologist should be aware of the implications for the safety of outpatient TJAs and potential patient risk factors that could alter this safety profile. Although smaller studies suggest that the risk of negative outcomes is equivalent when comparing outpatient and inpatient arthroplasty, larger database analyses suggest that, even when matched for comorbidities, patients undergoing outpatient arthroplasty may be at increased risk of surgical or medical complications. Appropriate patient selection is critical for the success of any outpatient arthroplasty program. Potential exclusion criteria for outpatient TJA may include age greater than 75 years, bleeding disorder, history of deep vein thrombosis, uncontrolled diabetes mellitus, and hypoalbuminemia, among others. Patient optimization before surgery is also warranted. The potential risks of same-day versus next-day discharge have yet to be elicited in a large-scale manner.

Prevalence, contributing factors, and interventions to reduce medication errors in outpatient and ambulatory settings: a systematic review

BACKGROUND

Medication errors are common events that compromise patient safety. Outpatient and ambulatory settings enhance access to healthcare which has been linked to favorable outcomes. While medication errors have been extensively researched in inpatient settings, there is dearth of literature from outpatient settings.

AIM

To synthesize the peer-reviewed literature on the prevalence, nature, contributory factors, and interventions to minimize medication errors in outpatient and ambulatory settings.

METHOD

A systematic review was conducted using Medline, Embase, CINAHL, and Google Scholar which were searched from 2011 to November 2021. Quality assessment was conducted using the quality assessment checklist for prevalence studies tool. Data related to contributory factors were synthesized according to Reason's accident causation model.

RESULTS

Twenty-four articles were included in the review. Medication errors were common in outpatient and ambulatory settings (23-92% of prescribed drugs). Prescribing errors were the most common type of errors reported (up to 91% of the prescribed drugs, high variations in the data), with dosing errors being most prevalent (up to 41% of the prescribed drugs). Latent conditions, largely due to inadequate knowledge, were common contributory factors followed by active failures. The seven studies that discussed interventions were of poor quality and none used a randomized design.

CONCLUSION

Medication errors (particularly prescribing errors and dosing errors) in outpatient settings are prevalent, although reported prevalence range is wide. Future research should be informed by behavioral theories and should use high quality designs. These interventions should encompass system-level strategies, multidisciplinary collaborations, effective integration of pharmacists, health information technology, and educational programs.

The successful and safe conversion of joint arthroplasty to same-day surgery: A necessity after the COVID-19 pandemic

INTRODUCTION

A key strategy to address system pressures on hip and knee arthroplasty through the COVID-19 pandemic has been to shift procedures to the outpatient setting.

METHODS

This was a retrospective cohort and case-control study. Using the Discharge Abstract Database and the National Ambulatory Care Reporting System databases, we estimated the use of outpatient hip and knee arthroplasty in Ontario, Canada. After propensity-score matching, we estimated rates of 90-day readmission, 90-day emergency department (ED) visit, 1-year mortality, and 1-year infection or revision.

RESULTS

204,066 elective hip and 341,678 elective knee arthroplasties were performed from 2010-2022. Annual volumes of hip and knee arthroplasties increased steadily until 2020. Following the start of the COVID-19 pandemic (March 1, 2020) through December 31, 2022 there were 7,561 (95% CI 5,435 to 9,688) fewer hip and 20,777 (95% CI 17,382 to 24,172) fewer knee replacements performed than expected. Outpatient arthroplasties increased as a share of all surgeries from 1% pre-pandemic to 39% (hip) and 36% (knee) by 2022. Among inpatient arthroplasties, the tendency to discharge to home did not change since the start of the pandemic. During the COVID-19 era, patients receiving arthroplasty in the outpatient setting had a similar or lower risk of readmission than matched patients receiving inpatient arthroplasty [hip: RR 0.65 (0.56-0.76); knee: RR 0.86 (0.76-0.97)]; ED visits [hip: RR 0.78 (0.73-0.83); knee: RR 0.92 (0.88-0.96)]; and mortality, infection, or revision [hip: RR 0.65 (0.45-0.93); knee: 0.90 (0.64-1.26)].

CONCLUSION

Following the start of the COVID-19 pandemic in Ontario, the volume of outpatient hip and knee arthroplasties performed increased despite a reduction in overall arthroplasty volumes. This shift in surgical volumes from the inpatient to outpatient setting coincided with pressures on hospitals to retain inpatient bed capacity. Patients receiving arthroplasty in the outpatient setting had relatively similar outcomes to those receiving inpatient surgery after matching on known sociodemographic and clinical characteristics.

Development and benchmarking of machine learning models to classify patients suitable for outpatient lower extremity joint arthroplasty

STUDY OBJECTIVE

Performing hip or knee arthroplasty as an outpatient surgery has been shown to be operationally and financially beneficial for selected patients. By applying machine learning models to predict patients suitable for outpatient arthroplasty, health care systems can better utilize resources efficiently. The goal of this study was to develop predictive models for identifying patients likely to be discharged same-day following hip or knee arthroplasty.

DESIGN

Model performance was assessed with 10-fold stratified cross-validation, evaluated over baseline determined by the proportion of eligible outpatient arthroplasty over sample size. The models used for classification were logistic regression, support vector classifier, balanced random forest, balanced bagging XGBoost classifier, and balanced bagging LightGBM classifier.

SETTING

The patient records were sampled from arthroplasty procedures at a single institution from October 2013 to November 2021.

PATIENTS

The electronic intake records of 7322 knee and hip arthroplasty patients were sampled for the dataset. After data processing, 5523 records were kept for model training and validation.

INTERVENTIONS

None.

MEASUREMENTS

The primary measures for the models were the F1-score, area under the receiver operating characteristic curve (ROCAUC), and area under the precision-recall curve. To measure feature importance, the SHapley Additive exPlanations value (SHAP) were reported from the model with the highest F1-score.

RESULTS

The best performing classifier (balanced random forest classifier) achieved an F1-score of 0.347: an improvement of 0.174 over baseline and 0.031 over logistic regression. The ROCAUC for this model was 0.734. Using SHAP, the top determinant features of the model included patient sex, surgical approach, surgery type, and body mass index.

CONCLUSIONS

Machine learning models may utilize electronic health records to screen arthroplasty procedures for outpatient eligibility. Tree-based models demonstrated superior performance in this study.

Early Total Hip Arthroplasty is a Cost-Effective Treatment for Severe Radiographic Slipped Capital Femoral Epiphysis Over an Individual's Lifetime

BACKGROUND

Slipped capital femoral epiphysis (SCFE) causes degenerative changes warranting total hip arthroplasty (THA) in approximately 50% of patients by age 60 years. For severe SCFE, a reorienting intertrochanteric osteotomy (ITO) following in situ pinning (ISP) can decrease impingement with hip flexion, but by altering proximal femoral geometry, complicates subsequent conversion THA. We hypothesized that increasing implant survivorship would affect the most cost-effective treatment strategy (ISP followed by ITO [ISP + ITO] with later THA versus ISP alone [ISPa] with earlier THA) over a patient's lifetime.

METHODS

A state-transition Markov model was constructed to analyze the cost-effectiveness of either ISPa or ISP + ITO over a 60-year time horizon for children who have severe, stable SCFE. Transition probabilities associated with implant and native hip survivorship, state utilities, and costs were derived from the literature. Sensitivity analyses assessed the model robustness. Incremental cost-effectiveness ratios (ICERs) were compared to a societal willingness to pay (WTP) of $100,000 per quality-adjusted life year (QALY).

RESULTS

Over a 60-year horizon, ISPa was costlier ($291,836) than ISP + ITO ($75,227) but achieved overall better outcomes (51.4 QALYs ISPa versus 48.7 QALYs ISP + ITO), rendering ISPa cost-effective with an ICER of $80,980/QALY. Implant survivorship and time horizon were sensitive variables.

CONCLUSION

Based upon current implant performance, ISPa with subsequent earlier THA is cost-effective when considering an individual's life expectancy and thereby deserves consideration in patients who have severe SCFE. Without clear level 1 clinical data, our economic model considers a difficult problem, while providing families and clinicians with a framework for understanding treatment options.

LEVEL OF EVIDENCE

Economic and decision analysis, Level III.

Cost-effectiveness of Same-day Discharge Surgery for Primary Total Hip Arthroplasty: A Pragmatic Randomized Controlled Study

Background

Total hip arthroplasty (THA) causes a great medical burden globally, and the same-day discharge (SDD) method has previously been considered to be cost saving. However, a standard cost-effectiveness analysis (CEA) in a randomized controlled trial (RCT) is needed to evaluated the benefits of SDD when performing THA from the perspective of both economic and clinical outcomes.

Methods

Eighty-four participants undergoing primary THA were randomized to either the SDD group or the inpatient group. Outcomes were assessed by an independent orthopedist who was not in the surgical team, using the Oxford Hip Score (OHS), EuroQol 5D (EQ-5D), SF-36 scores and the quality-adjusted life years (QALYs). All the cost information was also collected.

Results

The mean stay of patients in the SDD group was 21.70 ± 3.45 h, while the inpatient group was 78.15 ± 26.36 h. This trial did not detect any significant differences in OHS and QALYs. The total cost in the SDD group was significantly lower than that in the inpatient group (¥69,771.27 ± 6,608.00 vs. ¥80,666.17 ± 8,421.96, p < 0.001). From the perspective of total cost, when measuring OHS, the incremental effect was -0.12 and the incremental cost was -¥10,894.90. The mean incremental cost-effectiveness ratio (ICER) was 90,790.83. When measuring QALYs, the incremental effect was 0.02, and the ICER was negative. Sensitivity analysis produced similar results.

Conclusions

SDD has an acceptable likelihood of being more cost-effective than the traditional inpatient option. After conducting cost-utility analysis, SDD resulted in better QALYs, while significantly reducing the total cost.

Safety Considerations for Outpatient Arthroplasty

Since 2018, the number of total joint arthroplasties (TJAs) performed on an outpatient basis has dramatically increased. Both surgeon and anesthesiologist should be aware of the implications for the safety of outpatient TJAs and potential patient risk factors that could alter this safety profile. Although smaller studies suggest that the risk of negative outcomes is equivalent when comparing outpatient and inpatient arthroplasty, larger database analyses suggest that, even when matched for comorbidities, patients undergoing outpatient arthroplasty may be at increased risk of surgical or medical complications. Appropriate patient selection is critical for the success of any outpatient arthroplasty program. Potential exclusion criteria for outpatient TJA may include age greater than 75 years, bleeding disorder, history of deep vein thrombosis, uncontrolled diabetes mellitus, and hypoalbuminemia, among others. Patient optimization before surgery is also warranted. The potential risks of same-day versus next-day discharge have yet to be elicited in a large-scale manner.

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.

Cost effectiveness of outpatient lumbar discectomy

Background

Microdiscectomy is the most commonly performed spine surgery and the first transitioning for outpatient settings. However, this transition was never studied, in what comes to cost-utility assessment. Accordingly, this economic study aims to access the cost-effectiveness of outpatient lumbar microdiscectomy when compared with the inpatient procedure.

Methods

This is a cost utility study, adopting the hospital perspective. Direct medical costs were retrieved from the assessment of 20 patients undergoing outpatient lumbar microdiscectomy and 20 undergoing inpatient lumbar microdiscectomy Quality-adjusted life-years were calculated from Oswestry Disability Index values (ODI). ODI was prospectively assessed in outpatients in pre and 3- and 6-month post-operative evaluations. Inpatient ODI data were estimated from a meta-analysis. A probabilistic sensitivity analysis was performed and incremental cost-effectiveness ratio (ICER) calculated.

Results

Outpatient procedure was cost-saving in all models tested. At 3-month assessment ICER ranged from €135,753 to €345,755/QALY, higher than the predefined threshold of €60,000/QALY gained. At 6-month costs were lower and utilities were higher in outpatient, overpowering the inpatient procedure. Probabilistic sensitivity analysis showed that in 65% to 73% of simulations outpatient was the better option. The savings with outpatient were about 55% of inpatient values, with similar utility scores. No 30-day readmissions were recorded in either group.

Conclusion

This is the first economic study on cost-effectiveness of outpatient lumbar microdiscectomy, showing a significant reduction in costs, with a similar clinical outcome, proving it cost-effective.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12962-021-00272-w.

Day-case total hip arthroplasty: a literature review and development of a hospital pathway

Aims

We present the development of a day-case total hip arthroplasty (THA) pathway in a UK National Health Service institution in conjunction with an extensive evidence-based summary of the interventions used to achieve successful day-case THA to which the protocol is founded upon.

Methods

We performed a prospective audit of day-case THA in our institution as we reinitiate our full capacity elective services. In parallel, we performed a review of the literature reporting complication or readmission rates at ≥ 30-day postoperative following day-case THA. Electronic searches were performed using four databases from the date of inception to November 2020. Relevant studies were identified, data extracted, and qualitative synthesis performed.

Results

Our evaluation and critique of the evidence-based literature identifies day-case THA to be safe, effective, and economical, benefiting both patients and healthcare systems alike. We further validate this with our institutional elective day surgery arthroplasty pathway (EDSAP) and report a small cohort of successful day-case THA cases as an example in the early stages of this practice in our unit.

Conclusion

Careful patient selection and education, adequate perioperative considerations, including multimodal analgesia, surgical technique and blood loss management protocols and appropriate postoperative pathways comprising reliable discharge criteria are essential for successful day-case THA.

Cite this article: Bone Jt Open 2021;2(2):93–102.