Kinesin-14 motors participate in a force balance at microtubule plus-ends to regulate dynamic instability.

Kinesin-14 molecular motors represent an essential class of proteins that bind microtubules and walk toward their minus-ends. Previous studies have described important roles for Kinesin-14 motors at microtubule minus-ends, but their role in regulating plus-end dynamics remains controversial. Kinesin-14 motors have been shown to bind the EB family of microtubule plus-end binding proteins, suggesting that these minus-end-directed motors could interact with growing microtubule plus-ends. In this work, we explored the role of minus-end-directed Kinesin-14 motor forces in controlling plus-end microtubule dynamics. In cells, a Kinesin-14 mutant with reduced affinity to EB proteins led to increased microtubule lengths. Cell-free biophysical microscopy assays were performed using Kinesin-14 motors and an EB family marker of growing microtubule plus-ends, Mal3, which revealed that when Kinesin-14 motors bound to Mal3 at growing microtubule plus-ends, the motors subsequently walked toward the minus-end, and Mal3 was pulled away from the growing microtubule tip. Strikingly, these interactions resulted in an approximately twofold decrease in the expected postinteraction microtubule lifetime. Furthermore, generic minus-end-directed tension forces, generated by tethering growing plus-ends to the coverslip using λ-DNA, led to an approximately sevenfold decrease in the expected postinteraction microtubule growth length. In contrast, the inhibition of Kinesin-14 minus-end-directed motility led to extended tip interactions and to an increase in the expected postinteraction microtubule lifetime, indicating that plus-ends were stabilized by nonmotile Kinesin-14 motors. Together, we find that Kinesin-14 motors participate in a force balance at microtubule plus-ends to regulate microtubule lengths in cells.

Food Is Medicine: A Presidential Advisory From the American Heart Association.

Unhealthy diets are a major impediment to achieving a healthier population in the United States. Although there is a relatively clear sense of what constitutes a healthy diet, most of the US population does not eat healthy food at rates consistent with the recommended clinical guidelines. An abundance of barriers, including food and nutrition insecurity, how food is marketed and advertised, access to and affordability of healthy foods, and behavioral challenges such as a focus on immediate versus delayed gratification, stand in the way of healthier dietary patterns for many Americans. Food Is Medicine may be defined as the provision of healthy food resources to prevent, manage, or treat specific clinical conditions in coordination with the health care sector. Although the field has promise, relatively few studies have been conducted with designs that provide strong evidence of associations between Food Is Medicine interventions and health outcomes or health costs. Much work needs to be done to create a stronger body of evidence that convincingly demonstrates the effectiveness and cost-effectiveness of different types of Food Is Medicine interventions. An estimated 90% of the $4.3 trillion annual cost of health care in the United States is spent on medical care for chronic disease. For many of these diseases, diet is a major risk factor, so even modest improvements in diet could have a significant impact. This presidential advisory offers an overview of the state of the field of Food Is Medicine and a road map for a new research initiative that strategically approaches the outstanding questions in the field while prioritizing a human-centered design approach to achieve high rates of patient engagement and sustained behavior change. This will ideally happen in the context of broader efforts to use a health equity-centered approach to enhance the ways in which our food system and related policies support improvements in health.

State variation in effects of state social distancing policies on COVID-19 cases.

BACKGROUND: The novel coronavirus disease 2019 (COVID-19) sickened over 20 million residents in the United States (US) by January 2021. Our objective was to describe state variation in the effect of initial social distancing policies and non-essential business (NEB) closure on infection rates early in 2020. METHODS: We used an interrupted time series study design to estimate the total effect of all state social distancing orders, including NEB closure, shelter-in-place, and stay-at-home orders, on cumulative COVID-19 cases for each state. Data included the daily number of COVID-19 cases and deaths for all 50 states and Washington, DC from the New York Times database (January 21 to May 7, 2020). We predicted cumulative daily cases and deaths using a generalized linear model with a negative binomial distribution and a log link for two models. RESULTS: Social distancing was associated with a 15.4% daily reduction (Relative Risk = 0.846; Confidence Interval [CI] = 0.832, 0.859) in COVID-19 cases. After 3 weeks, social distancing prevented nearly 33 million cases nationwide, with about half (16.5 million) of those prevented cases among residents of the Mid-Atlantic census division (New York, New Jersey, Pennsylvania). Eleven states prevented more than 10,000 cases per 100,000 residents within 3 weeks. CONCLUSIONS: The effect of social distancing on the infection rate of COVID-19 in the US varied substantially across states, and effects were largest in states with highest community spread.

Association of ACO Shared Savings Success and Serious Illness Spending.

EXECUTIVE SUMMARY: Accountable care organizations (ACOs) need confidence in their return on investment to implement changes in care delivery that prioritize seriously ill and high-cost Medicare beneficiaries. The objective of this study was to characterize spending on seriously ill beneficiaries in ACOs with Medicare Shared Savings Program (MSSP) contracts and the association of spending with ACO shared savings. The population included Medicare fee-for-service beneficiaries identified with serious illness (N = 2,109,573) using the Medicare Master Beneficiary Summary File for 100% of ACO-attributed beneficiaries linked to MSSP beneficiary files (2014-2016). Lower spending for seriously ill Medicare beneficiaries and risk-bearing contracts in ACOs were associated with achieving ACO shared savings in the MSSP. For most ACOs, the seriously ill contribute approximately half of the spending and constitute 8%-13% of the attributed population. Patient and geographic (county) factors explained $2,329 of the observed difference in per beneficiary per year spending on seriously ill beneficiaries between high- and low-spending ACOs. The remaining $12,536 may indicate variation as a result of potentially modifiable factors. Consequently, if 10% of attributed beneficiaries were seriously ill, an ACO that moved from the worst to the best quartile of per capita serious illness spending could realize a reduction of $1,200 per beneficiary per year for the ACO population overall. Though the prevalence and case mix of seriously ill populations vary across ACOs, this association suggests that care provided for seriously ill patients is an important consideration for ACOs to achieve MSSP shared savings.

Call to Action: Urgent Challenges in Cardiovascular Disease: A Presidential Advisory From the American Heart Association.

Although advances in care have spurred improvements in cardiovascular outcomes, cardiovascular disease remains the leading cause of death in the United States and around the world. Previous declines in cardiovascular disease mortality have slowed and even reversed for certain demographics. Further concerns exist with regard to cardiovascular drug innovation, quality of care, and healthcare costs. The Value in Healthcare Initiative-Transforming Cardiovascular Care, a collaboration of the American Heart Association and Duke University, Robert J. Margolis, MD, Center for Health Policy, aims to increase access to and affordability of cardiovascular treatment and to decrease barriers to care. The following Call to Action describes trends in cardiovascular care, identifies gaps in areas of cardiovascular disease prevention and treatment, highlights challenges with medical product innovation, and finally, outlines a series of learning collaboratives that will aid in the development of road maps for transforming cardiovascular care.

The Affordable Care Act: What's Next?

The postelection efforts to repeal, replace, or modify the Affordable Care Act (ACA) suggest that the debate over healthcare coverage will remain contentious, particularly because of the high and rising cost of health care. Feasible, potentially bipartisan approaches to improving access to coverage should emphasize reforming health care to achieve higher quality at a lower cost. In the individual market, where many enrollees face limited options and rising premiums, a combination of high-risk pools, reinsurance, and risk adjustment could improve coverage options while encouraging innovations in care for the highest-risk patients. State Medicaid programs, which are increasingly important sources of coverage but are crowding out other important budget priorities that affect population health, could achieve better results through federal reforms that provide more flexibility for states alongside greater emphasis on achieving better outcomes. Accelerating payment reforms and other policy changes to encourage more innovative and efficient care delivery models, along with developing better evidence on successful models, can also improve the prospects for coverage reform.

A Roadmap for Value-Based Payment Models Among Patients With Cirrhosis.

Healthcare reimbursement is shifting from fee-for-service to fee-for-value. Cirrhosis, which costs the U.S. healthcare system as much as heart failure, is a prime target for value-based care. This article describes models in which physician groups or health systems are paid for improving quality and lowering costs for a given population of patients with cirrhosis. If done correctly, we believe that such frameworks, once adopted, could help reduce burnout by freeing physicians of the burden of checking boxes in the electronic medical record so that they can devote their energies to managing populations. Conclusion: Value-based payment models for cirrhosis have the potential to benefit patients, physicians, and healthcare insurers.

Comparing Associations of State Reopening Strategies with COVID-19 Burden.

BACKGROUND: The novel coronavirus disease 2019 (COVID-19) infected over 5 million United States (US) residents resulting in more than 180,000 deaths by August 2020. To mitigate transmission, most states ordered shelter-in-place orders in March and reopening strategies varied. OBJECTIVE: To estimate excess COVID-19 cases and deaths after reopening compared with trends prior to reopening for two groups of states: (1) states with an evidence-based reopening strategy, defined as reopening indoor dining after implementing a statewide mask mandate, and (2) states reopening indoor dining rooms before implementing a statewide mask mandate. DESIGN: Interrupted time series quasi-experimental study design applied to publicly available secondary data. PARTICIPANTS: Fifty United States and the District of Columbia. INTERVENTIONS: Reopening indoor dining rooms before or after implementing a statewide mask mandate. MAIN MEASURES: Outcomes included daily cumulative COVID-19 cases and deaths for each state. KEY RESULTS: On average, the number of excess cases per 100,000 residents in states reopening without masks is ten times the number in states reopening with masks after 8 weeks (643.1 cases; 95% confidence interval (CI) = 406.9, 879.2 and 62.9 cases; CI = 12.6, 113.1, respectively). Excess cases after 6 weeks could have been reduced by 90% from 576,371 to 63,062 and excess deaths reduced by 80% from 22,851 to 4858 had states implemented mask mandates prior to reopening. Over 50,000 excess deaths were prevented within 6 weeks in 13 states that implemented mask mandates prior to reopening. CONCLUSIONS: Additional mitigation measures such as mask use counteract the potential growth in COVID-19 cases and deaths due to reopening businesses. This study contributes to the growing evidence that mask usage is essential for mitigating community transmission of COVID-19. States should delay further reopening until mask mandates are fully implemented, and enforcement by local businesses will be critical for preventing potential future closures.

Correction to: Comparing Associations of State Reopening Strategies with COVID-19 Burden.

In the original version of this paper, an author was misidentified. The corrected author listing appears here, and has been updated in the online version.

The Past Decade of Paying for Value : From the Affordable Care Act to COVID-19.

The Affordable Care Act played a major role in transitioning American health care away from fee-for-service payment. We explore the spread of payment reforms since the implementation of the ACA, both nationally and in North Carolina; the corresponding effects on health care costs and quality; and further steps needed to achieve greater transformation.

North Carolina's Health Care Transformation to Value: Progress to Date and Further Steps Needed.

North Carolina has received national attention for its approach to health care payment and delivery reform. Importantly, payment reform alone is not enough to drive systematic changes in care delivery. We highlight the importance of progress in four complementary areas to achieve system-wide payment and care reform.

Payment Reform, Medication Use, and Costs: Can We Afford to Leave Out Drugs?

Medications are one of the fastest growing sources of costs in the health system and the cornerstone of disease management. Despite extensive attention around drug pricing, medications have largely been excluded from CMS-derived, value-based payment models. In this perspective, we synthesize evidence about the impact of three prominent models-primary care-based redesign, ACOs, and bundled payment programs-on medication use, adherence, and costs. We also examine the literature describing similar models implemented by private payors and their relationship with medication use and costs. The exclusion of drug costs from payment reform model design has led to missed opportunities for payors and providers to prioritize effective medication management strategies and has limited our learning about the effects on cost and quality. New CMS-based models are starting to allow greater flexibility in pharmacy benefit design and reward improved medication therapy management. Additionally, health plans, pharmacies, and pharmacy benefit managers are beginning to partner on collaborative value-based pharmacy initiatives. Taken together, these efforts encourage a paradigm shift around drug cost management that more deeply integrates pharmacy into payment and delivery reform with the goal of improving quality and reducing the total cost of care.

Mechanism of microtubule lumen entry for the α-tubulin acetyltransferase enzyme αTAT1.

Microtubules are structural polymers inside of cells that are subject to posttranslational modifications. These posttranslational modifications create functionally distinct subsets of microtubule networks in the cell, and acetylation is the only modification that takes place in the hollow lumen of the microtubule. Although it is known that the α-tubulin acetyltransferase (αTAT1) is the primary enzyme responsible for microtubule acetylation, the mechanism for how αTAT1 enters the microtubule lumen to access its acetylation sites is not well understood. By performing biochemical assays, fluorescence and electron microscopy experiments, and computational simulations, we found that αTAT1 enters the microtubule lumen through the microtubule ends, and through bends or breaks in the lattice. Thus, microtubule structure is an important determinant in the acetylation process. In addition, once αTAT1 enters the microtubule lumen, the mobility of αTAT1 within the lumen is controlled by the affinity of αTAT1 for its acetylation sites, due to the rapid rebinding of αTAT1 onto highly concentrated α-tubulin acetylation sites. These results have important implications for how acetylation could gradually accumulate on stable subsets of microtubules inside of the cell.

Payment and Care for Hematopoietic Cell Transplantation Patients: Toward a Specialized Medical Home for Complex Care Patients.

Patient-centered medical home models are fundamental to the advanced alternative payment models defined in the Medicare Access and Children's Health Insurance Plan Reauthorization Act (MACRA). The patient-centered medical home is a model of healthcare delivery supported by alternative payment mechanisms and designed to promote coordinated medical care that is simultaneously patient-centric and population-oriented. This transformative care model requires shifting reimbursement to include a per-patient payment intended to cover services not previously reimbursed such as disease management over time. Payment is linked to quality measures, including proportion of care delivered according to predefined pathways and demonstrated impact on outcomes. Some medical homes also include opportunities for shared savings by reducing overall costs of care. Recent proposals have suggested expanding the medical home model to specialized populations with complex needs because primary care teams may not have the facilities or the requisite expertise for their unique needs. An example of a successful care model that may provide valuable lessons for those creating specialty medical home models already exists in many hematopoietic cell transplantation (HCT) centers that deliver multidisciplinary, coordinated, and highly specialized care. The integration of care delivery in HCT centers has been driven by the specialty care their patients require and by the payment methodology preferred by the commercial payers, which has included bundling of both inpatient and outpatient care in the peritransplant interval. Commercial payers identify qualified HCT centers based on accreditation status and comparative performance, enabled in part by center-level comparative performance data available within a national outcomes database mandated by the Stem Cell Therapeutic and Research Act of 2005. Standardization across centers has been facilitated via voluntary accreditation implemented by Foundation for the Accreditation of Cell Therapy. Payers have built on these community-established programs and use public outcomes and program accreditation as standards necessary for inclusion in specialty care networks and contracts. Although HCT centers have not been described as medical homes, most HCT providers have already developed the structures that address critical requirements of MACRA for medical homes.

Suppression of microtubule assembly kinetics by the mitotic protein TPX2.

TPX2 is a widely conserved microtubule-associated protein that is required for mitotic spindle formation and function. Previous studies have demonstrated that TPX2 is required for the nucleation of microtubules around chromosomes; however, the molecular mechanism by which TPX2 promotes microtubule nucleation remains a mystery. In this study, we found that TPX2 acts to suppress tubulin subunit off-rates during microtubule assembly and disassembly, thus allowing for the support of unprecedentedly slow rates of plus-end microtubule growth, and also leading to a dramatically reduced microtubule shortening rate. These changes in microtubule dynamics can be explained in computational simulations by a moderate increase in tubulin-tubulin bond strength upon TPX2 association with the microtubule lattice, which in turn acts to reduce the departure rate of tubulin subunits from the microtubule ends. Thus, the direct suppression of tubulin subunit off-rates by TPX2 during microtubule growth and shortening could provide a molecular mechanism to explain the nucleation of new microtubules in the presence of TPX2.

Advancing Value Assessment in the United States: A Multistakeholder Perspective.

Rising costs without perceived proportional improvements in quality and outcomes have motivated fundamental shifts in health care delivery and payment to achieve better value. Aligned with these efforts, several value assessment frameworks have been introduced recently to help providers, patients, and payers better understand the potential value of drugs and other interventions and make informed decisions about their use. Given their early stage of development, it is imperative to evaluate these efforts on an ongoing basis to identify how best to support and improve them moving forward. This article provides a multistakeholder perspective on the key limitations and opportunities posed by the current value assessment frameworks and areas of and actions for improvement. In particular, we outline 10 fundamental guiding principles and associated strategies that should be considered in subsequent iterations of the existing frameworks or by emerging initiatives in the future. Although value assessment frameworks may not be able to meet all the needs and preferences of stakeholders, we contend that there are common elements and potential next steps that can be supported to advance value assessment in the United States.

Building a drug development database: challenges in reliable data availability.

CONTEXT: Policy and legislative efforts to improve the biomedical innovation process must rely on a detailed and thorough analysis of drug development and industry output. OBJECTIVE: As part of our efforts to build a publicly-available database on the characteristics of drug development, we present work undertaken to test methods for compiling data from public sources. These initial steps are designed to explore challenges in data extraction, completeness and reliability. Specifically, filing dates for Investigational New Drugs (IND) applications with the U.S. Food and Drug Administration (FDA) were chosen as the initial objective data element to be collected. MATERIALS AND METHODS: FDA's Drugs@FDA database and the Federal Register (FR) were used to collect IND dates for the 587 New Molecular Entities (NMEs) approved between 1994 and 2014. When available, the following data were captured: approval date, IND number, IND date and source of information. RESULTS: At least one IND date was available for 445 (75.8%) of the 587 NMEs. The Drugs@FDA database provided IND dates for 303 (51.6%) NMEs and the FR contributed with 297 (50.6%) IND dates. Out of the 445 NMEs for which an IND date was obtained, 274 (61.6%) had more than one date reported. DISCUSSION: Key finding of this paper is a considerable inconsistency in reliably available or reported data elements, in this particular case, IND application filing dates as assembled from publicly-available sources. CONCLUSION: Our team will continue to focus on finding ways to collect relevant information to measure impact of drug innovation.

Vital Directions for Health and Health Care: Priorities From a National Academy of Medicine Initiative.

Importance: Recent discussion has focused on questions related to the repeal and replacement of portions of the Affordable Care Act (ACA). However, issues central to the future of health and health care in the United States transcend the ACA provisions receiving the greatest attention. Initiatives directed to certain strategic and infrastructure priorities are vital to achieve better health at lower cost. Objectives: To review the most salient health challenges and opportunities facing the United States, to identify practical and achievable priorities essential to health progress, and to present policy initiatives critical to the nation's health and fiscal integrity. Evidence Review: Qualitative synthesis of 19 National Academy of Medicine-commissioned white papers, with supplemental review and analysis of publicly available data and published research findings. Findings: The US health system faces major challenges. Health care costs remain high at $3.2 trillion spent annually, of which an estimated 30% is related to waste, inefficiencies, and excessive prices; health disparities are persistent and worsening; and the health and financial burdens of chronic illness and disability are straining families and communities. Concurrently, promising opportunities and knowledge to achieve change exist. Across the 19 discussion papers examined, 8 crosscutting policy directions were identified as vital to the nation's health and fiscal future, including 4 action priorities and 4 essential infrastructure needs. The action priorities-pay for value, empower people, activate communities, and connect care-recurred across the articles as direct and strategic opportunities to advance a more efficient, equitable, and patient- and community-focused health system. The essential infrastructure needs-measure what matters most, modernize skills, accelerate real-world evidence, and advance science-were the most commonly cited foundational elements to ensure progress. Conclusions and Relevance: The action priorities and essential infrastructure needs represent major opportunities to improve health outcomes and increase efficiency and value in the health system. As the new US administration and Congress chart the future of health and health care for the United States, and as health leaders across the country contemplate future directions for their programs and initiatives, their leadership and strategic investment in these priorities will be essential for achieving significant progress.