Clinical Decision Analysis and Markov Modeling for Surgeons: An Introductory Overview

The health economics of orthopaedic foot and ankle surgery

The cost of healthcare spending in foot and ankle surgery continues to rise. Several recent studies about cost effectiveness have been published. These may be difficult to understand and analyze without a background in business and healthcare economics. The goal of this narrative review is to provide the fundamentals for understanding and interpreting healthcare economic studies by defining key terminology and providing examples in the field of foot and ankle surgery. Foot and ankle surgeons should be familiar with the elements that comprise cost-effectiveness for providers, clinicians, researchers, and economists in caring for patients and making healthcare-related decisions.

Introducing Attribute Association Graphs to Facilitate Medical Data Exploration: Development and Evaluation Using Epidemiological Study Data

BACKGROUND

Interpretability and intuitive visualization facilitate medical knowledge generation through big data. In addition, robustness to high-dimensional and missing data is a requirement for statistical approaches in the medical domain. A method tailored to the needs of physicians must meet all the abovementioned criteria.

OBJECTIVE

This study aims to develop an accessible tool for visual data exploration without the need for programming knowledge, adjusting complex parameterizations, or handling missing data. We sought to use statistical analysis using the setting of disease and control cohorts familiar to clinical researchers. We aimed to guide the user by identifying and highlighting data patterns associated with disease and reveal relations between attributes within the data set.

METHODS

We introduce the attribute association graph, a novel graph structure designed for visual data exploration using robust statistical metrics. The nodes capture frequencies of participant attributes in disease and control cohorts as well as deviations between groups. The edges represent conditional relations between attributes. The graph is visualized using the Neo4j (Neo4j, Inc) data platform and can be interactively explored without the need for technical knowledge. Nodes with high deviations between cohorts and edges of noticeable conditional relationship are highlighted to guide the user during the exploration. The graph is accompanied by a dashboard visualizing variable distributions. For evaluation, we applied the graph and dashboard to the Hamburg City Health Study data set, a large cohort study conducted in the city of Hamburg, Germany. All data structures can be accessed freely by researchers, physicians, and patients. In addition, we developed a user test conducted with physicians incorporating the System Usability Scale, individual questions, and user tasks.

RESULTS

We evaluated the attribute association graph and dashboard through an exemplary data analysis of participants with a general cardiovascular disease in the Hamburg City Health Study data set. All results extracted from the graph structure and dashboard are in accordance with findings from the literature, except for unusually low cholesterol levels in participants with cardiovascular disease, which could be induced by medication. In addition, 95% CIs of Pearson correlation coefficients were calculated for all associations identified during the data analysis, confirming the results. In addition, a user test with 10 physicians assessing the usability of the proposed methods was conducted. A System Usability Scale score of 70.5% and average successful task completion of 81.4% were reported.

CONCLUSIONS

The proposed attribute association graph and dashboard enable intuitive visual data exploration. They are robust to high-dimensional as well as missing data and require no parameterization. The usability for clinicians was confirmed via a user test, and the validity of the statistical results was confirmed by associations known from literature and standard statistical inference.

Sleeve Gastrectomy Reduces the Need for Liver Transplantation in Patients with Obesity and Non-Alcoholic Steatohepatitis: a Predictive Model

BACKGROUND

Non-alcoholic steatohepatitis (NASH) is one of the leading indications for liver transplantation (LT) in the United States. As with the current obesity epidemic, the incidence of NASH continues to rise. However, the impact of broad utilization of bariatric surgery (BS) for patients with NASH is unknown, particularly in regard to mitigating the need for LT.

METHODS

Markov decision analysis was performed to simulate the lives of 20,000 patients with obesity and concomitant NASH who were deemed ineligible to be waitlisted for LT unless they achieved a body mass index (BMI) < 35 kg/m2. Life expectancy following medical weight management (MWM) and sleeve gastrectomy (SG) were estimated. Base case patients were defined as having NASH without fibrosis and a pre-intervention BMI of 45 kg/m2. Sensitivity analysis of initial BMI was performed.

RESULTS

Simulated base case analysis patients who underwent SG gained 14.3 years of life compared to patients who underwent MWM. One year after weight loss intervention, 9% of simulated MWM patients required LT compared to only 5% of SG patients. Survival benefit for SG was observed above a BMI of 32.2 kg/m2.

CONCLUSION

In this predictive model of 20,000 patients with obesity and concomitant NASH, surgical weight loss is associated with a reduction in the progression of NASH, thereby reducing the need for LT. A reduced BMI threshold of 32 kg/m2 for BS may offer survival benefit for patients with obesity and NASH.

Decision analysis in cardiac surgery: a scoping review and methodological primer

OBJECTIVES

Randomized controlled trials are the gold standard for evidence generation in medicine but are limited by their real-world generalizability, resource needs, shorter follow-up durations and inability to be conducted for all clinical questions. Decision analysis (DA) models may simulate trials and observational studies by using existing data and evidence- and expert-informed assumptions and extend analyses over longer time horizons, different study populations and specific scenarios, helping to translate population outcomes to patient-specific clinical and economic outcomes. Here, we present a scoping review and methodological primer on DA for cardiac surgery research.

METHODS

A scoping review was performed using the PubMed/MEDLINE, EMBASE and Web of Science databases for cardiac surgery DA studies published until December 2021. Articles were summarized descriptively to quantify trends and ascertain methodological consistency.

RESULTS

A total of 184 articles were identified, among which Markov models (N = 92, 50.0%) were the most commonly used models. The most common outcomes were costs (N = 107, 58.2%), quality-adjusted life-years (N = 96, 52.2%) and incremental cost-effectiveness ratios (N = 89, 48.4%). Most (N = 165, 89.7%) articles applied sensitivity analyses, most frequently in the form of deterministic sensitivity analyses (N = 128, 69.6%). Reporting of guidelines to inform the model development and/or reporting was present in 22.3% of articles.

CONCLUSION

DA methods are increasing but remain limited and highly variable in cardiac surgery. A methodological primer is presented and may provide researchers with the foundation to start with or improve DA, as well as provide readers and reviewers with the fundamental concepts to review DA studies.

Ventricular Remodeling Following Metabolic and Bariatric Surgery Decreases Need for Heart Transplantation: A Predictive Model

PURPOSE

For patients with obesity and congestive heart failure (CHF) who require heart transplantation (HT), aggressive weight loss has been associated with ventricular remodeling, or subclinical alterations in left and right ventricular structure that affect systolic function. Many have suggested offering metabolic and bariatric surgery (MBS) for these patients. As such, we evaluated the role of MBS in HT for patients with obesity and CHF using predictive modelling techniques.

MATERIALS AND METHODS

Markov decision analysis was performed to simulate the life expectancy of 30,000 patients with concomitant obesity, CHF, and 30% ejection fraction (EF) who were deemed ineligible to be waitlisted for HT unless they achieved a BMI < 35 kg/m2. Life expectancy following diet and exercise (DE), Roux-en-Y gastric bypass (RYGB), and sleeve gastrectomy (SG) was estimated. Base case patients were defined as having a pre-intervention BMI of 45 kg/m2. Sensitivity analysis of initial BMI was performed.

RESULTS

RYGB patients had lower rates of HT and received HT quicker when needed. Base case patients who underwent RYGB gained 2.2 additional mean years survival compared with patients who underwent SG and 10.3 additional mean years survival compared with DE. SG patients gained 6.2 mean years of life compared with DE.

CONCLUSION

In this simulation of 30,000 patients with obesity, CHF, and reduced EF, MBS was associated with improved survival by not only decreasing the need for transplantation due to improvements in EF, but also increasing access to HT when needed due to lower average BMI.

Case studies of clinical decision-making through prescriptive models based on machine learning

BACKGROUND

The development of computational methodologies to support clinical decision-making is of vital importance to reduce morbidity and mortality rates. Specifically, prescriptive analytic is a promising area to support decision-making in the monitoring, treatment and prevention of diseases. These aspects remain a challenge for medical professionals and health authorities.

MATERIALS AND METHODS

In this study, we propose a methodology for the development of prescriptive models to support decision-making in clinical settings. The prescriptive model requires a predictive model to build the prescriptions. The predictive model is developed using fuzzy cognitive maps and the particle swarm optimization algorithm, while the prescriptive model is developed with an extension of fuzzy cognitive maps that combines them with genetic algorithms. We evaluated the proposed approach in three case studies related to monitoring (warfarin dose estimation), treatment (severe dengue) and prevention (geohelminthiasis) of diseases.

RESULTS

The performance of the developed prescriptive models demonstrated the ability to estimate warfarin doses in coagulated patients, prescribe treatment for severe dengue and generate actions aimed at the prevention of geohelminthiasis. Additionally, the predictive models can predict coagulation indices, severe dengue mortality and soil-transmitted helminth infections.

CONCLUSIONS

The developed models performed well to prescribe actions aimed to monitor, treat and prevent diseases. This type of strategy allows supporting decision-making in clinical settings. However, validations in health institutions are required for their implementation.

Understanding Health Economics in Hand Surgery

Rising health care costs in the United States, besides evolving payment models that place emphasis on value instead of volume, have led to an increasing number of studies evaluating hand surgery from an economic perspective. To better understand such economics-based studies, this review provides a foundational understanding of what value entails by defining its features of quality and cost. Principles of evaluating value through cost-benefit, cost-effectiveness, and cost-utility analyses are discussed. Models of discounting and clinical decision analyses are also discussed. Understanding such concepts and their evaluation in economic analyses will provide greater insight into the economic landscape of hand surgery and improving patient care.

Despite Increasing Costs, Perfusion Machines Expand the Donor Pool of Livers and Could Save Lives

INTRODUCTION

Liver transplantation is a highly successful treatment for liver failure and disease. However, demand continues to outstrip our ability to provide transplantation as a treatment. Many livers initially considered for transplantation are not used because of concerns about their viability or logistical issues. Recent clinical trials have shown discarded livers may be viable if they undergo machine perfusion, which allows a more objective assessment of liver quality.

METHODS

Using the Scientific Registry of Transplant Recipients dataset, we examined discarded and unretrieved organs to determine their eligibility for perfusion. We then used a Markov decision-analytic model to perform a cost-effectiveness analysis of two competing transplant strategies: Static Cold Storage (SCS) alone versus Static Cold Storage and Normothermic Machine Perfusion (NMP) of discarded organs.

RESULTS

The average predicted successful transplants after perfusion was 385, representing a 5.8% increase in the annual yield of liver transplants. Our cost-effectiveness analysis found that the SCS strategy generated 4.64 quality-adjusted life years (QALYs) and cost $479,226. The combined SCS + NMP strategy generated 4.72 QALYs and cost $481,885. The combined SCS + NMP strategy had an incremental cost-effectiveness ratio of $33,575 per additional QALY over the 10-year study horizon.

CONCLUSIONS

Machine perfusion of livers currently not considered viable for transplant could increase the number of transplantable grafts by approximately 5% per year and is cost-effective compared to Static Cold Storage alone.

Incorporating economic analysis in interventional cardiology research

Evaluative research in interventional cardiology has focused on clinical and technical outcomes. Inclusion of economic data can enhance evaluative research by quantifying the relative economic burden incurred by different therapies. When combined with clinical outcomes, cost data can provide a measure of value (e.g., marginal cost-effectiveness). In some select situations, cost data can also be used as surrogates for complexity of care and morbidity. In this narrative review, we aim to provide a framework for the application of cost data in clinical trials and observational research, detailing how to incorporate this kind of data into interventional cardiology research.

An ex-ante cost-utility analysis of the deemed consent legislation compared to expressed consent for kidney transplantations in Nova Scotia

Background

This study was an ex-ante cost-utility analysis of deemed consent legislation for deceased organ donation in Nova Scotia, a province in Canada. The legislation became effective in January 2021. The study's objective was to assess the conditions necessary for the legislation change’s cost-effectiveness compared to expressed consent, focusing on kidney transplantation (KT).

Method

We performed a cost-utility analysis using a Markov model with a lifetime horizon. The study was from a Canadian payer perspective. The target population was patients with end-stage kidney disease (ESKD) in Atlantic Canada waitlisted for KT. The intervention was the deemed consent and accompanying health system transformations. Expressed consent (before the change) was the comparator. We simulated the minimum required increase in deceased donor KT per year for the cost-effectiveness of the deemed consent. We also evaluated how changes in dialysis and maintenance immunosuppressant drug costs and living donor KT per year impacted cost-effectiveness in sensitivity analyses.

Results

The expected lifetime cost of an ESKD patient ranged from $177,663 to $553,897. In the deemed consent environment, the expected lifetime cost per patient depended on the percentage increases in the proportion of ESKD patients on the waitlist getting a KT in a year. The incremental cost-utility ratio (ICUR) increased with deceased donor KT per year. Cost-effectiveness of deemed consent compared to expressed consent required a minimum of a 1% increase in deceased donor KT per year. A 1% increase was associated with an ICUR of $32,629 per QALY (95% CI: − $64,279, $232,488) with a 81% probability of being cost-effective if the willingness-to-pay (WTP) was $61,466. Increases in dialysis and post-KT maintenance immunosuppressant drug costs above a threshold impacted value for money. The threshold for immunosuppressant drug costs also depended on the percent increases in deceased donor KT probability and the WTP threshold.

Conclusions

The deemed consent legislation in NS for deceased organ donation and the accompanying health system transformations are cost-effective to the extent that they are anticipated to contribute to more deceased donor KTs than before, and even a small increase in the proportion of waitlist patients receiving a deceased donor KT than before the change represents value for money.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12962-022-00390-z.

Effect of Integrative Chinese and Western Medicine Therapy on Long-Term Clinical Outcomes in Patients with Heart Failure: A Real-World Study Including 394 Patients

Objective. To explore the effect of integrative Chinese and Western medicine therapy on the clinical outcomes of patients with heart failure. Methods. This is a retrospective cohort study in the real world. Patients were divided into “conventional therapy” and “integrative therapy” groups according to treatment modality. The occurrence of cardiovascular events (CVE) was determined during follow-up. Survival curves were plotted, and survival analysis was performed using Cox regression to report survival in both groups. Further subgroup tests were performed as sensitivity analyses. A Markov model was constructed to predict patients with distant heart failure conditions based on real follow-up data. Results. Based on diagnostic criteria, 394 patients with heart failure were included. The integrative therapy group had (N = 181) older patients ( $P=0.005$ ), higher proportion of renal insufficiency ( $P<0.001$ ), higher creatinine ( $P=0.040$ ), hypersensitive C-reactive protein ( $P=0.007$ ), N-terminal pro-B type natriuretic peptide ( $P=0.019$ ) levels, more patients in cardiac function class IV ( $P=0.004$ ), and longer hospital days ( $P=0.003$ ) than the conventional therapy group (N = 213). Survival was better in the integrative therapy group than in the conventional therapy group (log-rank $P<0.001$ ). Multifactorial Cox regression identified “conventional therapy” or “integrative therapy” as an independent factor affecting the risk of CVE in patients with heart failure, with the risk of CVE being lower in the integrative therapy group (HR = 0.322, 95% CI = 0.185–0.561). A subgroup analysis found no significant association between therapy modality and risk of CVE in older patients (age ≥65 years, $P=0.210$ ) and those who had renal insufficiency ( $P=0.062$ ). The Markov model predicted better cardiac function in the integrative therapy group than in the conventional therapy group at all time points (all $P<0.001$ ). Conclusion. In patients with heart failure, integrative therapy of Chinese and Western medicine had better long-term outcomes than conventional therapy. However, patients with advanced age and renal insufficiency had no significant advantage. Trials Registration. This trial is registered with China Clinical Trials Registry, ChiCTR2100050927, registered 8 September 2021, https://www.chictr.org.cn/showproj.aspx?proj=133451.

Cost-effectiveness of using protons for breast irradiation aiming at minimizing cardiotoxicity: A risk-stratification analysis

Background

Incidental exposure of the heart to ionizing irradiation is associated with an increased risk of ischemic heart disease and subsequent fatality in patients with breast cancer after radiotherapy. Proton beam therapy can limit the heart dose in breast irradiation to a negligible level. However, compared with conventional photon modality, proton breast irradiation is more expensive. In this study, we performed cost-effectiveness analyses to identify the type of patients who would be more suitable for protons.

Methods

A Markov decision model was designed to evaluate the cost-effectiveness of protons vs. photons in reducing the risk of irradiation-related ischemic heart disease. A baseline evaluation was performed on a 50-year-old woman patient without the preexisting cardiac risk factor. Furthermore, risk-stratification analyses for photon mean heart dose and preexisting cardiac risk were conducted on 40-, 50-, and 60-year-old women patients under different proton cost and willingness-to-pay (WTP) settings.

Results

Using the baseline settings, the incremental effectiveness (protons vs. photons) increased from 0.043 quality-adjusted life-year (QALY) to 0.964 QALY when preexisting cardiac risk increased to 10 times its baseline level. At a proton cost of 50,000 US dollars ($), protons could be cost-effective for ≤ 60-year-old patients with diabetes and ≤50-year-old patients with grade II–III hypertension at the WTP of China ($37,653/QALY); for ≤ 60-year-old patients with diabetes and ≤ 50-year-old patients with grade II–III hypertension or ≥ 2 major cardiac risk factors at a WTP of $50,000/QALY; and for ≤ 60-year-old patients with diabetes, grade II–III hypertension or ≥ 2 major cardiac risk factors and ≤ 50-year-old patients with total cholesterol ≥ 240 mg/dL at a WTP of $100,000/QALY.

Conclusion

Patients' preexisting cardiac risk status was a key factor affecting the cardiac benefits gained from protons and should therefore be a major consideration for the clinical decision of using protons; cost-effective scenarios of protons exist in those patients with high risk of developing cardiac diseases.

Understanding Health Economics in Joint Replacement Surgery

The number of arthroplasty procedures has been rising at a significant rate, contributing to a notable portion of the nation's health care spending. This growth has contributed to an increase in the number of health care economic studies in the field of adult reconstruction surgery. Although these articles are filled with important information, they can be difficult to understand without a background in business or economics. The goal of this review is to define the common terminology used in health care economic studies, assess their value and benefit in the context of total joint arthroplasty, and highlight shortcomings in the current literature. [Orthopedics. 2022;45(4):e174-e182.].

Cost-Effectiveness Analysis of Negative Pressure Wound Therapy to Prevent Surgical Site Infection After Elective Colorectal Surgery

BACKGROUND

Surgical site infection is common after colorectal surgery and is associated with increased costs. Prophylactic negative pressure wound therapy has previously been shown to reduce surgical site infection compared with conventional dressings. However, negative pressure wound therapy application is met with hesitancy because of its additional cost.

OBJECTIVE

This study aims to determine whether the application of prophylactic negative pressure wound therapy after elective colorectal surgery is cost-effective.

DESIGN

A cost-effectiveness analysis comparing prophylactic negative pressure wound therapy versus conventional dressing was completed using a Markov microsimulation model. A publicly funded single health care payer perspective was adopted across a lifetime horizon.

SETTING

This study was conducted using in-hospital elective colorectal surgery.

PATIENTS

The base case was an age-, sex-, and comorbidity-standardized patient undergoing open elective colorectal surgery.

INTERVENTION

Negative pressure wound therapy was applied postoperatively over closed incisions.

MAIN OUTCOMES

The primary outcomes of interest were the number of surgical site infections, total costs, and quality-adjusted life-years gained. Secondary outcomes included emergency department presentation, hospital readmission, nursing wound care utilization, fascial dehiscence, incisional hernia, and non-surgical site infection-related complications.

RESULTS

We found that prophylactic negative pressure wound therapy, standardized to 1000 patients, prevented 51 surgical site infections, 3 fascial dehiscences, 10 incisional hernias, 22 emergency department presentations, and 6 hospital readmissions. This resulted in a total cost saving of $17,066 and 92.2 quality-adjusted life-years gained ($17.07 and 0.09 quality-adjusted life-years gained on average per patient). When the patients' risk of surgical site infections was greater than 3.2%, negative pressure wound therapy was a cost-effective strategy at a willingness to pay of $50,000/quality-adjusted life-years.

LIMITATIONS

We did not model for societal perspective, emergent presentations of incarcerated hernias, or complications with hernia repair. The results of this model are reliant on the published negative pressure wound therapy efficacy and may change when additional data arise.

CONCLUSION

The use of negative pressure wound therapy is the dominant strategy with improved outcomes and reduced costs compared with conventional dressing in patients undergoing colorectal surgery, particularly in at-risk patients. See Video Abstract at http://links.lww.com/DCR/B782.

ANLISIS DE RENTABILIDAD DE LA TERAPIA DE PRESIN NEGATIVA PARA PREVENIR INFECCIN DEL SITIO QUIRRGICO DESPUS DE CIRUGA COLORRECTAL ELECTIVA

ANTECEDENTES:La infección del sitio quirúrgico es común después de la cirugía colorrectal y se asocia con un aumento de los costos. Anteriormente se demostró que la terapia profiláctica con presión negativa reduce la infección del sitio quirúrgico en comparación con los apósitos convencionales. Sin embargo, el uso de la terapia de presión negativa se encuentra en dudas debido a su costo adicional.OBJETIVO:Determinar si la aplicación de la terapia profiláctic con presión negativa después de la cirugía colorrectal electiva es rentable.DISEÑO:Se completó un análisis de costo-efectividad comparando la terapia profiláctica con presión negativa versus apósito convencional utilizando un modelo de microsimulación de Markov. Se adoptó una perspectiva de pagador único de asistencia sanitaria financiada con fondos públicos a lo largo de toda la vida.AJUSTE:Cirugía colorrectal electiva intrahospitalaria.PACIENTES:El caso base fue un paciente estandarizado por edad, sexo y comorbilidad sometido a cirugía colorrectal abierta electiva.INTERVENCIÓN:Aplicación postoperatoria de terapia de presión negativa sobre incisiones cerradas.RESULTADOS PRINCIPALES:Los resultados primarios de interés fueron el número de infecciones del sitio quirúrgico, los costos totales y los años de vida ganados ajustados por calidad. Los resultados secundarios incluyeron presentación en la sala de emergencias, reingreso al hospital, la utilización del cuidado de heridas por enfermería, dehiscencia fascial, hernia incisional y complicaciones relacionadas con infecciones del sitio no quirúrgico.RESULTADOS:Estandarizado para 1,000 pacientes, encontramos que la terapia profiláctica con presión negativa previno 51 infecciones del sitio quirúrgico, 3 dehiscencias fasciales, 10 hernias incisionales, 22 presentaciones en la sala de emergencias y 6 reingresos al hospital. Esto resultó en un ahorro total de costos de $ 17.066 y 92.2 años de vida ganados ajustados por calidad ($ 17.07 y 0.09 años de vida ganados ajustados por calidad en promedio por paciente). Cuando el riesgo de infección del sitio quirúrgico de los pacientes era superior al 3,2%, la terapia de presión negativa era una estrategia rentable con una disposición a pagar de 50.000 dólares por años de vida ajustados por calidad.LIMITACIONES:No modelamos para la perspectiva social, presentaciones emergentes de hernias encarceladas o complicaciones con la reparación de hernias. Los resultados de este modelo dependen de la eficacia publicada de la terapia de presión negativa y pueden cambiar cuando surjan más datos.CONCLUSIONES:El uso de la terapia de presión negativa es la estrategia dominante con mejores resultados y costos reducidos en comparación con el apósito convencional en pacientes sometidos a cirugía colorrectal, particularmente en pacientes de riesgo. Consulte Video Resumen en http://links.lww.com/DCR/B782. (Traducción- Dr. Francisco M. Abarca-Rendon).

Particulated Juvenile Articular Cartilage and Matrix-Induced Autologous Chondrocyte Implantation Are Cost-Effective for Patellar Chondral Lesions

PURPOSE

To compare the cost-effectiveness of nonoperative management, particulated juvenile allograft cartilage (PJAC), and matrix-induced autologous chondrocyte implantation (MACI) in the management of patellar chondral lesions.

METHODS

A Markov model was used to evaluate the cost-effectiveness of three strategies for symptomatic patellar chondral lesions: 1) nonoperative management, 2) PJAC, and 3) MACI. Model inputs (transition probabilities, utilities, and costs) were derived from literature review and an institutional cohort of 67 patients treated with PJAC for patellar chondral defects (mean age 26 years, mean lesion size 2.7 cm²). Societal and payer perspectives over a 15-year time horizon were evaluated. The principal outcome measure was the incremental cost-effectiveness ratio (ICER) using a $100,000/quality-adjusted life year (QALY) willingness-to-pay threshold. Sensitivity analyses were performed to assess the robustness of the model and the relative effects of variable estimates on base case conclusions.

RESULTS

From a societal perspective, nonoperative management, PJAC, and MACI cost $4,140, $52,683, and $83,073 and were associated with 5.28, 7.22, and 6.92 QALYs gained, respectively. PJAC and MACI were cost-effective relative to nonoperative management (ICERs $25,010/QALY and $48,344/QALY, respectively). PJAC dominated MACI in the base case analysis by being cheaper and more effective, but this was sensitive to the estimated effectiveness of both strategies. PJAC remained cost-effective if PJAC and MACI were considered equally effective.

CONCLUSIONS

In the management of symptomatic patellar cartilage defects, PJAC and MACI were both cost-effective compared to nonoperative management. Because of the need for one surgery instead of two, and less costly graft material, PJAC was cheaper than MACI. Consequently, when PJAC and MACI were considered equally effective, PJAC was more cost-effective than MACI. Sensitivity analyses accounting for the lack of robust long-term data for PJAC or MACI demonstrated that the cost-effectiveness of PJAC versus MACI depended heavily on the relative probabilities of yielding similar clinical results.

LEVEL OF EVIDENCE

III, economic and decision analysis.

Intensity-modulated proton radiation therapy as a radical treatment modality for nasopharyngeal carcinoma in China: A cost-effectiveness analysis

BACKGROUND

Compared to conventional intensity-modulated photon radiation therapy (IMRT), intensity-modulated proton radiation therapy (IMPT) has potential to reduce irradiation-induced late toxicities while maintaining excellent tumor control in patients with nasopharyngeal carcinoma (NPC). However, the relevant cost-effectiveness remains controversial.

METHODS

A Markov decision tree analysis was performed under the assumption that IMPT offered normal tissue complication probability reduction (NTCP reduction) in long-term dysphagia, xerostomia, and hearing loss, compared to IMRT. Base-case evaluation was performed on T2N2M0 NPC of median age (43 years old). A Chinese societal willingness-to-pay threshold (33558 US dollars [$])/quality-adjusted life-year [QALY]) was adopted.

RESULTS

For patients at median age and having NTCP reduction of 10%, 20%, 30%, 40%, 50%, and 60%, their incremental cost-effectiveness ratios were $102684.0/QALY, $43161.2/QALY, $24134.7/QALY, $13991.6/QALY, $8259.8/QALY, and $4436.1/QALY, respectively; IMPT should provide an NTCP reduction of ≥24% to be considered cost-effective.

CONCLUSIONS

IMPT has potential to be cost-effective for average Chinese NPC patients and should be validated clinically.

Artificial Intelligence in Plastic Surgery: Applications and Challenges

New developments in artificial intelligence (AI) offer opportunities to enhance plastic surgery practice, research, and education. In this article, we review relevant AI tools and applications, including machine learning, reinforcement learning, and natural language processing. Our own Markov decision process for keloid treatment illustrates how these models are developed and can be used to enhance decision-making in clinical practice. Finally, we discuss challenges of implementing AI and knowledge gaps that must be addressed to successfully apply AI in plastic surgery. Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Understanding Health Economics in Spine Surgery

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The United States has faced substantial increases in health-care expenditure, with specifically large increases in spine surgery costs.

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Many different formulas are utilized to determine value in spine surgery, including cost- benefit analyses, cost-effectiveness analyses, and cost-utility analyses, with the overall determination of value being quality/cost.

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Quality often is calculated indirectly using either process measures or outcome measures and represents the potential benefit of a given intervention, usually over a specific time period to yield quality-adjusted life years.

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Costs are particularly difficult to calculate given the interhospital, regional, national, and global variability, as well as indirect costs of an intervention, and many different methods are utilized to estimate costs.

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Spine surgeons should be familiar with the elements that compose cost-effectiveness and their potential shortcomings in order for providers and health-care policy makers to identify the highest-quality studies and interventions that provide the greatest benefit to patients.

Total pancreatectomy with islet autotransplantation reduces resource utilization in pediatric patients

BACKGROUND

Chronic pancreatitis (CP) is associated with poor quality of life. Total pancreatectomy with islet autotransplantation (TPIAT) has traditionally been reserved for patients with refractory disease. We hypothesized TPIAT would lead to decreased costs and resource utilization after operation in children.

METHODS

Retrospective review of 39 patients who underwent TPIAT at a single children's hospital was performed. All inpatient admissions, imaging, endoscopic procedures, and operations were recorded for the year prior to and following operation. Costs were determined from Centers for Medicare and Medicaid Services.

RESULTS

Median hospital admissions before operation was 5 (IQR:2-7) and decreased to 2 (IQR:1-3) after (p < 0.01). Median total cost for the year before operation was $36,006 (IQR:$19,914-$47,680), decreasing to $24,900 postoperatively (IQR:$17,432-$44,005, p = 0.03). Removing cost of TPIAT itself, total cost was further reduced to $10,564 (IQR:$3096-$29,669, p < 0.01).

CONCLUSION

In children with debilitating CP, TPIAT has favorable impact on cost reduction, hospitalizations, and invasive procedures. Early intervention at a specialized pancreas center of excellence should be considered to decrease future resource utilization and costs among children.

Evidence-Based Medicine in Otolaryngology, Part XI: Modeling and Analysis to Support Decisions

OBJECTIVE

To provide a resource to educate clinical decision makers about the analyses and models that can be employed to support data-driven choices.

DATA SOURCES

Published studies and literature regarding decision analysis, decision trees, and models used to support clinical decisions.

REVIEW METHODS

Decision models provide insights into the evidence and its implications for those who make choices about clinical care and resource allocation. Decision models are designed to further our understanding and allow exploration of the common problems that we face, with parameters derived from the best available evidence. Analysis of these models demonstrates critical insights and uncertainties surrounding key problems via a readily interpretable yet quantitative format. This 11th installment of the Evidence-Based Medicine in Otolaryngology series thus provides a step-by-step introduction to decision models, their typical framework, and favored approaches to inform data-driven practice for patient-level decisions, as well as comparative assessments of proposed health interventions for larger populations.

CONCLUSIONS

Information to support decisions may arise from tools such as decision trees, Markov models, microsimulation models, and dynamic transmission models. These data can help guide choices about competing or alternative approaches to health care.

IMPLICATIONS FOR PRACTICE

Methods have been developed to support decisions based on data. Understanding the related techniques may help promote an evidence-based approach to clinical management and policy.

The cost-effectiveness of prostate health index for prostate cancer detection in Chinese men

BACKGROUND

Prostate-specific antigen (PSA) and prostate health index (PHI) have been used as biomarkers for prostate cancer detection. In this study, we aimed to evaluate the cost-effectiveness of PHI for prostate cancer detection in Chinese men.

METHOD

We developed a Markov model for Chinese male patient aged 50-75 years old. The PSA strategy was to offer TRUS-PB for all patients with elevated PSA of 4-10 ng/mL. The PHI strategy was to offer PHI for patients with elevated PSA of 4-10 ng/mL. TRUS-PB would only be offered for patients with PHI >35.0. Model inputs were extracted from local data when available. The cost per quality-adjusted life years gained for both strategies were calculated. The incremental cost-effectiveness ratios in relation to the willingness-to-pay (WTP) threshold were compared. One-way sensitivity analysis and probabilistic sensitivity analysis were performed. Cost-effectiveness acceptability curves were also constructed.

RESULTS

With a Markov model of 25 screening cycles from age 50 to 75 years, the mean total costs per man were estimated to be USD 27,439 in the PSA strategy and USD 22,877 in the PHI strategy. The estimated effects were estimated to be 15.70 in the PSA strategy and 16.05 in the PHI strategy. The PHI strategy was associated with an expected decrease in cost of USD 4562 and an expected gain of 0.35 QALY, resulting in an ICER of USD -13056.56. The results were shown to be robust upon one-way sensitivity analysis. Upon Monte Carlo simulation, the PHI strategy was more cost-effective for 100% of the iterations. The PHI strategy demonstrated dominance over the PSA strategy regardless of what WTP threshold we use.

CONCLUSIONS

A PHI-based screening strategy may be more cost-effective than a PSA-based strategy for prostate cancer detection in Chinese men. These results support consideration of a PHI-based approach for prostate cancer in Hong Kong.

Applications of machine learning in decision analysis for dose management for dofetilide

Background

Initiation of the antiarrhythmic medication dofetilide requires an FDA-mandated 3 days of telemetry monitoring due to heightened risk of toxicity within this time period. Although a recommended dose management algorithm for dofetilide exists, there is a range of real-world approaches to dosing the medication.

Methods and results

In this multicenter investigation, clinical data from the Antiarrhythmic Drug Genetic (AADGEN) study was examined for 354 patients undergoing dofetilide initiation. Univariate logistic regression identified a starting dofetilide dose of 500 mcg (OR 5.0, 95%CI 2.5–10.0, p<0.001) and sinus rhythm at the start of dofetilide loading (OR 2.8, 95%CI 1.8–4.2, p<0.001) as strong positive predictors of successful loading. Any dose-adjustment during loading (OR 0.19, 95%CI 0.12–0.31, p<0.001) and a history coronary artery disease (OR 0.33, 95%CI 0.19–0.59, p<0.001) were strong negative predictors of successful dofetilide loading. Based on the observation that any dose adjustment was a significant negative predictor of successful initiation, we applied multiple supervised approaches to attempt to predict the dose adjustment decision, but none of these approaches identified dose adjustments better than a probabilistic guess. Principal component analysis and cluster analysis identified 8 clusters as a reasonable data reduction method. These 8 clusters were then used to define patient states in a tabular reinforcement learning model trained on 80% of dosing decisions. Testing of this model on the remaining 20% of dosing decisions revealed good accuracy of the reinforcement learning model, with only 16/410 (3.9%) instances of disagreement.

Conclusions

Dose adjustments are a strong determinant of whether patients are able to successfully initiate dofetilide. A reinforcement learning algorithm informed by unsupervised learning was able to predict dosing decisions with 96.1% accuracy. Future studies will apply this algorithm prospectively as a data-driven decision aid.

Effect of treatment sequence on survival in stage IV rectal cancer with synchronous and potentially resectable liver metastases

BACKGROUND AND OBJECTIVES

The optimal treatment sequence in stage IV rectal cancer (RC) with synchronous liver metastases (SLM) remains undefined. Here, we compared outcomes between patients treated with the bowel-first approach (BFA) or the liver-first approach (LFA).

METHODS

Consecutive patients diagnosed with stage IV RC with SLM and who underwent complete resection were included. Both groups were matched using propensity scores. Differences in postoperative outcome, local control, and long-term survival were studied. In addition, a decision analysis (DA) model was built using TreeAge Pro to define the approach that results in the highest treatment completion rate.

RESULTS

During a 12-year period, 52 patients were identified, 21 and 31 of whom underwent the BFA and the LFA, respectively. Twenty-eight patients were matched; patients treated with the BFA experienced a longer median OS (50.0 vs 33.0 months; P = .40) and higher 5-year OS (42.9% vs 28.6%). The DA defined the BFA to be superior when the failure threshold (ie, no R0 resection, treatment discontinuation regardless of cause) for colectomy is less than 28.6%.

CONCLUSIONS

In stage IV rectal cancer with SLM, either the BFA or the LFA result in similar long-term outcomes. Treatment should be tailored according to clinicopathological variables.

Cost-effectiveness of liver transplantation in patients with colorectal metastases confined to the liver

BACKGROUND

Patients with non-resectable colorectal metastases are currently treated with chemotherapy. However, liver transplantation can increase the 5-year survival rate from 9 to 56 per cent if the cancer is confined to the liver. The aim of this study was to estimate the cost-effectiveness of liver transplantation for colorectal liver metastases.

METHODS

A Markov model with a lifetime perspective was developed to estimate the life-years, quality-adjusted life-years (QALYs), direct healthcare costs and cost-effectiveness for patients with non-resectable colorectal liver metastases who received liver transplantation or chemotherapy alone.

RESULTS

In non-selected cohorts, liver transplantation increased patients' life expectancy by 3·12 life-years (2·47 QALYs), at an additional cost of €209 143, giving an incremental cost-effectiveness ratio (ICER) of €67 140 per life-year (€84 667 per QALY) gained. In selected cohorts (selection based on tumour diameter, time since primary cancer, carcinoembryonic antigen levels and response to chemotherapy), the effect of liver transplantation increased to 4·23 life-years (3·41 QALYs), at a higher additional cost (€230 282), and the ICER decreased to €54 467 per life-year (€67 509 per QALY) gained. Given a willingness to pay of €70 500, the likelihood of transplantation being cost-effective was 0·66 and 0·94 (0·23 and 0·67 QALYs) for non-selected and selected cohorts respectively.

CONCLUSION

Liver transplantation was cost-effective but only for highly selected patients. This might be possible in countries with good access to grafts and low waiting list mortality.

Analyzing cost-effectiveness of neural-monitoring in recurrent laryngeal nerve recovery course in thyroid surgery

PURPOSE

The increasing use of intraoperative neural monitoring (IONM) of the recurrent laryngeal nerve (RLN) during thyroid surgery imposes an evaluation of cost-effectiveness.

METHODS

The analysis estimated the cost versus utility of different alternatives that simulate nerve injury course and the consequences for the following cohorts of patients: (1) no RLN injury, or vocal fold palsy (VCP) recovery within 1 month (2), 2 months (3), 6 months (4), and after 12 months (5). In the model applied, the average simulated cohort consisted of a young female patient, 40 years old, employed, daily voice user, who underwent elective, conventional total thyroidectomy via cervical incision using a standardized intermittent IONM technique, for an operable benign, bilateral, diffuse, multinodular, non-toxic, non-retrosternal goiter.

RESULTS

IONM was cost-ineffective when parameters such as the rates of transient vocal fold palsy (VCP) reached 38.5%. IONM was cost-effective if the rate of VCP was 33.6% at 1 month, 22.9% at 2 months, 9.8% at 6 months, and 3.8% at 12 months, independent of phono-surgery. The described scenario is cost-effective only in a high-volume setting.

CONCLUSIONS

This study used simulation economic modeling to assess clinical and cost-effectiveness utility of IONM implementation. In light of the limitations of a simulation-based study, we conclusively assumed that IONM is cost-effective for permeant RLN injuries.

Decision-Making in Critical Limb Ischemia: A Markov Simulation

BACKGROUND

Critical limb ischemia (CLI) is a feared complication of peripheral vascular disease that often requires surgical management and may require amputation of the affected limb. We developed a decision model to inform clinical management for a 63-year-old woman with CLI and multiple medical comorbidities, including advanced heart failure and diabetes.

METHODS

We developed a Markov decision model to evaluate 4 strategies: amputation, surgical bypass, endovascular therapy (e.g. stent or revascularization), and medical management. We measured the impact of parameter uncertainty using 1-way, 2-way, and multiway sensitivity analyses.

RESULTS

In the base case, endovascular therapy yielded similar discounted quality-adjusted life months (26.50 QALMs) compared with surgical bypass (26.34 QALMs). Both endovascular and surgical therapies were superior to amputation (18.83 QALMs) and medical management (11.08 QALMs). This finding was robust to a wide range of periprocedural mortality weights and was most sensitive to long-term mortality associated with endovascular and surgical therapies. Utility weights were not stratified by patient comorbidities; nonetheless, our conclusion was robust to a range of utility weight values.

CONCLUSIONS

For a patient with CLI, endovascular therapy and surgical bypass provided comparable clinical outcomes. However, this finding was sensitive to long-term mortality rates associated with each procedure. Both endovascular and surgical therapies were superior to amputation or medical management in a range of scenarios.

Socioeconomic disparities, financial toxicity, and opportunities for enhanced system efficiencies for patients with cancer

Cancer care continues to stress the US healthcare system with increases in life expectancy, cancer prevalence, and survivors' complex needs. These challenges are compounded by socioeconomic, racial, and cultural disparities that are associated with poor clinical outcomes. One innovative and resource-wise strategy to address this demand on the system is expanded use of telehealth. This paradigm has the potential to decrease healthcare and patient out-of-pocket costs and improve patient adherence to recommended treatment and/or surveillance.