John R. Parker

Bio: John R. Parker is an academic researcher from Durham University. The author has contributed to research in topics: Hyperbolic space & Relatively hyperbolic group. The author has an hindex of 24, co-authored 84 publications receiving 1575 citations. Previous affiliations of John R. Parker include University of Warwick & University of Maryland, College Park.

Copayment Reductions Generate Greater Medication Adherence In Targeted Patients

Abstract: A large value-based insurance design program offered by Blue Cross Blue Shield of North Carolina eliminated generic medication copayments and reduced copayments for brand-name medications. Our study showed that the program improved adherence to medications for diabetes, hypertension, hyperlipidemia, and congestive heart failure. We found that adherence improved for enrollees, ranging from a gain of 3.8 percentage points for patients with diabetes to 1.5 percentage points for those taking calcium-channel blockers, when compared to others whose employers did not offer a similar program. An examination of longer-term adherence and trends in health care spending is still needed to provide a compelling evidence base for value-based insurance design.

Geometry of quaternionic hyperbolic manifolds

Abstract: We develop some of the basic theory of quaternionic hyperbolic geometry. We give necessary criteria for groups of quaternionic hyperbolic motions to be discrete. We give lower bounds on the volumes of cusped quaternionic hyperbolic manifolds.

Complex hyperbolic ideal triangle groups.

Abstract: In the real hyperbolic plane, reflections in three mutually asymptotic geodesics freely generate a discrete group having the triangle bounded by these geodesics äs its fundamental domain. This paper is concerned with the analogous question for groups generated by inversions in three mutually asymptotic complex geodesics in complex hyperbolic space. Such an \"ideal triangle group\" is determined by a triple of points on the boundary of complex hyperbolic space; such triples are parametrised by a single real number (the Cartan angular invariant) in the interval [ — /2, /2]. The purpose of this paper is to investigate for which values of the Cartan invariant the corresponding representation is a discrete embedding.

The geometry of the Eisenstein-Picard modular group

Abstract: The Eisenstein-Picard modular group ${\rm PU}(2,1;\mathbb {Z}[\omega])$ is defined to be the subgroup of ${\rm PU}(2,1)$ whose entries lie in the ring $\mathbb {Z}[\omega]$, where $\omega$ is a cube root of unity. This group acts isometrically and properly discontinuously on ${\bf H}^2_\mathbb{C}$, that is, on the unit ball in $\mathbb {C}^2$ with the Bergman metric. We construct a fundamental domain for the action of ${\rm PU}(2,1;\mathbb {Z}[\omega])$ on ${\bf H}^2_\mathbb {C}$, which is a 4-simplex with one ideal vertex. As a consequence, we elicit a presentation of the group (see Theorem 5.9). This seems to be the simplest fundamental domain for a finite covolume subgroup of ${\rm PU}(2,1)$

Phd by thesis

Abstract: Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Delivering High-Quality Cancer Care: Charting a New Course for a System in Crisis

Abstract: In the United States, approximately 14 million people have had cancer and more than 1.6 million new cases are diagnosed each year. However, more than a decade after the Institute of Medicine (IOM) first studied the quality of cancer care, the barriers to achieving excellent care for all cancer patients remain daunting. Care often is not patient-centered, many patients do not receive palliative care to manage their symptoms and side effects from treatment, and decisions about care often are not based on the latest scientific evidence. The cost of cancer care also is rising faster than many sectors of medicine--having increased to $125 billion in 2010 from $72 billion in 2004--and is projected to reach $173 billion by 2020. Rising costs are making cancer care less affordable for patients and their families and are creating disparities in patients' access to high-quality cancer care. There also are growing shortages of health professionals skilled in providing cancer care, and the number of adults age 65 and older--the group most susceptible to cancer--is expected to double by 2030, contributing to a 45 percent increase in the number of people developing cancer. The current care delivery system is poorly prepared to address the care needs of this population, which are complex due to altered physiology, functional and cognitive impairment, multiple coexisting diseases, increased side effects from treatment, and greater need for social support. Delivering High-Quality Cancer Care: Charting a New Course for a System in Crisis presents a conceptual framework for improving the quality of cancer care. This study proposes improvements to six interconnected components of care: (1) engaged patients; (2) an adequately staffed, trained, and coordinated workforce; (3) evidence-based care; (4) learning health care information technology (IT); (5) translation of evidence into clinical practice, quality measurement and performance improvement; and (6) accessible and affordable care. This report recommends changes across the board in these areas to improve the quality of care. Delivering High-Quality Cancer Care: Charting a New Course for a System in Crisis provides information for cancer care teams, patients and their families, researchers, quality metrics developers, and payers, as well as HHS, other federal agencies, and industry to reevaluate their current roles and responsibilities in cancer care and work together to develop a higher quality care delivery system. By working toward this shared goal, the cancer care community can improve the quality of life and outcomes for people facing a cancer diagnosis.

Interventions to improve adherence to self-administered medications for chronic diseases in the United States: a systematic review

Abstract: Background Suboptimum medication adherence is common in the United States and leads to serious negative health consequences but may respond to intervention. Purpose To assess the comparative effectiveness of patient, provider, systems, and policy interventions that aim to improve medication adherence for chronic health conditions in the United States. Data sources Eligible peer-reviewed publications from MEDLINE and the Cochrane Library indexed through 4 June 2012 and additional studies from reference lists and technical experts. Study selection Randomized, controlled trials of patient, provider, or systems interventions to improve adherence to long-term medications and nonrandomized studies of policy interventions to improve medication adherence. Data extraction Two investigators independently selected, extracted data from, and rated the risk of bias of relevant studies. Data synthesis The evidence was synthesized separately for each clinical condition; within each condition, the type of intervention was synthesized. Two reviewers graded the strength of evidence by using established criteria. From 4124 eligible abstracts, 62 trials of patient-, provider-, or systems-level interventions evaluated 18 types of interventions; another 4 observational studies and 1 trial of policy interventions evaluated the effect of reduced medication copayments or improved prescription drug coverage. Clinical conditions amenable to multiple approaches to improving adherence include hypertension, heart failure, depression, and asthma. Interventions that improve adherence across multiple clinical conditions include policy interventions to reduce copayments or improve prescription drug coverage, systems interventions to offer case management, and patient-level educational interventions with behavioral support. Limitations Studies were limited to adults with chronic conditions (excluding HIV, AIDS, severe mental illness, and substance abuse) in the United States. Clinical and methodological heterogeneity hindered quantitative data pooling. Conclusion Reduced out-of-pocket expenses, case management, and patient education with behavioral support all improved medication adherence for more than 1 condition. Evidence is limited on whether these approaches are broadly applicable or affect longterm medication adherence and health outcomes. Primary funding source Agency for Healthcare Research and Quality.

Interventions to Improve Adherence to Self-administered Medications for Chronic Diseases in the United States

Abstract: This review examined the comparative effectiveness of patient, provider, systems, and policy interventions to improve medication adherence for chronic conditions. It found evidence that reduced out...

Antiretroviral Drugs for Treatment and Prevention of HIV Infection in Adults: 2020 Recommendations of the International Antiviral Society-USA Panel.

Abstract: Importance Data on the use of antiretroviral drugs, including new drugs and formulations, for the treatment and prevention of HIV infection continue to guide optimal practices. Objective To evaluate new data and incorporate them into current recommendations for initiating HIV therapy, monitoring individuals starting on therapy, changing regimens, preventing HIV infection for those at risk, and special considerations for older people with HIV. Evidence Review New evidence was collected since the previous International Antiviral (formerly AIDS) Society–USA recommendations in 2018, including data published or presented at peer-reviewed scientific conferences through August 22, 2020. A volunteer panel of 15 experts in HIV research and patient care considered these data and updated previous recommendations. Findings From 5316 citations about antiretroviral drugs identified, 549 were included to form the evidence basis for these recommendations. Antiretroviral therapy is recommended as soon as possible for all individuals with HIV who have detectable viremia. Most patients can start with a 3-drug regimen or now a 2-drug regimen, which includes an integrase strand transfer inhibitor. Effective options are available for patients who may be pregnant, those who have specific clinical conditions, such as kidney, liver, or cardiovascular disease, those who have opportunistic diseases, or those who have health care access issues. Recommended for the first time, a long-acting antiretroviral regimen injected once every 4 weeks for treatment or every 8 weeks pending approval by regulatory bodies and availability. For individuals at risk for HIV, preexposure prophylaxis with an oral regimen is recommended or, pending approval by regulatory bodies and availability, with a long-acting injection given every 8 weeks. Monitoring before and during therapy for effectiveness and safety is recommended. Switching therapy for virological failure is relatively rare at this time, and the recommendations for switching therapies for convenience and for other reasons are included. With the survival benefits provided by therapy, recommendations are made for older individuals with HIV. The current coronavirus disease 2019 pandemic poses particular challenges for HIV research, care, and efforts to end the HIV epidemic. Conclusion and Relevance Advances in HIV prevention and management with antiretroviral drugs continue to improve clinical care and outcomes among individuals at risk for and with HIV.