Markov Decision Analysis Research Articles

Comparative Effectiveness of Lymphadenectomy Strategies During Curative Resection for Gastric Adenocarcinoma

BackgroundThe purpose of this study was to compare the long-term effectiveness of three lymphadenectomy strategies in patients with gastric cancer. We hypothesized that, compared with the traditional standard (D2) lymph node dissection strategy, the less aggressive modified standard (mD2) lymphadenectomy may offer superior effectiveness due to reduced operative morbidity and comparable long-term recurrence-free survival. MethodsA Markov decision analysis model was created to simulate 5-year outcomes across three lymphadenectomy approaches for gastric cancer: limited regional (D1), traditional standard (D2), and modified standard (mD2). The primary outcome was discounted quality-adjusted life-years (dQALY). Model variable estimates were derived from outcomes data and quality of life estimates published in Europe and America within the last 15 years. One-way and probabilistic sensitivity analyses were performed for clinically relevant variables. ResultsThe mD2 lymphadenectomy offered 3.03 dQALY over 5 years, outperforming D2 (2.62 dQALY) and D1 (2.37 dQALY). Monte Carlo simulations indicated that both mD2 and D2 lymph node dissection strategies outperformed D1 in 94.9% of simulations. Sensitivity analyses demonstrated that the mD2 approach would be less effective than D2 if the perioperative mortality rate of mD2 was greater than 6.9% (3.2% baseline). ConclusionsAcross modern series, the modified standard mD2 lymphadenectomy is an effective alternative to the traditional D2 lymphadenectomy for patients with gastric cancer. A D1-limited regional lymphadenectomy is not recommended during gastric cancer resection.

Robot-assisted unicompartmental knee arthroplasty for patients with isolated medial compartment osteoarthritis is cost-effective

The primary aim of the study was to perform an analysis to identify the cost per quality-adjusted life-year (QALY) of robot-assisted unicompartmental knee arthroplasty (rUKA) relative to manual total knee arthroplasty (TKA) and unicompartmental knee arthroplasty (UKA) for patients with isolated medial compartment osteoarthritis (OA) of the knee. Secondary aims were to assess how case volume and length of hospital stay influenced the relative cost per QALY. A Markov decision analysis was performed, using known parameters for costs, outcomes, implant survival, and mortality, to assess the cost-effectiveness of rUKA relative to manual TKA and UKA for patients with isolated medial compartment OA of the knee with a mean age of 65 years. The influence of case volume and shorter hospital stay were assessed. Using a model with an annual case volume of 100 patients, the cost per QALY of rUKA was £1395 and £1170 relative to TKA and UKA, respectively. The cost per QALY was influenced by case volume: a low-volume centre performing ten cases per year would achieve a cost per QALY of £7170 and £8604 relative to TKA and UKA. For a high-volume centre performing 200 rUKAs per year with a mean two-day length of stay, the cost per QALY would be £648; if performed as day-cases, the cost would be reduced to £364 relative to TKA. For a high-volume centre performing 200 rUKAs per year with a shorter length of stay of one day relative to manual UKA, the cost per QALY would be £574. rUKA is a cost-effective alternative to manual TKA and UKA for patients with isolated medial compartment OA of the knee. The cost per QALY of rUKA decreased with reducing length of hospital stay and with increasing case volume, compared with TKA and UKA. Cite this article: Bone Joint J 2019;101-B:1063-1070.

Personalized Pancreatic Cancer Management: A Systematic Review of How Machine Learning Is Supporting Decision-making.

This review critically analyzes how machine learning is being used to support clinical decision-making in the management of potentially resectable pancreatic cancer. Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines, electronic searches of MEDLINE, Embase, PubMed, and Cochrane Database were undertaken. Studies were assessed using the checklist for critical appraisal and data extraction for systematic reviews of prediction modeling studies (CHARMS) checklist. In total 89,959 citations were retrieved. Six studies met the inclusion criteria. Three studies were Markov decision-analysis models comparing neoadjuvant therapy versus upfront surgery. Three studies predicted survival time using Bayesian modeling (n = 1) and artificial neural network (n = 1), and one study explored machine learning algorithms including Bayesian network, decision trees, k-nearest neighbor, and artificial neural networks. The main methodological issues identified were limited data sources, which limits generalizability and potentiates bias; lack of external validation; and the need for transparency in methods of internal validation, consecutive sampling, and selection of candidate predictors. The future direction of research relies on expanding our view of the multidisciplinary team to include professionals from computing and data science with algorithms developed in conjunction with clinicians and viewed as aids, not replacement, to traditional clinical decision-making.

Markov decision analysis of neoadjuvant treatment pathway versus surgery first pathway for resectable pancreatic cancer.

456 Background: Surgery first (SF) versus neoadjuvant approach (NAT) to management of potentially resectable pancreatic ductal adenocarcinoma (PDAC) is controversial. This study is unique in utilizing institutional data to offer Markov decision-analysis of overall treatment pathways for resectable PDAC. Methods: An advanced Markov decision analysis model was constructed and populated with data from a retrospective institutional database. Patients presenting with resectable PDAC from 2008-2012 were included in the SF arm. Those presenting with resectable PDAC from 2012-2016 and treated within NAT pathway populated the NAT arm. Model uncertainties were tested with one and two-way deterministic sensitivity analysis and probabilistic Monte Carlo sensitivity analysis set to 1000 cycles with variables altered between highest and lowest observed values. Results: NAT pathway gave an additional 0.58 QALMs (22.43 vs. 21.85 QALMs). Monte Carlo analysis reported indifference between treatment strategies. One-way deterministic sensitivity analysis showed that probability of resection in the SF pathway must be greater than 0.82, or below 0.72 in NAT pathway, and probability of receiving adjuvant therapy above 0.6 to alter pathway superiority. Two-way deterministic sensitivity analysis demonstrated treatment superiority depended on resection rate in each pathway and receiving adjuvant therapy in SF pathway. Markov cohort analysis demonstrated superiority of neoadjuvant pathway (Table). Conclusions: Optimal treatment pathway remains debatable on an intention-to-treat Markov decision analysis. Markov cohort analysis of treatment received demonstrated benefit with NAT pathway. [Table: see text]

Comparative Effectiveness of Resection vs Surveillance for Pancreatic Branch Duct Intraductal Papillary Mucinous Neoplasms With Worrisome Features

Importance The 2012 international consensus guidelines defined a subcategory of pancreatic branch duct intraductal papillary mucinous neoplasms with “worrisome features,” which may be followed with close surveillance. However, given the poor prognosis of invasive malignancy, the role of early, upfront resection requires further investigation. Objective To compare the utility of upfront resection vs long-term surveillance. We hypothesized that surveillance of these cystic neoplasms would offer greater long-term utility. Design, Setting, and Participants A Markov decision analysis model was constructed to estimate and compare 2 management strategies: early resection and long-term surveillance. Estimates for the utility of outcomes, probabilities of transitions between disease states, and probabilities of surgical morbidity were derived from a literature review of articles published between 1997 and 2014. The comparative effectiveness model’s variable estimates were based on data published predominantly by high-volume, tertiary referral centers. Model probability variable estimates were derived from large, retrospective, single-institution reports. For utility variables, estimates derived from studies using standard-gamble or time-tradeoff methods were given greater weight. Main Outcomes and Measures Expected utility was measured in terms of quality-adjusted life years using 3% annual discount. Probabilistic and 1-way sensitivity analyses were performed to assess the potential effects of uncertainty in estimates of key model variables. Results Early resection yielded 11.63 quality-adjusted life-years during 20 years of follow-up compared with 11.06 for surveillance. Probabilistic sensitivity analysis indicated that resection has a 94% likelihood of being more effective than surveillance. Early resection obtained greater utility only if each of the following criteria are met: life expectancy is at least 18 years, surgical mortality is less than 4.3%, and baseline preoperative utility is at least 0.78. Additional drivers of the model outcomes include the rate of progression from worrisome to high-risk features and the likelihood of finding cancer on resection for neoplasms with high-risk stigmata. Conclusions and Relevance Early resection compares favorably with surveillance in the management of branch duct intraductal papillary mucinous neoplasms with worrisome features. However, careful consideration of patient factors and surgeon outcomes is imperative.

Potential Consequences of Not Using Live Attenuated Influenza Vaccine

Decreased live attenuated influenza vaccine (LAIV) effectiveness in the U.S. prompted the Advisory Committee on Immunization Practices in August 2016 to recommend against this vaccine's use. However, overall influenza uptake increases when LAIV is available and, unlike the U.S., LAIV has retained its effectiveness in other countries. These opposing countercurrents create a dilemma. To examine the potential consequences of the decision to not recommend LAIV, which may result in decreased influenza vaccination coverage in the U.S. population, a Markov decision analysis model was used to examine influenza vaccination options in U.S. children aged 2-8 years. Data were compiled and analyzed in 2016. Using recently observed low LAIV effectiveness values, fewer influenza cases will occur if LAIV is not used compared with having LAIV as a vaccine option. However, having the option to use LAIV may be favored if LAIV effectiveness returns to prior levels or if the absence of vaccine choice substantially decreases overall vaccine uptake. Continued surveillance of LAIV effectiveness and influenza vaccine uptake is warranted, given their importance in influenza vaccination policy decisions.

CSM 2017 Orthopaedic Section Platform Presentations (Abstracts OPL1–OPL64)

CSM 2017 Orthopaedic Section Platform Presentations (Abstracts OPL1–OPL64)

Cost-Effectiveness of the 4 Pillars Practice Transformation Program to Improve Vaccination of Adults Aged 65 and Older.

To estimate the cost-effectiveness of an intervention to increase pneumococcal, influenza, and pertussis-containing vaccine uptake in adults aged 65 and older in primary care practices. Markov decision analysis model, comparing the cost-effectiveness of the 4 Pillars Practice Transformation Program with no intervention. Diverse primary care practices in two U.S. cities. Clinical trial participants aged 65 and older. Quality-adjusted life years (QALYs), public health outcomes, and costs. Vaccination rates and intervention costs were derived from a randomized controlled cluster trial. Other parameters were derived from the medical literature and Centers for Disease Control and Prevention data. All parameters were individually and simultaneously varied over their distributions. With the intervention program and extrapolating over 10 years, there would be approximately 60,920 fewer influenza cases, 2,031 fewer pertussis cases, and 13,842 fewer pneumococcal illnesses in adults aged 65 and older. Total per-person vaccination and illness costs with the intervention were $23.93 higher than without the intervention, with a concurrent increase in effectiveness of 0.0031 QALYs, or $7,635 per QALY gained. In sensitivity analyses, no individual parameter variation caused the intervention to cost more than $50,000 per QALY gained. Implementing an intervention based on the 4 Pillars Practice Transformation Program is a cost-effective undertaking in primary care practices for individuals aged 65 and older, with predicted public health benefits.

Revascularization of smokers with claudication is not predicted to limit quality of life despite a higher risk of late failure

ObjectiveTobacco smoking after lower extremity revascularization for claudication has repeatedly been shown to increase the risk of adverse events, such that many vascular specialists consider that refusal to abstain from smoking constitutes a major contraindication to open surgical bypass or endovascular intervention. MethodsA Markov decision analysis (DA) model was used to compare the options of direct revascularization vs medical therapy only in smokers with claudication. The primary outcome was calculated quality of life (cQoL), determined for each patient at follow-up based on the outcomes of the treatment received. Markov DA software was used to predict the QoL for each treatment option preoperatively based on smoking status. ResultsAmong patients referred during a recent 64-month period with vasculogenic claudication, 94 were actively smoking compared with 217 who were not. The DA model predicted that if the patients who smoked were to discontinue smoking, the best therapy would be bypass surgery for 77% and endovascular intervention for 17%. However, despite at least doubling the risks with intervention in the patients who continue to smoke, the DA model still predicted that 78% and 9% would fare better with open surgical or endovascular intervention, respectively. Among actively smoking patients, open surgical (3%) or endovascular (4%) therapies were initially performed in few patients, whereas 93% were offered only medical therapy. Among initial nonsmokers, revascularization was performed by open (27%) or endovascular (42%) means. At 3 years, the median (interquartile range [IQR]) cQoL was lower in initial smokers than in nonsmokers (0.73 [IQR, 0.73-0.77] vs 0.82 [IQR, 0.75-0.86]; P < .0001), primarily because of a lack of revascularization for smokers. Among initial smokers who did undergo revascularization initially, because of progression of symptoms, or after smoking cessation, cQoL was similar to initial nonsmokers (0.77 [IQR, 0.73-0.84] vs 0.73 [IQR, 0.73-0.73]; P = .37). Although 26% of initial smokers had stopped by the time of their last follow-up, 10% of initially nonsmoking patients were smoking at follow-up. However, among all patients undergoing intervention, the cQoL of patients smoking at the time of last their follow-up was similar to nonsmokers (0.82 [IQR, 0.82-0.86] vs 0.83 [IQR, 0.73-0.86]; P = .99). ConclusionsPatients with claudication who smoke may be denied the symptom improvement associated with revascularization, yet recidivism for smoking also occurs among patients who have stopped smoking in order to receive revascularization. The strategy not to directly revascularize patients with claudication who continue to smoke does not appear to maximize patient midterm QoL.

Neoadjuvant therapy versus upfront surgical strategies in resectable pancreatic cancer: A Markov decision analysis

BackgroundNeoadjuvant therapy is gaining acceptance as a valid treatment option for borderline resectable pancreatic cancer; however, its value for clearly resectable pancreatic cancer remains controversial. The aim of this study was to use a Markov decision analysis model, in the absence of adequately powered randomized trials, to compare the life expectancy (LE) and quality-adjusted life expectancy (QALE) of neoadjuvant therapy to conventional upfront surgical strategies in resectable pancreatic cancer patients. MethodsA Markov decision model was created to compare two strategies: attempted pancreatic resection followed by adjuvant chemoradiotherapy and neoadjuvant chemoradiotherapy followed by restaging with, if appropriate, attempted pancreatic resection. Data obtained through a comprehensive systematic search in PUBMED of the literature from 2000 to 2015 were used to estimate the probabilities used in the model. Deterministic and probabilistic sensitivity analyses were performed. ResultsOf the 786 potentially eligible studies identified, 22 studies met the inclusion criteria and were used to extract the probabilities used in the model. Base case analyses of the model showed a higher LE (32.2 vs. 26.7 months) and QALE (25.5 vs. 20.8 quality-adjusted life months) for patients in the neoadjuvant therapy arm compared to upfront surgery. Probabilistic sensitivity analyses for LE and QALE revealed that neoadjuvant therapy is favorable in 59% and 60% of the cases respectively. Conclusion(s)Although conceptual, these data suggest that neoadjuvant therapy offers substantial benefit in LE and QALE for resectable pancreatic cancer patients. These findings highlight the value of further prospective randomized trials comparing neoadjuvant therapy to conventional upfront surgical strategies.

Periodic limb movements of sleep: empirical and theoretical evidence supporting objective at-home monitoring.

IntroductionPeriodic limb movements of sleep (PLMS) may increase cardiovascular and cerebrovascular morbidity. However, most people with PLMS are either asymptomatic or have nonspecific symptoms. Therefore, predicting elevated PLMS in the absence of restless legs syndrome remains an important clinical challenge.MethodsWe undertook a retrospective analysis of demographic data, subjective symptoms, and objective polysomnography (PSG) findings in a clinical cohort with or without obstructive sleep apnea (OSA) from our laboratory (n=443 with OSA, n=209 without OSA). Correlation analysis and regression modeling were performed to determine predictors of periodic limb movement index (PLMI). Markov decision analysis with TreeAge software compared strategies to detect PLMS: in-laboratory PSG, at-home testing, and a clinical prediction tool based on the regression analysis.ResultsElevated PLMI values (>15 per hour) were observed in >25% of patients. PLMI values in No-OSA patients correlated with age, sex, self-reported nocturnal leg jerks, restless legs syndrome symptoms, and hypertension. In OSA patients, PLMI correlated only with age and self-reported psychiatric medications. Regression models indicated only a modest predictive value of demographics, symptoms, and clinical history. Decision modeling suggests that at-home testing is favored as the pretest probability of PLMS increases, given plausible assumptions regarding PLMS morbidity, costs, and assumed benefits of pharmacological therapy.ConclusionAlthough elevated PLMI values were commonly observed, routinely acquired clinical information had only weak predictive utility. As the clinical importance of elevated PLMI continues to evolve, it is likely that objective measures such as PSG or at-home PLMS monitors will prove increasingly important for clinical and research endeavors.

Reconsidering adjuvant versus salvage radiation therapy for prostate cancer in the genomics era.

We developed a decision analysis framework to simulate the clinical choice of early adjuvant versus delayed salvage radiation therapy after radical prostatectomy. We designed a Markov decision analysis model to represent two alternative treatment approaches for prostate cancer after prostatectomy over a 10-year time horizon. The model contained individualized inputs including genomic classifier score. Sensitivity analyses were performed to evaluate model results. Observation with delayed salvage radiation is preferred according to the base case, with greater average length and quality of life. However, adjuvant therapy is preferred over observation with salvage when genomics-based estimates of recurrence are high. Model results were sensitive to genomics-based estimates of cancer recurrence and to nonprostate cancer mortality.

Massachusetts Health Reform Cost Less and Was More Effective for Uninsured Individuals With Venous Thromboembolism: A Cost-Effectiveness Analysis.

Patients with venous thromboembolism (VTE) require access to comprehensive physician and pharmacy benefits to prevent recurrence and hemorrhage. Before 2006, Massachusetts provided these benefits through a program restricted to safety net hospitals called Free Care. Providing portable health insurance through Massachusetts health reform could improve outcomes for uninsured with VTE but its cost-effectiveness is unknown. We constructed a Markov decision analysis model comparing our conceptualization of the Massachusetts health reform (health reform strategy) to no health reform strategy for a patient beginning warfarin for new episode of VTE. In the model, a patient may develop recurrent VTE or develop hemorrhage or stop warfarin after 6 months if no event occurs. To measure effectiveness, we analyzed laboratory data from Boston Medical Center, the largest safety net hospital in Massachusetts. Specifically, we measured the probability of having a subtherapeutic warfarin level for patients newly insured compared with those on Free Care prereform adjusting for secular trends. To calculate inpatient costs, we used the Health Care Utilization Project. We then calculated the incremental cost-effectiveness ratio for the health reform strategy adjusted to 2014 USD per quality-adjusted life-year (QALY) and performed sensitivity analyses. The health reform strategy cost less and gained more QALYs than the no health reform strategy. Our result was most sensitive to the odds that Health Reform protected against a subtherapeutic warfarin level, the cost of Health Reform, and the percentage of total health care costs attributable to VTE in Massachusetts. The health reform strategy cost less and was more effective than the no health reform strategy for patients with VTE.

Decision Analysis of Postremission Therapy in Cytogenetically Intermediate-Risk Acute Myeloid Leukemia: The Impact of FLT3 Internal Tandem Duplication, Nucleophosmin, and CCAAT/Enhancer Binding Protein Alpha

We performed a decision analysis comparing allogeneic hematopoietic cell transplantation (allo-HCT) versus chemotherapy in first complete remission for patients with cytogenetically intermediate-risk acute myeloid leukemia, depending on the presence or absence of FLT3-internal tandem duplication (ITD), nucleophosmin (NPM1), and CCAAT/enhancer binding protein alpha (CEBPA) mutations. Adjusted means of the patient-reported EQ-5D index were used as quality-of-life (QOL) estimates. In 332 patients for which FLT3-ITD status was available, FLT3-ITD was present in 60. In 272 patients without FLT3-ITD, NPM1 mutations were present in 83. CEBPA biallelic mutations were detected in 53 patients. For patients harboring FLT3-ITD, allo-HCT improved life expectancy (LE) (52 versus 32 months during 10-year observation) and QOL-adjusted life expectancy (QALE, 36 versus 21). Monte-Carlo simulation identified allo-HCT as the favored strategy in 100% of simulations. In patients without FLT3-ITD, allo-HCT improved LE/QALE with or without NPM1 mutations. However, sensitivity analyses showed that the results were not robust enough. For patients harboring CEBPA biallelic mutations, chemotherapy was favored (LE, 53 versus 84; QALE, 37 versus 59), whereas, for patients with monoallelic mutations or wild-type CEBPA, allo-HCT was favored (LE, 68 versus 54; QALE, 48 versus 37). Sensitivity analyses did not change the results in either group. In conclusion, based on a Markov decision analysis, allo-HCT was a favored postremission strategy in patients with FLT3-ITD, and chemotherapy was favored in patients with biallelic CEBPA mutations. A prospective study is warranted to determine the value of allo-HCT, especially in FLT3-ITD–negative patients.

Timing of bariatric surgery for severely obese adolescents: a Markov decision-analysis

PurposeAlthough controversial, bariatric surgery is increasingly being performed in adolescents. We developed a model to simulate the effect of timing of gastric bypass in obese adolescents on quantity and quality of life. MethodsA Markov state-transition model was constructed comparing two treatment strategies: gastric bypass surgery at age 16 versus delayed surgery in adulthood. The model simulated a hypothetical cohort of adolescents with body mass index of 45kg/m2. Model inputs were derived from current literature. The main outcome measure was quality and quantity of life, measured using quality-adjusted life–years (QALYs). ResultsFor females, early gastric bypass surgery was favored by 2.02 QALYs compared to delaying surgery until age 35 (48.91 vs. 46.89 QALYs). The benefit was even greater for males, where early surgery was favored by 2.9 QALYs (48.30 vs. 45.40 QALYs). The absolute benefit of surgery at age 16 increased; the later surgery was delayed into adulthood. Sensitivity analyses demonstrated that adult surgery was favored only when the values for adverse events were unrealistically high. ConclusionsIn our model, early gastric bypass in obese adolescents improved both quality and quantity of life. These findings are useful for surgeons and pediatricians when counseling adolescents considering weight loss surgery.

Markov decision process for comparative economic analysis of immunization strategies against hepatitis A virus

Hepatitis A vaccination in the U.S. is currently universally recommended for all children between the ages of one and two years. Several nations have vaccination strategies which target high-risk groups or children who live in areas with high incidence rates of the disease, but developing countries often have no recommendations due to their poor economic conditions and the effect this may have on access to vaccinations. This study uses Markov decision process for baseline cost utility and comparative effectiveness analyses of various vaccination strategies to counter hepatitis A virus between a developed country (U.S.) and a developing country (Mexico). Treeage Pro Healthcare software was employed in Markov decision analysis. Secondary data was utilized in the model from available literature. Results showed that for the U.S., the universal vaccination strategy was the most cost effective while the no vaccination strategy was the lowest cost. Whereas, for Mexico the effectiveness for both no vaccination and universal strategies were almost the same, however, the cost of no vaccination was the lowest. The results could alter hepatitis A vaccination guidelines and decrease the large amount of indirect and directs costs of the disease, while also potentially eradicating the severe cases or deaths that occur as a result of infection.

Can Robot-Assisted Unicompartmental Knee Arthroplasty Be Cost-Effective? A Markov Decision Analysis

BackgroundUnicompartmental knee arthroplasty (UKA) is a treatment option for single-compartment knee osteoarthritis. Robotic assistance may improve survival rates of UKA, but the cost-effectiveness of robot-assisted UKA is unknown. The purpose of this study was to delineate the revision rate, hospital volume, and robotic system costs for which this technology would be cost-effective. MethodsWe created a Markov decision analysis to evaluate the costs, outcomes, and incremental cost-effectiveness of robot-assisted UKA in 64-year-old patients with end-stage unicompartmental knee osteoarthritis. ResultsRobot-assisted UKA was more costly than traditional UKA, but offered a slightly better outcome with 0.06 additional quality-adjusted life-years at an incremental cost of $47,180 per quality-adjusted life-years, given a case volume of 100 cases annually. The system was cost-effective when case volume exceeded 94 cases per year, 2-year failure rates were below 1.2%, and total system costs were <$1.426 million. ConclusionRobot-assisted UKA is cost-effective compared with traditional UKA when annual case volume exceeds 94 cases per year. It is not cost-effective at low-volume or medium-volume arthroplasty centers.

Ship design evaluation subject to carbon emission policymaking using a Markov decision process framework

This paper outlines a novel ship design evaluation framework rooted in Markov decision analysis and derived metrics. The framework synthesizes concepts from dynamic network optimization, decision theory, and scenario analysis to holistically manage exogenous uncertainty and value ship system changeability. A Markov decision process is used to analyze development and operational paths over a ship׳s life cycle and to identify system characteristics consistent within high performing designs. Decision metrics then contextualize a fuller extent of design engineer and operator preferences toward tradeoffs between value creation and active ship management. The case study specifically examines future scenarios subject to carbon emission regulations and uncertainty surrounding enforcement of the Energy Efficient Design Index. Results inform decisions about when, where, and how to incorporate the changeability that maximizes expected life cycle rewards.

Cost-effectiveness analysis reveals microsurgical varicocele repair is superior to percutaneous embolization in the treatment of male infertility.

Varicoceles are a common cause of male infertility; repair can be accomplished using either surgical or radiological means. We compare the cost-effectiveness of the gold standard, the microsurgical varicocele repair (MV), to the options of a nonmicrosurgical approach (NMV) and percutaneous embolization (PE) to manage varicocele-associated infertility. A Markov decision-analysis model was developed to estimate costs and pregnancy rates. Within the model, recurrences following MV and NMV were re-treated with PE and recurrences following PE were treated with repeat PE, MV or NMV. Pregnancy and recurrence rates were based on the literature, while costs were obtained from institutional and government supplied data. Univariate and probabilistic sensitivity-analyses were performed to determine the effects of the various parameters on model outcomes. Primary treatment with MV was the most cost-effective strategy at $5402 CAD (Canadian)/pregnancy. Primary treatment with NMV was the least costly approach, but it also yielded the fewest pregnancies. Primary treatment with PE was the least cost-effective strategy costing about $7300 CAD/pregnancy. Probabilistic sensitivity analysis reinforced MV as the most cost-effective strategy at a willingness-to-pay threshold of >$4100 CAD/pregnancy. MV yielded the most pregnancies at acceptable levels of incremental costs. As such, it is the preferred primary treatment strategy for varicocele-associated infertility. Treatment with PE was the least cost-effective approach and, as such, is best used only in cases of surgical failure.

How Much Does the Type of Tympanostomy Tube Matter? A Utility‐Based Markov Decision Analysis

Objectives: Different types of tympanostomy tubes (TT) are available to the otolaryngologist with relative advantages and disadvantages. The objectives of this study are: (1) Use a utility-based Markov Decision Analysis model to compare outcomes of short-term grommet tubes, “intermediate” type tubes (Triune, Grace Medical, USA), and “permanent” T-Tubes. (2) Use sensitivity analysis to determine the most important factors influencing outcomes with one type of TT versus another. Methods: A Markov cohort decision analysis model was created using computer software (Treeage Software, Inc. USA) comparing the 3 types of TT. Published data were used to determine key baseline model parameters. The model featured potential complications including eardrum perforation, early TT extrusion, and the need for possible repeat TT placement after extrusion. Outcomes were quantified using a 0.95 (one procedure, full recovery) to 0.6 (failed myringoplasty) utility scale. Utility values were discounted over time to incorporate real life inconvenience. Statistical analysis included simple descriptive statistics and contingency tables. Results: The intermediate TT accumulated superior total utility in 2-, 4-, and 6-year models (2.48, 3.96, and 5.27 total utility) compared with grommets (2.32,3.82,5.18) and T-tubes (2.42, 3.86, 5.18). Examining a hypothetical 3000 child cohort, T-tubes resulted in an increased overall perforation rate (10.5% versus 2.0%, P &lt; .001 chi-squared). Sensitivity analysis indicated that the rate of repeat TT placement and the inconvenience utility discount factor over time were the driving factors of the model. Conclusions: The intermediate TT may produce favorable outcomes as it combines a balance of a lower perforation rate than T-tubes and a longer period of ventilation than grommet tubes.