Estimated impact and value of blood-based colorectal cancer screening at varied adherence compared with stool-based screening

Objective: This analysis estimated the outcomes of triennial blood-based colorectal cancer (CRC) screening at various adherence, including perfect adherence, compared with triennial multi-target stool DNA (mt-sDNA) screening at the reported real-world adherence rate.Methods: The validated CRC-AIM model simulated a US cohort of average-risk individuals receiving triennial screening with mt-sDNA or blood-based test from ages 45-75 years. Modeled specificity and sensitivity were based on reported data. Adherence was set at a real-world rate of 65.6% for mt-sDNA and at 65.6%, relative 10% incremental increases from 65.6%, or 100% for the blood-based test. Costs of mt-sDNA and the blood-based test were based on prices for clinically available tests ($508.87 and $895, respectively). Value-based pricing was estimated at a willingness-to-pay threshold of $100,000.Results: Both tests resulted in life-years gained (LYG), reduced CRC cases, and reduced deaths versus no screening. With adherence for mt-sDNA set at 65.6% and for blood-based test set at 100%, mt-sDNA resulted in 30% more LYG, 52% more averted CRC cases, and 32% more averted CRC deaths. At reported sensitivity and specificity rates, mt-sDNA at 65.6% adherence dominates (is more effective and less costly) the blood-based test at any adherence. There was no price at which triennial screening with the blood-based test at any adherence was cost-effective compared with mt-sDNA at 65.6% adherence.Conclusions: Triennial screening with mt-sDNA resulted in better clinical outcomes at a lower cost compared with the modeled blood-based test even at perfect adherence, supporting application of blood-based tests only as a secondary screening option.

Trends in colorectal cancer screening from the National Health Interview Survey (NHIS): analysis of the impact of different modalities on overall screening rates

Colorectal cancer (CRC) is the second leading cause of cancer-related mortality in adults in the United States. Despite compelling evidence of improved outcomes in CRC, screening rates are not optimal. This study aimed to characterize CRC screening trends over the last two decades and assess the impact of various screening modalities on overall CRC screening rates. Using National Health Interview Survey data from 2005-2021, we examined CRC screening (colonoscopy, mt-sDNA, FOBT/FIT, sigmoidoscopy, CT Colonography) rates among adults aged 50-75 years (n = 85,571). A pseudo-time-series cross-sectional (pseudo-TSCS) analysis was conducted including a random effects GLS regression model to estimate the relative impact of each modality on changes in CRC screening rates. Among 50-75-year-olds, the estimated CRC screening rate increased from 47.7% in 2005 to 69.9% in 2021, with the largest increase between 2005 and 2010 (47.7% to 60.7%). Rates subsequently plateaued until 2015 but increased from 63.5% in 2015 to 69.9% in 2018. This was primarily driven by the increased use of mt-sDNA (2.5% in 2018 to 6.6% in 2021). Pseudo-TSCS analysis results showed that mt-sDNA contributed substantially to the increase in overall screening rates (77.3%; p < 0.0001) between 2018-2021. While CRC screening rates increased from 2005 to 2021, they remain below the 80% goal. The introduction of mt-sDNA, a non-invasive screening test may have improved overall rates. Sustained efforts are required to further increase screening rates to improve patient outcomes and offering a range of screening options is likely to contribute to achieving this goal.

Estimated Average-Risk Colorectal Cancer Screening-Eligible Population in the US

This cross-sectional study estimates the number of average-risk colorectal cancer screening–eligible individuals in the US since the US Preventive Services Task Force updated its recommendations in 2021.

Impact of Eliminating Cost-Sharing by Medicare Beneficiaries for Follow-Up Colonoscopy After a Positive Stool-based Colorectal Cancer Screening Test

Medicare coverage of a follow-up colonoscopy after a positive stool-based colorectal cancer screening test with no patient cost-sharing started January 2, 2023, which may favorably affect screening behavior. This analysis estimated the clinical and economic effects of increased colorectal cancer screening participation potentially resulting from this policy change in Medicare beneficiaries. The validated Colorectal Cancer and Adenoma Incidence & Mortality (CRC-AIM) model simulated three guideline-endorsed colorectal cancer screening strategies for average-risk individuals (colonoscopy every 10 years, annual fecal immunochemical test, triennial multitarget stool DNA) from ages 65-75 years. The base-case scenario assumed 0% coinsurance for initial screening and follow-up colonoscopy, real-world screening test use (colonoscopy = 45.3%, stool-based test = 24.4%, unscreened = 30.3%), and real-world follow-up colonoscopy rates. Comparative scenarios assumed an increase in the overall screening rate from 0% to 15% (5% increments) and an increase in the follow-up colonoscopy rate from 0% to 15% (5% increments). The base-case scenario resulted in 128 life-years gained (LYG)/1,000 individuals versus no screening and total screening and treatment costs of $7,938/person. The changes resulted in an increase of up to 26 LYG/1,000 individuals and a decrease in total screening and treatment costs by as much as $128/person. Follow-up colonoscopy at $0 coinsurance became cost-saving with any increase in either overall screening or follow-up colonoscopy. Policies that remove cost barriers to completing colorectal cancer screening may increase rates of screening participation, potentially improving economic and clinical outcomes.

SIGNIFICANCE

A follow-up colonoscopy after a positive stool-based colorectal cancer screening test is necessary to complete the full screening process. Policies that remove cost barriers to completing colorectal cancer screening may lead to increases in overall participation rates and use of follow-up colonoscopy, improving clinical and economic outcomes.

Comparison of Simulated Outcomes Between Stool- and Blood-Based Colorectal Cancer Screening Tests

The Centers for Medicare & Medicaid Services (CMS) recommend covering blood-based tests meeting proposed minimum performance thresholds for colorectal cancer (CRC) screening. Outcomes were compared between currently available stool-based screening tests and a hypothetical blood-based test meeting CMS minimum thresholds. Using the Colorectal Cancer and Adenoma Incidence and Mortality Microsimulation Model (CRC-AIM), outcomes were simulated for average-risk individuals screened between ages 45 and 75 years with triennial multitarget stool DNA (mt-sDNA), annual fecal immunochemical test (FIT), and annual fecal occult blood test (FOBT). Per CMS guidance, blood-based CRC screening was modeled triennially, with 74% CRC sensitivity and 90% specificity. Although not specified by CMS, adenoma sensitivity was set between 10% and 20%. Published adenoma and CRC sensitivity and specificity were used for stool-based tests. Adherence was set at (1) 100%, (2) 30%-70%, in 10% increments, and (3) real-world rates for stool-based tests (mt-sDNA = 65.6%; FIT = 42.6%; FOBT = 34.4%). Assuming perfect adherence, a blood-based test produced ≥19 lower life-years gained (LYG) than stool-based strategies. At the best-case scenario for blood-based tests (100% adherence and 20% adenoma sensitivity), mt-sDNA at real-world adherence achieved more LYG (287.2 vs. 297.1, respectively) with 14% fewer colonoscopies. At 100% blood-based test adherence and real-world mt-sDNA and FIT adherence, the blood-based test would require advanced adenoma sensitivity of 30% to reach the LYG of mt-sDNA (297.1) and ∼15% sensitivity to reach the LYG of FIT (258.9). This model suggests that blood-based tests with CMS minimally acceptable CRC sensitivity and low advanced adenoma sensitivity will frequently yield inferior outcomes to stool-based testing across a wide range of adherence assumptions.

Calibration and Validation of the Colorectal Cancer and Adenoma Incidence and Mortality (CRC-AIM) Microsimulation Model Using Deep Neural Networks

OBJECTIVES

Machine learning (ML)-based emulators improve the calibration of decision-analytical models, but their performance in complex microsimulation models is yet to be determined.

METHODS

We demonstrated the use of an ML-based emulator with the Colorectal Cancer (CRC)-Adenoma Incidence and Mortality (CRC-AIM) model, which includes 23 unknown natural history input parameters to replicate the CRC epidemiology in the United States. We first generated 15,000 input combinations and ran the CRC-AIM model to evaluate CRC incidence, adenoma size distribution, and the percentage of small adenoma detected by colonoscopy. We then used this data set to train several ML algorithms, including deep neural network (DNN), random forest, and several gradient boosting variants (i.e., XGBoost, LightGBM, CatBoost) and compared their performance. We evaluated 10 million potential input combinations using the selected emulator and examined input combinations that best estimated observed calibration targets. Furthermore, we cross-validated outcomes generated by the CRC-AIM model with those made by CISNET models. The calibrated CRC-AIM model was externally validated using the United Kingdom Flexible Sigmoidoscopy Screening Trial (UKFSST).

RESULTS

The DNN with proper preprocessing outperformed other tested ML algorithms and successfully predicted all 8 outcomes for different input combinations. It took 473 s for the trained DNN to predict outcomes for 10 million inputs, which would have required 190 CPU-years without our DNN. The overall calibration process took 104 CPU-days, which included building the data set, training, selecting, and hyperparameter tuning of the ML algorithms. While 7 input combinations had acceptable fit to the targets, a combination that best fits all outcomes was selected as the best vector. Almost all of the predictions made by the best vector laid within those from the CISNET models, demonstrating CRC-AIM's cross-model validity. Similarly, CRC-AIM accurately predicted the hazard ratios of CRC incidence and mortality as reported by UKFSST, demonstrating its external validity. Examination of the impact of calibration targets suggested that the selection of the calibration target had a substantial impact on model outcomes in terms of life-year gains with screening.

CONCLUSIONS

Emulators such as a DNN that is meticulously selected and trained can substantially reduce the computational burden of calibrating complex microsimulation models.

HIGHLIGHTS

Calibrating a microsimulation model, a process to find unobservable parameters so that the model fits observed data, is computationally complex.We used a deep neural network model, a popular machine learning algorithm, to calibrate the Colorectal Cancer Adenoma Incidence and Mortality (CRC-AIM) model.We demonstrated that our approach provides an efficient and accurate method to significantly speed up calibration in microsimulation models.The calibration process successfully provided cross-model validation of CRC-AIM against 3 established CISNET models and also externally validated against a randomized controlled trial.

The cost-effectiveness of non-invasive stool-based colorectal cancer screening offerings from age 45 for a commercial and medicare population

AIM

The United States Preventive Services Taskforce (USPSTF) recently recommended lowering the age for average-risk colorectal cancer (CRC) screening from 50 to 45 years. While initiating screening at age 45 versus 50 provides a greater opportunity for CRC early detection and prevention, the full profile of benefits, risks, and cost-effectiveness of expanding the screen-eligible population requires further evaluation.

MATERIALS AND METHODS

The costs and clinical outcomes for screening at age 45 for triennial multi-target stool DNA [mt-sDNA], and other non-invasive stool-based modalities (annual fecal immunochemical test [FIT] and annual fecal-occult blood test [FOBT]), were estimated using the validated CRC-AIM microsimulation model over a lifetime horizon. Test sensitivity and specificity inputs were based on 2021 USPSTF modeling analyses; adherence rates were based on published real-world data and the costs of the screening test, follow-up colonoscopies, complications, and CRC care were included. Outcomes are reported from the perspective of a United States payer as clinical, life-years gained (LYG), and incremental cost-effectiveness ratio (ICER); stool-based and follow-up colonoscopy adherence ranges were explored in one-way, probabilistic and threshold analyses.

RESULTS

When compared to initiation of CRC screening at age 45 versus 50, all modalities reduced both the incidence of and mortality from CRC and increased LYG. Initiating CRC screening at age 45 was cost-effective with an ICER of $59,816 and $35,857 per quality-adjusted life year (QALY) for mt-sDNA versus FIT and FOBT, respectively. In the threshold analyses, at equivalent rates to stool-based screening, mt-sDNA was always cost-effective at a willingness-to-pay threshold of $100,000 per QALY versus FIT and FOBT.

CONCLUSIONS

Initiating average-risk CRC screening at age 45 instead of age 50 increases the estimated clinical benefit by reducing disease burden while remaining cost-effective. Among stool-based screening modalities, mt-sDNA provides the most clinical benefit in a Commercial and Medicare population.

Cost-Effectiveness of Waiving Coinsurance for Follow-Up Colonoscopy after a Positive Stool-Based Colorectal Screening Test in a Medicare Population

Commercial insurance covers a follow-up colonoscopy after a positive colorectal cancer-screening test with no patient cost-sharing. Instituting a similar policy for Medicare beneficiaries may increase screening adherence and improve outcomes. The cost-effectiveness of stool-based colorectal cancer screening was compared across adherence scenarios that assumed Medicare coinsurance status quo (20% for follow-up colonoscopy) or waived coinsurance. The CRC-AIM model simulated previously unscreened eligible Medicare beneficiaries undergoing stool-based colorectal cancer screening at age 65 for 10 years. Medicare costs, colorectal cancer cases, colorectal cancer-related deaths, life-years gained (LYG), and quality-adjusted life-years (QALY) were estimated versus no screening. Scenario 1 (S1) assumed 20% coinsurance for follow-up colonoscopy. Scenario 2 (S2) assumed waived coinsurance without adherence changes. Scenarios 3-7 (S3-S7) assumed that waiving coinsurance increased real-world stool-based screening and/or follow-up colonoscopy adherence by 5% or 10%. Sensitivity analyses assumed 1%-4% increased adherence. Cost-effectiveness threshold was ≤$100,000/QALY. Waiving coinsurance without adherence changes (S2) did not affect outcomes versus S1. S3-S7 versus S1 over 10 years estimated up to 3.6 fewer colorectal cancer cases/1,000 individuals, up to 2.1 fewer colorectal cancer deaths, up to 20.7 more LYG, and had comparable total costs per-patient (≤$6,478 vs. $6,449, respectively) as reduced colorectal cancer medical costs offset increased screening and colonoscopy costs. In sensitivity analyses, any increase in adherence after waiving coinsurance was cost-effective and increased LYG. In simulated Medicare beneficiaries, waiving coinsurance for follow-up colonoscopy after a positive stool-based test improved outcomes and was cost-effective when assumed to modestly increase colorectal cancer screening and/or follow-up colonoscopy adherence.

PREVENTION RELEVANCE

Follow-up colonoscopy after a positive stool-based test is necessary to complete the colorectal cancer-screening process. This analysis demonstrated that in a simulated Medicare population, waiving coinsurance for a follow-up colonoscopy improved estimated outcomes and was cost-effective when it was assumed that waiving the coinsurance modestly increased screening adherence. See related Spotlight, p. 641.

Modeling analysis of COVID 19-related delays in colorectal cancer screening on simulated clinical outcomes

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Background: Colorectal cancer (CRC) screening disruptions have been observed with the COVID-19 pandemic, putting patients at risk for more advanced-stage disease at the time of diagnosis. We estimated the impact of increased use of stool-based tests for screening during the COVID-19 pandemic on near-term clinical outcomes in a simulated United States (US) population. Methods: A previously developed budget impact model was adapted to assess the impact of increasing use of multi-target stool DNA [mt-sDNA] or fecal immunochemical [FIT] tests to offset the COVID-19 related disruption in colonoscopy screening. Adults, ages 50 – 75 years, at average risk for CRC were included over a 3-year time horizon (2020 – 2023) to explore the impact of increased screening for CRC using mt-sDNA or FIT, from the perspective of a US payer. Compared to the base case (S0; 85% colonoscopy and 15% non-invasive tests), the estimated number of missed CRCs and advanced adenomas (AAs) were determined for four COVID-19-affected screening scenarios: S1, 9 months of CRC screening at 50% capacity, followed by 21 months at 75% capacity; S2, S1 followed by increasing stool-based testing by an average of 10% over 3-years; S3, 18 months of CRC screening at 50% capacity, followed by 12 months of 75% capacity; and S4, S3 followed by increasing stool-based testing by an average of 13% over 3-years. Results: Increasing the proportional use of mt-sDNA, the detection of AAs improved by 6.0% (Scenario 2 versus 1) to 8.4% (Scenario 4 versus 3) and the number of missed CRCs decreased by 15.1% to 17.3% respectively. Increasing FIT utilization improved the detection of AAs by 3.3% (Scenario 2 versus 1) to 4.6% (Scenario 4 versus 3) and the number of missed CRCs decreased by 12.9% (Scenario 2 versus 1) to 14.9% (Scenario 4 versus 3). Across all scenarios, the number of AAs detected was higher for mt-sDNA than for FIT, and the number of missed CRCs was lower for mt-sDNA than for FIT. Conclusions: Using home-based stool tests for average-risk CRC screening can mitigate the consequences of reduced colonoscopy screening resulting from the COVID-19 pandemic. Use of mt-sDNA led to fewer missed CRCs and more AAs detected, compared to FIT.

Cost-effectiveness of mt-sDNA versus mailed FIT outreach for Medicare Advantage enrollees using the CRC-AIM microsimulation model

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Background: Despite proven effectiveness in reducing colorectal cancer (CRC) cases, screening for CRC remains underutilized, including those enrolled in Medicare Advantage. A mailed fecal immunochemical test (FIT) outreach program may increase CRC screening adherence. This study examined the cost-effectiveness of stool-based tests (FIT and multi-target stool DNA [mt-sDNA]), with FIT offered via a mailed outreach program, in a Medicare Advantage population. Methods: The validated CRC-AIM microsimulation model was used to simulate the costs and clinical outcomes of 2 million average-risk individuals, free of diagnosed CRC at age 40, who initiated CRC screening at age 65. Annual mailed FIT outreach and triennial mt-sDNA were assessed. Test sensitivity and specificity inputs were based on the 2021 United States Preventative Services Task Force modeling study. FIT outreach program cost ($25.92) and direct costs for screening tests, colonoscopies (COLs), complications, and CRC care were included. The model employed a lifetime horizon, 3% discount rates, and a Medicare Advantage perspective. The primary analysis used published real-world adherence rates for stool-based tests and follow-up COLs (FIT/COL: 29%/53%; mt-sDNA/COL: 69.8%/71.5%). Secondary analyses assumed 100% adherence for stool-based tests and/or follow-up COLs and 20% higher than primary analysis for FIT and the corresponding follow-up COLs. Results: In the primary analysis, mt-sDNA had the greatest life-years gained (LYG), incidence reduction (IR), and mortality reduction (MR) and was cost-effective at a willingness-to-pay threshold of $50,000/QALY compared to mailed FIT outreach (Table). This was true when 100% adherence was assumed for follow-up COL and when FIT had 20% higher adherence than the primary analysis. mt-sDNA had 64-129% greater LYG, 79-150% greater IR, and 68-146% greater MR than mailed FIT outreach. When assuming 100% adherence for both screening test and follow-up COL, mt-sDNA was dominated by mailed FIT outreach. Conclusions: Adherence to CRC screening modality and follow-up COL greatly impacts clinical and cost-effectiveness outcomes. Future analysis should consider evidence-based, health plan-specific data to accurately reflect outcomes that aid in payer decision making.[Table: see text]

Comparison of simulated outcomes between stool- and blood-based colorectal cancer screening tests

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Background: The Centers for Medicare & Medicaid Services (CMS) recommends covering blood-based biomarker tests with proposed minimum performance thresholds for colorectal cancer (CRC) screening test every 3 years for average-risk, asymptomatic Medicare beneficiaries ages 50–85 years. A blood-based test is a non-invasive screening method to detect CRC but is limited by low sensitivity to detect adenomas. Using the CRC-AIM microsimulation model, predicted life-years gained (LYG) and CRC incidence and mortality reduction were compared between a blood-based test meeting the CMS minimum thresholds and stool-based screening tests (fecal immunochemical test [FIT], fecal occult blood test [FOBT], and multitarget stool DNA [mt-sDNA]). Methods: Outcomes of blood- and stool-based tests were simulated for average-risk individuals free of diagnosed CRC at age 40 and screened between ages 45–75 years per USPSTF recommendations. Per CMS proposed criteria, CRC sensitivity and specificity for a blood-based test were set at 74% and 90%, respectively, and adenoma sensitivity was set at 10%. Published adenoma and CRC sensitivity and specificity were used for each stool test. For the primary analysis, adherence was assumed to be 100%. For secondary analysis, adherence was set at 30–70%, in 10% increments. Outcomes were per 1000 individuals. Results: At 100% adherence, LYG was 229 for a blood test and ≥305 for stool tests, corresponding to at least 25% lower LYG for a blood test relative to all stool tests (Table). Absolute CRC incidence and mortality reductions were at least 19% and 18% lower, respectively, for a blood test vs all stool tests. Secondary analysis indicates that at identical adherence rates that are less than 100%, a blood test had lower LYG vs all stool tests (Table). When the adherence of any test was 50%–70%, a blood test resulted in at least 20% lower LYG vs any stool test, and absolute reductions in CRC incidence and mortality were at least 9% and 10% lower, respectively, vs any stool test. Conclusions: This model suggests that if blood-based CRC screening tests do not sufficiently detect advanced adenomas, clinical outcomes will be inferior to stool-based testing due to lack of cancer prevention. Further discovery efforts to identify blood-based markers associated with both invasive and preinvasive neoplasia are needed to address this deficiency. [Table: see text]

Cost-effectiveness of waiving coinsurance for follow-up colonoscopy after a positive stool-based colorectal screening test in a Medicare population

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Background: Commercial insurance plans are required to cover, with no patient cost sharing, a follow-up colonoscopy (COL) after a positive stool-based colorectal cancer (CRC) screening test. Medicare beneficiaries may still be responsible for 20% coinsurance for a follow-up COL, posing a financial barrier to screening completion. Removing the coinsurance may increase screening adherence and improve outcomes. The estimated cost-effectiveness of stool-based CRC screening was compared among adherence scenarios that assumed the status quo (20% coinsurance for follow-up COL) or waived follow-up COL coinsurance. Methods: The CRC-AIM microsimulation model simulated US Medicare beneficiaries undergoing stool-based CRC screening between ages 65-75 years. Outcomes of total costs, total quality adjusted life years (QALYs), life-years gained (LYG), CRC incidence reductions (IR), and CRC mortality reductions (MR) were calculated per 1000 individuals versus no screening using the weighted average of the outcome with multitarget stool DNA, fecal immunochemical test, and fecal occult blood test, scaled by their estimated use. Costs of follow-up COL were assumed to have 20% coinsurance in the status quo scenario. Four comparative scenarios assumed that waiving coinsurance increased published, real-world stool-based screening or follow-up COL adherence rates by 5% or 10%. Results: In scenarios where waiving coinsurance was assumed to increase screening and/or follow-up COL adherence, up to 21 more LYG and greater IR and MR were observed vs the status quo (Table). Total costs in waived coinsurance scenarios (≥$6,398) were comparable to the status quo ($6,449) as the cost savings in CRC care offset the increased COL costs. Total QALYs in waived coinsurance scenarios (≥9.3671) were greater than the status quo (9.3643) because of improved clinical outcomes. Stool-based testing in waived coinsurance scenarios was either dominant (more effective and less costly) or cost-effective at $50,000/QALY with minimal incremental costs vs the status quo. Conclusions: In a simulated Medicare population, clinical CRC outcomes improved and stool-based screening was cost-effective or cost-saving when waiving the 20% coinsurance was assumed to modestly (5%) increase adherence rates for total CRC screening and/or a COL following a positive test. [Table: see text]

Trends in Thyroid Surgery and Guideline-Concordant Care in the United States, 2007-2018

Background: The American Thyroid Association (ATA) published the 2015 Management Guidelines for patients with thyroid nodules and differentiated thyroid cancer, recommending a shift to less aggressive diagnostic, surgical, and postoperative treatment strategies. At the same time and perhaps related to the new guidelines, there has been a shift to outpatient thyroid surgery. The aim of the current study was to assess physician adherence to these recommendations by identifying and quantifying temporal trends in the rates and indications for thyroid procedures in the inpatient and outpatient settings. Methods: Using the IBM^® MarketScan^® Commercial database, we identified employer-insured patients in the United States who underwent outpatient and inpatient thyroid surgery from 2007 to 2018. Thyroid surgery was classified as total thyroidectomy (TT), thyroid lobectomy (TL), or a completion thyroidectomy. The surgical indication diagnosis was also determined and classified as either benign or malignant thyroid disease. We compared outpatient and inpatient trends in surgery between benign and malignant thyroid disease both before and after the release of the 2015 ATA guidelines. Results: A total of 220,088 patients who underwent thyroid surgery were included in the analysis. Approximately 80% of TLs were performed in the outpatient setting versus 70% of TTs. Longitudinal analysis showed a statistically significant changepoint for TT proportion occurring in November 2015. The proportion of TT as compared with TL decreased from 80% in September 2015 to 39% by December 2018. For thyroid cancer, there is an increasing trend in performing TL over TT, increasing from 17% in 2015 to 28% by the end of 2018. Conclusions: There was a significant changepoint occurring in November 2015 in the operative and management trends for benign and malignant thyroid disease.

Patient and Provider Risk in Managing ST-Elevation Myocardial Infarction During the COVID-19 Pandemic: A Decision Analysis

BACKGROUND

The optimal treatment strategy for treating ST-segment-elevation myocardial infarction (STEMI) in context of the coronavirus disease 2019 (COVID-19) pandemic is unclear given the potential risk of occupational exposure during primary percutaneous coronary intervention (PPCI). We quantified the impact of different STEMI treatment strategies on patient outcomes and provider risk in context of the COVID-19 pandemic.

METHODS

Using a decision-analytic framework, we evaluated the effect of PPCI versus the pharmaco-invasive strategy for managing STEMI on 30-day patient mortality and individual provider infection risk based on presence of cardiogenic shock, suspected coronary territory, and presence of known or presumptive COVID-19 infection.

RESULTS

For patients with low suspicion for COVID-19, PPCI had mortality benefit over the pharmaco-invasive strategy, and the risk of cardiac catheterization laboratory provider infection remained very low (<0.25%) across all subgroups. For patients with presumptive COVID-19 with cardiogenic shock, PPCI offered substantial mortality benefit to patients relative to the pharmaco-invasive strategy (7.9% absolute decrease in 30-day mortality), but also greater risk of provider infection (2.3% absolute increase in risk of provider infection). For patients with presumptive COVID-19 with nonanterior STEMI without cardiogenic shock, PPCI offered a 0.4% absolute mortality benefit over the pharmaco-invasive strategy with a 0.2% greater absolute risk of provider infection, and the tradeoff between patient and provider risk with PPCI became more apparent in sensitivity analysis with more severe COVID-19 infections.

CONCLUSIONS

Usual care with PPCI remains the appropriate treatment strategy in the majority of cases presenting with STEMI in the setting of the COVID-19 pandemic. However, utilization of a pharmaco-invasive strategy in selected patients with STEMI with presumptive COVID-19 and low likelihood of mortality from STEMI and use of preventive strategies such as preprocedural intubation in high risk patients when PPCI is the preferred strategy may be reasonable to reduce provider risk of COVID-19 infection.

Improving patient timeliness of care through efficient outpatient clinic layout design using data-driven simulation and optimisation

With greater demand for outpatient services, the importance of patient-centric clinic layout design that improves timeliness of patient care has become more elucidated. In this paper, a novel simulation-optimisation (SO) framework is proposed focusing on the physical and process flows of patients in the design of a paediatric orthopaedic outpatient clinic. A discrete-event simulation model is used to estimate the frequency of movements between clinic units. The resulting information is utilised as input to a mixed integer programming (MIP) model, optimising the clinic layout design. In order to solve the MIP model, Particle Swarm Optimisation (PSO), a metaheuristic approach enhanced with several heuristics is utilised. Finally, the optimisation model outputs are evaluated with the simulation model. The results demonstrate that improvements to the quality of the patient experience can be achieved through incorporating SO methods into the clinic layout design process.

Adoption of New Medical Technologies: The Case of Customized Individually Made Knee Implants

OBJECTIVES

To investigate the impact of insurance coverage on the adoption of customized individually made (CIM) knee implants and to compare patient outcomes and cost effectiveness of off-the-shelf and CIM implants.

METHODS

A system dynamics simulation model was developed to study adoption dynamics of CIM and meet the research objectives. The model reproduced the historical data on primary and revision knee replacement implants obtained from the literature and the Nationwide Inpatient Sample. Then the dynamics of adoption of CIM implants were simulated from 2018 to 2026. The rate of 90-day readmission, 3-year revision surgery, recovery period, time savings in operating rooms, and the associated cost within 3 years of primary knee replacement implants were used as performance metrics.

RESULTS

The simulation results indicate that by 2026, an adoption rate of 90% for CIM implants can reduce the number of readmissions and revision surgeries by 62% and 39%, respectively, and can save hospitals and surgeons 6% on procedure time and cut down cumulative healthcare costs by approximately $38 billion.

CONCLUSIONS

CIM implants have the potential to deliver high-quality care while decreasing overall healthcare costs, but their adoption requires the expansion of current insurance coverage. This work presents the first systematic study to understand the dynamics of adoption of CIM knee implants and instrumentation. More broadly, the current modeling approach and systems thinking perspective could be used to consider the adoption of any emerging customized therapies for personalized medicine.

Analysis of the effects of EHR implementation on timeliness of care in a dermatology clinic: a simulation study

Objective

Quantify the downstream impact on patient wait times and overall length of stay due to small increases in encounter times caused by the implementation of a new electronic health record (EHR) system.

Methods

A discrete-event simulation model was created to examine the effects of increasing the provider-patient encounter time by 1, 2, 5, or 10 min, due to an increase in in-room documentation as part of an EHR implementation. Simulation parameters were constructed from an analysis of 52 000 visits from a scheduling database and direct observation of 93 randomly selected patients to collect all the steps involved in an outpatient dermatology patient care visit.

Results

Analysis of the simulation results demonstrates that for a clinic session with an average booking appointment length of 15 min, the addition of 1, 2, 5, and 10 min for in-room physician documentation with an EHR system would result in a 5.2 (22%), 9.8 (41%), 31.8 (136%), and 87.2 (373%) minute increase in average patient wait time, and a 6.2 (12%), 11.7 (23%), 36.7 (73%), and 96.9 (193%) minute increase in length of stay, respectively. To offset the additional 1, 2, 5, or 10 min, patient volume would need to decrease by 10%, 20%, 40%, and >50%, respectively.

Conclusions

Small changes to processes, such as the addition of a few minutes of extra documentation time in the exam room, can cause significant delays in the timeliness of patient care. Simulation models can assist in quantifying the downstream effects and help analyze the impact of these operational changes.

Decreasing patient length of stay via new flexible exam room allocation policies in ambulatory care clinics

To address prolonged lengths of stay (LOS) in ambulatory care clinics, we analyze the impact of implementing flexible and dynamic policies for assigning exam rooms to providers. In contrast to the traditional approaches of assigning specific rooms to each provider or pooling rooms among all practitioners, we characterize the impact of alternate compromise policies that have not been explored in previous studies. Since ambulatory care patients may encounter multiple different providers in a single visit, room allocation can be determined separately for each encounter accordingly. For the first phase of the visit, conducted by the medical assistant, we define a dynamic room allocation policy that adjusts room assignments based on the current state of the clinic. For the second phase of the visit, conducted by physicians, we define a series of room sharing policies which vary based on two dimensions, the number of shared rooms and the number of physicians sharing each room. Using a discrete event simulation model of an outpatient cardiovascular clinic, we analyze the benefits and costs associated with the proposed room allocation policies. Our findings show that it is not necessary to fully share rooms among providers in order to reduce patient LOS and physician idle time. Instead, most of the benefit of pooling can be achieved by implementation of a compromise room allocation approach, limiting the need for significant organizational changes within the clinic. Also, in order to achieve most of the benefits of room allocation policies, it is necessary to increase flexibility in the two dimensions simultaneously. These findings are shown to be consistent in settings with alternate patient scheduling and distinctions between physicians.

Quantitative assessment of emphysema using hyperpolarized 3He magnetic resonance imaging

In this experiment, Sprague-Dawley rats with elastase-induced emphysema were imaged using hyperpolarized (3)He MRI. Regional fractional ventilation r, the fraction of gas replaced with a single tidal breath, was calculated from a series of images in a wash-in study of hyperpolarized gas. We compared the regional fractional ventilation in these emphysematous rats to the regional fractional ventilations we calculated from a previous baseline study in healthy Sprague-Dawley rats. We found that there were differences in the maps of fractional ventilation and its associated frequency distribution between the healthy and emphysematous rat lungs. Fractional ventilation tended to be much lower in emphysematous rats than in normal rats. With this information, we can use data on fractional ventilation to regionally distinguish between healthy and emphysematous portions of the lung. The successful implementation of such a technique on a rat model could lead to work toward the future implementation of this technique in human patients.