Understanding contributors to racial and ethnic inequities in COVID-19 incidence and mortality rates

BACKGROUND: Racial inequities in Coronavirus 2019 (COVID-19) have been reported over the course of the pandemic, with Black, Hispanic/Latinx, and Native American individuals suffering higher case rates and more fatalities than their White counterparts. METHODS: We used a unique statewide dataset of confirmed COVID-19 cases across Missouri, linked with historical statewide hospital data. We examined differences by race and ethnicity in raw population-based case and mortality rates. We used patient-level regression analyses to calculate the odds of mortality based on race and ethnicity, controlling for comorbidities and other risk factors. RESULTS: As of September 10, 2020 there were 73,635 confirmed COVID-19 cases in the State of Missouri. Among the 64,526 case records (87.7% of all cases) that merged with prior demographic and health care utilization data, 12,946 (20.1%) were Non-Hispanic (NH) Black, 44,550 (69.0%) were NH White, 3,822 (5.9%) were NH Other/Unknown race, and 3,208 (5.0%) were Hispanic. Raw cumulative case rates for NH Black individuals were 1,713 per 100,000 population, compared with 2,095 for NH Other/Unknown, 903 for NH White, and 1,218 for Hispanic. Cumulative COVID-19-related death rates for NH Black individuals were 58.3 per 100,000 population, compared with 38.9 for NH Other/Unknown, 19.4 for NH White, and 14.8 for Hispanic. In a model that included insurance source, history of a social determinant billing code in the patient\u27s claims, census block travel change, population density, Area Deprivation Index, and clinical comorbidities, NH Black race (OR 1.75, 1.51-2.04, p\u3c0.001) and NH Other/Unknown race (OR 1.83, 1.36-2.46, p\u3c0.001) remained strongly associated with mortality. CONCLUSIONS: In Missouri, COVID-19 case rates and mortality rates were markedly higher among NH Black and NH Other/Unknown race than among NH White residents, even after accounting for social and clinical risk, population density, and travel patterns during COVID-19

High-gain parametric amplification for the generation of quantum states of light

Thesis (Ph. D.)--University of Rochester. Institute of Optics, 2001. Missing page xi.The novel quantum statistical properties of the two-photon entangled states generated by spontaneous parametric downconversion have been utilized in a variety of fourth-order interferometric configurations. The extent to which the intense light produced by an unseeded parametric amplifier (optical parametric generator) retains these desirable properties is explored in a series of calculations. Common fourth-order interferometric configurations using two-photon entangled states are summarized, with an emphasis on the Hong-Ou-Mandel and Mach-Zehnder interferometers. This summary is followed by a review of recent proposals for the exploitation of entangled states for sub-Rayleigh-limit imaging. The limitations of using parametric downconversion at two-photon levels are discussed and the replacement of two-photon interferometric sources with the multiphoton output of a high-gain optical parametric generator is considered. The output of the Hong-Ou-Mandel interferometer, Mach-Zehnder interferometer, and quantum lithography configurations as a function of single-pass gain is determined, and the interpretation of these results in the context of multiple photon pair contributions to interferometric patterns is presented. The analysis of the high-gain optical parametric generator as a fourth-order interferometric source is then extended to the case of multiple signal and idler output modes. The impact of the system transfer characteristics on the desired interferometric properties is discussed. The initiation of beam filamentation by vacuum fluctuations is considered, and this four-wave mixing process is compared to parametric downconversion as a source for fourth-order interferometric applications. We conclude by contrasting the states produced by high-gain optical parametric generation with coherent states and the states produced by seeded optical parametric amplification as sources for fourth-order interferometric configurations

Nonclassical two-photon interferometry and lithography with high-gain parametric amplifiers

Optical parametric amplification is a process that leads to the generation of quantum states of light. In the limit of low single-pass gain, this process is often referred to as parametric down conversion, and produces entangled two-photon states. Such states have played a key role in recent studies of quantum optical effects such as quantum teleportation. As the gain of the parametric amplification process is increased, the generated light field still possesses strong quantum correlations, but not of the sort associated with two-photon states. Here we present an analysis of the output state of a parametric amplifier as a function of the single-pass gain, and we find certain signatures of quantum light (such as the vanishing of the coincidence rate in a Hong-Ou-Mandel interferometer) disappear in the high-gain limit, whereas others (such as the existence of two-photon interference fringes) remain. Consequently, the intense light field generated by a high-gain parametric amplifier can be utilized in such applications of quantum optics

Parametric downconversion vs optical parametric amplification: a comparison of their quantum statistics

The extent to which the intense light generated by an unseeded, high-gain optical parametric amplifier retains the desired quantum statistical properties of the individual photon pairs generated by spontaneous parametric downconversion is analysed. It is shown that certain but not all of these properties are retained, with important implications for applications of quantum optics

Adjusting for social risk factors impacts performance and penalties in the hospital readmissions reduction program

OBJECTIVE: Medicare\u27s Hospital Readmissions Reduction Program (HRRP) does not account for social risk factors in risk adjustment, and this may lead the program to unfairly penalize safety-net hospitals. Our objective was to determine the impact of adjusting for social risk factors on HRRP penalties. STUDY DESIGN: Retrospective cohort study. DATA SOURCES/STUDY SETTING: Claims data for 2 952 605 fee-for-service Medicare beneficiaries with acute myocardial infarction (AMI), congestive heart failure (CHF) or pneumonia from December 2012 to November 2015. PRINCIPAL FINDINGS: Poverty, disability, housing instability, residence in a disadvantaged neighborhood, and hospital population from a disadvantaged neighborhood were associated with higher readmission rates. Under current program specifications, safety-net hospitals had higher readmission ratios (AMI, 1.020 vs 0.986 for the most affluent hospitals; pneumonia, 1.031 vs 0.984; and CHF, 1.037 vs 0.977). Adding social factors to risk adjustment cut these differences in half. Over half the safety-net hospitals saw their penalty decline; 4-7.5 percent went from having a penalty to having no penalty. These changes translated into a $17 million reduction in penalties to safety-net hospitals. CONCLUSIONS: Accounting for social risk can have a major financial impact on safety-net hospitals. Adjustment for these factors could reduce negative unintended consequences of the HRRP