What is the orbit model of behavioral therapy?
The ORBIT model provides a progressive, clinically relevant approach to increasing the number of evidence-based behavioral treatments available to prevent and treat chronic diseases. (PsycINFO Database Record From ideas to efficacy: The ORBIT model for developing behavioral treatments for chronic diseases Health Psychol.
Is the orbit model relevant to treating chronic diseases?
Conclusions: The ORBIT model provides a progressive, clinically relevant approach to increasing the number of evidence-based behavioral treatments available to prevent and treat chronic diseases. (PsycINFO Database Record
What does orbit stand for?
The Obesity-Related Behavioral Intervention Trials (ORBIT) model for behavioral treatment development features a flexible and progressive process, prespecified clinically significant milestones for forward movement, and return to earlier stages for refinement and optimization.
What are the methods of orbit simulation?
Orbit simulation methods. Orbit models are typically propagated in time and space using special perturbation methods. This is performed by first modeling the orbit as a Keplerian orbit. Then perturbations are added to the model to account for the various perturbations that affect the orbit.
Core Concepts
Love is a member's score based on their relative engagement and impact in the community. All members have a Love metric, and this number is what determines a member's Orbit Level.
Further Exploration
The Orbit Model is open source and available on GitHub. We welcome discussions about the model on GitHub.
What causes orbits to become perturbed from a perfect Keplerian orbit?
Perturbing forces cause orbits to become perturbed from a perfect Keplerian orbit. Models for each of these forces are created and executed during the orbit simulation so their effects on the orbit can be determined.
How are orbits propagated?
Orbit models are typically propagated in time and space using special perturbation methods. This is performed by first modeling the orbit as a Keplerian orbit. Then perturbations are added to the model to account for the various perturbations that affect the orbit.
What are the causes of perturbations in orbits?
Gravitational forces from third bodies can cause perturbations to an orbit. For example, the Sun and Moon cause perturbations to Orbits around the Earth. These forces are modeled in the same way that gravity is modeled for the primary body by means of Direct gravitational N-body simulations. Typically, only a spherical point-mass gravity model is used for modeling effects from these third bodies. Some special cases of third-body perturbations have approximate analytic solutions. For example, perturbations for the right ascension of the ascending node and argument of perigee for a circular Earth orbit are:
What are perturbing forces in orbit modeling?
Perturbing forces may include gravitational attraction from other bodies besides the primary, solar wind, drag, magnetic fields, and propulsive forces.
What is orbit modeling?
Orbit modeling is the process of creating mathematical models to simulate motion of a massive body as it moves in orbit around another massive body due to gravity. Other forces such as gravitational attraction from tertiary bodies, air resistance, solar pressure, or thrust from a propulsion system are typically modeled as secondary effects. Directly modeling an orbit can push the limits of machine precision due to the need to model small perturbations to very large orbits. Because of this, perturbation methods are often used to model the orbit in order to achieve better accuracy.
Why is it important to model an orbit?
Directly modeling an orbit can push the limits of machine precision due to the need to model small perturbations to very large orbits. Because of this, perturbation methods are often used to model the orbit in order to achieve better accuracy.
What is the primary non-gravitational force acting on satellites in low Earth orbit?
The primary non-gravitational force acting on satellites in low Earth orbit is atmospheric drag. Drag will act in opposition to the direction of velocity and remove energy from an orbit. The force due to drag is modeled by the following equation:
What is the purpose of a phase 3 trial?
The aim of Phase III trials in the ORBIT model is to determine whether an intervention is efficacious under conditions that maximally control for confounding influences; therefore, these studies are an important step in the production of reliable evidence to support an intervention’s effects on a clinical or public health outcome. Typically, efficacy studies are large, well-designed, randomized controlled trials designed to influence public health and/or clinical practice. Randomized designs may not always be feasible, and alternative designs (e.g., regression discontinuity or other quasi-experimental designs) can be used to assess the effect of an intervention. Nonetheless, there are many advantages to the use of a randomized efficacy trial to test the effect of a behavioral intervention. Efficacy studies are designed with attention to methodologic considerations, such as adequate samples sizes and statistical power, to allow reliable evaluations of the intervention’s effects, ensure a high degree of fidelity to the research protocol, and eliminate potential sources of bias. Important considerations in efficacy studies are detailed in quality assessment tools, such as those for controlled interventions (
What is phase Ib in ORBIT?
Phase Ib of ORBIT is devoted to refining the behavioral intervention to establish the delivery mode, duration, intensity, and acceptability needed to achieve clinically important change while keeping the intervention as efficient as possible. A wide variety of experimental (e.g., time series and single case designs) and qualitative methods may be used to ensure that the intervention is sufficiently sound and yet efficient to achieve clinically significant behavioral changes. Phase Ib is completed when researchers are confident that the intervention is “complete and the fixed protocol is ready for testing” (
What is the Orbit model?
The ORBIT model is designed to elaborate on the important early phases of intervention development that are needed to ensure that an intervention is sound and ready for clinical trials. Phase I in the ORBIT model involves two subphases: Ia and Ib. In Phase Ia, the core components of the intervention are defined through the analysis and application of basic scientific, epidemiologic, and formative research findings. Such background research may include the use of focus groups or other methods that provide insights into defining essential components to achieve significant behavior changes. In Phase Ia, researchers may seek to design a conceptually novel intervention or create a novel redesign of an existing intervention. An important task during this phase is to identify a clinical benchmark or milestone for the achievement of clinically significant change. Rather than simply relying on statistically significant changes that may lack clinical import, researchers are pressed to delineate cutoff points or criteria on behavioral measures that are associated with clinically significant health improvements regarding the problem of concern (
What happens to weight retention at 6 months?
). Weight retained at 6 months adds to long-term weight gain in women and may increase risk of chronic disease (. Impact of perinatal weight change on long-term obesity and obesity-related illnesses.
What are the components of the drug discovery model?
The components of that model include Step 1, discovery and development of potentially useful compounds; Step 2, preclinical research on dosing and safety in vivo and in vitro studies; and Step 3, controlled clinical trials to show efficacy (. U.S. Food and Drug Administration, 2018.
What is phase II in a clinical trial?
Phase II involves the use of single-group proof-of-concept, feasibility, and preliminary efficacy studies to show the feasibility and capacity of the intervention to produce change in an intermediate endpoint. Phase III involves the use of randomized controlled trials to test the efficacy of the intervention.
Why is the Orbit model important?
Because the ORBIT model is a relatively new and rigorous process for developing an intervention, it engenders a number of questions from potential intervention developers. One of the first questions nurse-researchers and other intervention developers may ask is whether the application of the ORBIT model is feasible, because it entails a number of smaller studies in Phases I and II, and researchers may be pressured to conduct larger funded studies. However, local sources of seed money often exist to conduct the preliminary work of Phases I and II, and these results provide a strong foundation for subsequent large efficacy trials. Framing preliminary studies explicitly within the ORBIT model may also enlighten reviewers of small grants about the path being followed toward larger-scale trials and the increased likelihood of the success of those trials given achievements realized during the ORBIT model process. The importance of conducting Phase II studies is underscored by a recent study on the lack of feasibility of a well-researched behavioral intervention when applied to underserved women during the postpartum period (
