Reward Volume Research Articles

Why is it so hard for academic medical centers to succeed in value-based care?

Academic medical centers (AMCs) excel in many ways, but struggle to succeed at delivering cost-effective care in value-based payment models. To the extent these payment models become more widespread, or mandatory, this could be a giant risk to the future success of AMCs. Many attributes of AMCs that have served them well in a fee-for-service payment system may hinder the transformation needed to succeed in value-based care. Much of the underperformance of AMCs may be explained by two core competencies that AMCs lack: the limited ability to redesign clinical workflows and inability to change their economic relationships with their own specialists and primary care providers. These limitations, in turn, flow from a combination of electronic medical record systems that lock-in existing practice patterns, compensation systems that reward volume over value, organizational structures that make it very hard to drive clinicians to change, workforces with too many specialists, and complex accounting systems. To preserve current margins in value-based care, AMCs need to reduce their cost structures and gain new skills in primary and preventive care. Alternative, AMCs may choose to eschew value-based care and raise their prices for fee-for-service to offset declines in patient volume.

Mice Exposed to Chronic low‐dose Ethanol Exhibit Reduced Sensitivity to Changes in Magnitude of Reward

While approximately 2 billion individuals consume alcohol worldwide, the majority of these individuals to not exhibit drinking patterns consistent with alcohol use disorders (AUDs). Efforts have been made in investigating and characterizing the adverse effects on learning, memory and reward seeking with individuals afflicted with AUDs in a pursuit of therapeutic advancements. However, sub‐diagnostic alcohol effects have been understudied, despite the large number of low‐dose alcohol drinkers and the potential for low dose alcohol to impact both brain and behavior.Data from our lab has shown that low‐dose alcohol exposure enhances reward motivation in male, but not female, mice, but the mechanism of this is effect is unclear. Thus, we investigated the effects of low‐dose alcohol exposure on sensitivity to change in reward magnitude. A group of adult male C57BL6J mice were trained to self‐administer a 20 ul sucrose reward and received either a low‐dose ethanol (0.5g/kg) or saline injection 1 hour after training. To assess motivation, we used a progressive ratio (PR) task in which the effort required to earn the sucrose reward was increased linearly. Mice received multiple counterbalanced PR sessions in which the progressive schedule remained the same, but the reward magnitude was changed from 20ul (baseline) to 35ul, 25ul, 15ul or 5ul in counterbalanced sessions.Consistent with sensitivity to changes in reward value, saline control mice reduced or increased responding when reward volume was reduced or increased, respectively. Similar to saline controls, chronic low‐dose ethanol exposed mice increased their responding when reward volumes were increased compared to the 20ul baseline. However, ethanol exposed mice did not reduce responding to small reductions in reward magnitude. This observation in low‐dose ethanol mice suggests either a failure to detect reductions in reward magnitude or a dissociation between reduced reward magnitude and behavioral response. This lack of strategizing behavior to maintain effort‐to‐reward balance by ethanol exposed mice may imply that chronic low‐dose ethanol exposed mice may perceive greater reward value than controls even at reduced volume and implicates even low‐dose ethanol as a contributor to aberrant reward processing.

The Effect of Network-Level Payment Models on Care Network Performance: A Scoping Review of the Empirical Literature.

Introduction:Traditional payment models reward volume rather than value. Moving away from reimbursing separate providers to network-level reimbursement is assumed to support structural changes in health care organizations that are necessary to improve patient care. This scoping review evaluates the performance of care networks that have adopted network-level payment models.Methods:A scoping review of the empirical literature was conducted according to the five-step York framework. We identified indicators of performance, categorized them in four categories (quality, utilization, spending and other consequences) and scored whether performance increased, decreased, or remained stable due to the payment model.Results:The 76 included studies investigated network-level capitation, disease-based bundled payments, pay-for-performance and blended global payments. The majority of studies stem from the USA. Studies generally concluded that performance in terms of quality and utilization increased or remained stable. Most payment models were associated with improved spending performance. Overall, our review shows that network-level payment models are moderately successful in improving network performance.Discussion/conclusion:As health care networks are increasingly common, it seems fruitful to continue experimenting with reimbursement models for health care networks. It is also important to broaden the scope to not only scrutinize outcomes, but also the contexts and mechanisms that lead to certain outcomes.

Two-dimensional reward evaluation in mice

When choosing among multi-attribute options, integrating the full information may be computationally costly and time-consuming. So-called non-compensatory decision rules only rely on partial information, for example when a difference on a single attribute overrides all others. Such rules may be ecologically more advantageous, despite being economically suboptimal. Here, we present a study that investigates to what extent animals rely on integrative rules (using the full information) versus non-compensatory rules when choosing where to forage. Groups of mice were trained to obtain water from dispensers varying along two reward dimensions: volume and probability. The mice’s choices over the course of the experiment suggested an initial reliance on integrative rules, later displaced by a sequential rule, in which volume was evaluated before probability. Our results also demonstrate that while the evaluation of probability differences may depend on the reward volumes, the evaluation of volume differences is seemingly unaffected by the reward probabilities.

Pharmacological evidence for the implication of noradrenaline in effort.

The trade-off between effort and reward is one of the main determinants of behavior, and its alteration is at the heart of major disorders such as depression or Parkinson's disease. Monoaminergic neuromodulators are thought to play a key role in this trade-off, but their relative contribution remains unclear. Rhesus monkeys (Macaca mulatta) performed a choice task requiring a trade-off between the volume of fluid reward and the amount of force to be exerted on a grip. In line with a causal role of noradrenaline in effort, decreasing noradrenaline levels with systemic clonidine injections (0.01 mg/kg) decreased exerted force and enhanced the weight of upcoming force on choices, without any effect on reward sensitivity. Using computational modeling, we showed that a single variable ("effort") could capture the amount of resources necessary for action and control both choices (as a variable for decision) and force production (as a driving force). Critically, the multiple effects of noradrenaline manipulation on behavior could be captured by a specific modulation of this single variable. Thus, our data strongly support noradrenaline's implication in effort processing.

Effects of reward magnitude frames on measures of delay discounting in a hypothetical money scenario.

The current study analyzed the effects of three frames of reward magnitude-quantity, volume, and duration-on the rate at which college students discounted hypothetical, delayed monetary rewards. Hypothetical scenarios were presented using the fill-in-the-blank discounting questionnaire and participants made choices between immediate and delayed hypothetical monetary rewards. Scenarios framed the monetary choices as (a) quantity of dollar bills, (b) height (inches) of a stack of dollar bills, and (c) duration of time spent in a hypothetical cash machine to collect dollar bills. For each scenario, participants' subjective values were used to calculate the area under the curve (AuC). Framing resulted in a moderate effect size: The duration frame yielded significantly smaller AuC values compared to the quantity and volume frames. Thus, the framing of reward magnitude was a significant variable in controlling discounting rates for hypothetical, delayed monetary rewards. Subsequent investigations should be aware of the independent effects of the reward magnitude frames on delay discounting rates.

White paper addresses VBP opportunities, challenges for BH providers

Health care payments continue to evolve and shift away from fee‐for‐service payment systems that typically reward volume and move to value‐based payment (VBP) models that incentivize high‐quality, cost‐effective care. While this is happening more for physical health services, there's more uncertainty about the role of behavioral health. A new white paper aims to tackle that question with information about existing models that have been implemented along with recommendations for federal and state policymakers.

Stimulus Context and Reward Contingency Induce Behavioral Adaptation in a Rodent Tactile Detection Task.

Behavioral adaptation is a prerequisite for survival in a constantly changing sensory environment, but the underlying strategies and relevant variables driving adaptive behavior are not well understood. Many learning models and neural theories consider probabilistic computations as an efficient way to solve a variety of tasks, especially if uncertainty is involved. Although this suggests a possible role for probabilistic inference and expectation in adaptive behaviors, there is little if any evidence of this relationship experimentally. Here, we investigated adaptive behavior in the rat model by using a well controlled behavioral paradigm within a psychophysical framework to predict and quantify changes in performance of animals trained on a simple whisker-based detection task. The sensory environment of the task was changed by transforming the probabilistic distribution of whisker deflection amplitudes systematically while measuring the animal's detection performance and corresponding rate of accumulated reward. We show that the psychometric function deviates significantly and reversibly depending on the probabilistic distribution of stimuli. This change in performance relates to accumulating a constant reward count across trials, yet it is exempt from changes in reward volume. Our simple model of reward accumulation captures the observed change in psychometric sensitivity and predicts a strategy seeking to maintain reward expectation across trials in the face of the changing stimulus distribution. We conclude that rats are able maintain a constant payoff under changing sensory conditions by flexibly adjusting their behavioral strategy. Our findings suggest the existence of an internal probabilistic model that facilitates behavioral adaptation when sensory demands change.SIGNIFICANCE STATEMENT The strategy animals use to deal with a complex and ever-changing world is a key to understanding natural behavior. This study provides evidence that rodent behavioral performance is highly flexible in the face of a changing stimulus distribution, consistent with a strategy to maintain a desired accumulation of reward.

Gender dimorphism of brain reward system volumes in alcoholism

The brain's reward network has been reported to be smaller in alcoholic men compared to nonalcoholic men, but little is known about the volumes of reward regions in alcoholic women. Morphometric analyses were performed on magnetic resonance brain scans of 60 long-term chronic alcoholics (ALC; 30 men) and 60 nonalcoholic controls (NC; 29 men). We derived volumes of total brain, and cortical and subcortical reward-related structures including the dorsolateral prefrontal (DLPFC), orbitofrontal, and cingulate cortices, and the temporal pole, insula, amygdala, hippocampus, nucleus accumbens septi (NAc), and ventral diencephalon (VDC). We examined the relationships of the volumetric findings to drinking history. Analyses revealed a significant gender interaction for the association between alcoholism and total reward network volumes, with ALC men having smaller reward volumes than NC men and ALC women having larger reward volumes than NC women. Analyses of a priori subregions revealed a similar pattern of reward volume differences with significant gender interactions for DLPFC and VDC. Overall, the volume of the cerebral ventricles in ALC participants was negatively associated with duration of abstinence, suggesting decline in atrophy with greater length of sobriety.

Getting Value from Health Spending: Going Beyond Payment Reform

It is widely held that fee-for-service (FFS) payment systems reward volume and intensity of services, contributing to overall cost inflation, while doing little to reward quality, efficiency, or care coordination. Recently, The National Commission on Physician Payment Reform (sponsored by SGIM) has recommended that payers "should largely eliminate stand-alone fee-for-service payment to medical practices because of its inherent inefficiencies and problematic financial incentives." As the current and former Chief Medical Officers of a large national insurer, we agree that payment reform is a critical component of health care modernization. But calls to transform payment simultaneously go too far, and don't go far enough. Based on our experience, we believe there are several critical ingredients that are either missing or under-emphasized in most payment reform proposals, including: health care is local so no one size fits all; upgrading performance measures; monitoring/overcoming unintended consequences; using a full toolbox to achieve transformation; and ensuring that the necessary components for successful delivery reform are in place. Thinking holistically and remembering that healthcare is a complex adaptive system are crucial to achieving better results for patients and the health system.

Representation of Spatial- and Object-Specific Behavioral Goals in the Dorsal Globus Pallidus of Monkeys during Reaching Movement

The dorsal aspect of the globus pallidus (GP) communicates with the prefrontal cortex and higher-order motor areas, indicating that it plays a role in goal-directed behavior. We examined the involvement of dorsal GP neurons in behavioral goal monitoring and maintenance, essential components of executive function. We trained two macaque monkeys to choose a reach target based on relative target position in a spatial goal task or a target shape in an object-goal task. The monkeys were trained to continue to choose a certain behavioral goal when reward volume was constant and to switch the goals when the volume began to decrease. Because the judgment for the next goal was made in the absence of visual signals, the monkeys were required to monitor and maintain the chosen goals during the reaching movement. We obtained three major findings. (1) GP neurons reflected more of the relative spatial position than the shape of the reaching target during the spatial goal task. During the object-goal task, the shape of the reaching object was represented more than the relative position. (2) The selectivity of individual neurons for the relative position was enhanced during the spatial goal task, whereas the object-shape selectivity was enhanced during the object-goal task. (3) When the monkeys switched the goals, the selectivity for either the position or shape also switched. Together, these findings suggest that the dorsal GP is involved in behavioral goal monitoring and maintenance during execution of goal-oriented actions, presumably in collaboration with the prefrontal cortex.

Risk indifference in white-eared hummingbirds (Hylocharis leucotis) confronting multiple foraging options

Variations in the quality or quantity of a food source determines if an animal takes the risk of spending energy searching for or eating it. Hummingbirds have been traditionally catalogued as risk-averse foragers. However, the inclusion of more than 2 options in a foraging set for risk-sensitive experiments has resulted in the observation that some hummingbird species preferred intermediate risk even if they had been risk-averse in a traditional binary risk experiment. These contrasting results suggest an effect of having multiple foraging options that had been ignored due to the design of previous risk experiments. Here, we studied the influence of varying reward volume (Experiment 1) or sugar concentration (Experiment 2) on choice behavior of white-eared hummingbirds, Hylocharis leucotis, by recording their visits to feed from a sucrose solution located in 4 artificial floral arrays associated with constant, low, medium, and high variance. In both experiments, each of the vertical arrays was evaluated in a training stage and a test stage. The birds visited all the arrays without discriminating among them, and thus were indifferent to variations in the volume or sugar concentration of reward. Thus, there was no influence of variance of nectar volume and sugar concentration on the choice behavior of the birds, ruling out the possibility that white-eared hummingbirds are risk sensitive under these conditions of 4 foraging alternatives.

What can the observation of nonzero curvature tell us?

The eternally inflating multiverse provides a consistent framework to understand coincidences and fine-tuning in the universe. As such, it provides the possibility of finding another coincidence: if the amount of slow-roll inflation was only slightly more than the anthropic threshold, then spatial curvature might be measurable. We study this issue in detail, particularly focusing on the question: "If future observations reveal nonzero curvature, what can we conclude?" We find that whether an observable signal arises or not depends crucially on three issues: the cosmic history just before the observable inflation, the measure adopted to define probabilities, and the nature of the correlation between the tunneling and slow-roll parts of the potential. We find that if future measurements find positive curvature at \Omega_k < -10^-4, then the framework of the eternally inflating multiverse is excluded with high significance. If the measurements instead reveal negative curvature at \Omega_k > 10^-4, then we can conclude (1) diffusive (new or chaotic) eternal inflation did not occur in our immediate past; (2) our universe was born by a bubble nucleation; (3) the probability measure does not reward volume increase; and (4) the origin of the observed slow-roll inflation is an accidental feature of the potential, not due to a theoretical mechanism. Discovery of \Omega_k > 10^-4 would also give us nontrivial information about the correlation between tunneling and slow-roll; e.g. a strong correlation favoring large N would be excluded in certain measures. We also ask whether the current constraint on \Omega_k is consistent with multiverse expectations, finding that the answer is yes, except for certain cases. In the course of this work we were led to consider vacuum decay branching ratios, and found that it is more likely than one might guess that the decays are dominated by a single channel.

Connecting Care Through the Clinic and Community for a Healthier America

Yet, to date, our society has not yet optimally aligned the individual and community forces that can best foster health for all. For too long, fragmentation has ruled the day. In particular, the nation’s healthcare systems have focused predominantly on sick care, plagued by episodic and uncoordinated delivery, multiple paper-based clinical records, rising costs without related quality improvement, and reimbursement systems that reward volume and not value. Moreover, a suboptimal focus on prevention, without engagement of and integration with the broader public health community, has added to the fragmentation. As a result, patients and populations alike have not consistently reached their full health potential. Fortunately, a new day has dawned. The Affordable CareAct (ACA), the health reform lawof 2010, offers the romise of greater insurance coverage formillions. It also nits together the themes of care coordination and health romotion for both the clinic and the community.Many provisions offer opportunities for healthcare providers to partner with public health agencies and community organizations for the benefit of their patients. Hence, the various components of the ACA provide an unprecedented opportunity to overcome fragmentation and integrate primary care and public health. Doing so recognizes that health arises not simply from a visit to a doctor’s office, but also, more broadly, from where people live, labor, learn, play, and pray. Indeed, the overarching oals of Healthy People 2020 emphasize a life span aproach to health promotion and a society in which the ealthy choice represents the easier choice.

Physical Therapy in a Value-Based Healthcare World

Musculoskeletal conditions are important contributors to United States healthcare spending and are certain to play an important role in the future as the population continues to age. Almost half of the population of the United States experiences a musculoskeletal condition annually. Meeting the needs of these individuals within a changing healthcare delivery and reimbursement environment prompted a recent Summit sponsored by the United States Bone and Joint Initiative (USBJI). The Summit dealt with a topic critical to the future of healthcare for clinicians, consumers, and payers alike: value. We do not operate within a value-based healthcare system. Our current delivery system continues to reward volumes, not value. Failure to focus on value has had devastating consequences. The challenge of shifting from a volume-based to a value-based system is central to the future of healthcare. Discussion and action will be critical for the physical therapy profession moving into the future.

Flower constancy in honey bee workers (Apis mellifera) depends on ecologically realistic rewards

As first described by Aristotle, honey bee (Apis mellifera) workers show a strong tendency to visit flowers of only one type during a foraging trip. It is known that workers rapidly learn a flower colour when rewarded with artificial nectar (sucrose solution). However, some previous studies report that the degree of constancy after training is unaffected by reward quantity and quality when bees are tested in an array of artificial flowers of two easily distinguished colours, such as blue and yellow. One possible reason for this surprising result is that large reward volumes were compared. This is likely to mask the abilities of foragers to make adaptive decisions under more realistic conditions. To test this possibility, we offered untrained honey bee workers ecologically relevant rewards (0.5, 1 or 2 μl of 0.5 or 1 mol l(-1) sucrose solution) on one or two consecutive yellow or blue artificial flowers and then recorded which flowers the bees subsequently landed on in an array of 40 empty flowers. The results showed that an increase in all three factors (volume, concentration and number of rewards) significantly increased constancy (proportion of visits to flowers of the trained colour) and persistence (number of flowers visited) during the foraging bout. Constancy for the least rewarding situation was 75.9% compared with 98.6% for the most rewarding situation. These results clearly show that honey bee workers do become more constant to blue or yellow with increasing nectar rewards, provided that the rewards used are ecologically realistic. As the most rewarding conditions led to nearly 100% constancy, further reward increases during training would not have been able to further increase constancy. This explains why previous studies comparing large rewards found no effect of reward on constancy.

Improving Colonoscopy Quality Through Health-Care Payment Reform

Problems with the quality of colonoscopy are well recognized. Variation in colonoscopist performance is compounded by payment structures that reward volume rather than quality. Payment reform has emerged as one strategy to address these and more systemic problems in the quality of health care. Various forms of value-based purchasing might encourage a realignment of incentives, and allow reimbursement to be directly linked with clinically important goals of colonoscopy. This paper proposes criteria for the selection of quality measures, and three candidate indicators to define quality for the purpose of payment reform in colonoscopy: cecal intubation rate, adenoma detection rate, and recommended post-polypectomy surveillance interval. These measures represent valid, credible, and reliable indicators of the quality of colonoscopy for colorectal cancer screening and surveillance. Payment reform should explicitly link public reporting and performance on these quality measures to payment for colonoscopy.

Dissociable Roles of the Medial Prefrontal Cortex and Nucleus Accumbens Core in Goal-Directed Actions for Differential Reward Magnitude

The medial prefrontal cortex (mPFC) and nucleus accumbens (NAc) are 2 structures within a larger corticolimbic network mediating goal-directed actions, especially when the procurement of different goals is sensitive to impulsive tendencies. The present study investigated the role of these structures in goal-directed action for differential reward by training rats to respond for sucrose reward at a nosepoke operandum such that longer duration nosepokes (up to 2 s) resulted in correspondingly larger volumes of reward. After 16 weeks of training, neurotoxic lesions of either the mPFC or the NAc-core were performed, followed by reassessment of sustained response behavior. Lesions of mPFC increased choice impulsivity by shifting responding away from large rewards toward rewards of smaller sizes. The total volume of reward earned remained unchanged, thereby dissociating the lesion effects on response parameters from overall motivation for reward. In contrast, NAc-core lesions decreased the total amount of responding and total volume of reward earned without altering choice impulsivity across differing nosepoke durations and reward sizes. These results suggest that the mPFC mediates the ability to maintain behavioral responding over longer durations for larger magnitude rewards, while the NAc-core mediates the initiation of responding, perhaps by affecting motivational drive, independent of reward magnitude.

The effect of foraging specialization on various learning tasks in the honey bee (Apis mellifera)

Honey bee foragers may collect nectar, pollen, water, or propolis, and their foraging specialization has been associated with several behavioral traits. By conditioning of the proboscis extension response (PER), we compared the performance of foragers that collected nectar, pollen, both nectar and pollen, or water in several learning and choice assays. Foragers were first tested in a three-trial olfactory associative learning assay. For further tests, we selected only good learners that responded in two out of three conditioning trials. One group was tested in an additional olfactory associative learning assay involving different reward volumes and concentrations. Another group was tested for risk sensitivity in a two-alternative forced-choice PER procedure and then in a latent inhibition (LI) assay. Levels of acquisition in olfactory associative learning were highest in pollen and water foragers, and better acquisition was associated with collection of heavier pollen loads and smaller and lighter nectar loads of lower sugar concentration. Among the good learners, pollen foragers still showed better acquisition than nectar foragers when rewarded with several volumes and concentrations of sucrose solution. Pollen and nectar foragers were equally risk averse, preferring a constant reward to a variable one, and choice was not affected by pollen load weight. Contrary to a previous study, pollen and nectar foragers were similarly affected by LI. We discuss possible explanations for the discrepancy between the two studies. Overall, our results suggest that differences between foraging groups in sensitivity to various stimuli may not correspond to differences in choice behavior.

Learning and Memory During Foraging of The Blue Orchard Bee, Osmia lignaria Say (Hymenoptera: Megachilidae)

Abstract Social bees have been widely used as model systems for studying learning and memory. Much less is known about these phenomena in solitary bees, in spite of the fact that most bee species of the world are solitary. We explore the ability of the solitary blue orchard bee, Osmia lignaria Say, to learn and remember information when foraging. First we tested innate flower color preference using blue and white flower patches, and yellow and blue flower patches. The blue orchard bees showed a marked color preference for blue flowers in blue-white as well as in blue-yellow flower patches, even though all flowers provided the same reward. However, when white flowers offered the greater reward (either quality/molarity or quantity/volume) in blue-white dimorphic floral patches, the preference for blue readily decreased, which was not observed in control bees. Learning occurred more rapidly when a difference in reward volume rather than reward molarity was used. These results were approximately the same for ...