The relationship between insurance and health outcomes of diabetes mellitus patients in Maryland: a retrospective archival record study.

BACKGROUND: Past studies examining the health outcomes of diabetes mellitus (DM) patients found that social determinants of health disparities were associated with variabilities in health outcomes. However, improving access to healthcare, such as health insurance, should mitigate negative health outcomes. The aim of the study was to explore the association between four types of health insurance, namely, Medicare Fee-For-Service (FFS), Medicare Managed Care (MC), Private FFS, and Private MC plans, and the health outcomes of DM patients, controlling for patients' social determinants of health. METHODS: This is a retrospective cross-sectional archival record study to explore the relationships between types of health insurance and health outcomes of DM patients who were at least 65 years old, or the elderly. Data was drawn from the 2012 Maryland Clinical Public Use Data and received an exempt status from our Institutional Review Board. Elderly Maryland residents with chronic DM were included in the study, resulting in a sample size of 43,519 individuals. Predictor variables were four types of insurance and health outcome variables were length of hospital stay (LOS), 30-day readmission, and end-stage renal disease (ESRD). Control variables included hospital characteristics, patient characteristics, and social determinants of health. Student's t-tests determined the statistical differences for the control variables between the types of insurance. Multiple hierarchical regression analysis was applied to test the association between insurance plans and LOS, while logistic regression analyses were applied to test the association between insurance plans with 30-day readmission and ESRD. Statistical significance was set at p < 0.05. RESULTS: t-test results indicated minimal statistical differences between the health statuses of patients enrolled in different insurance plans. After factoring out the control variables, regression analyses indicated that Medicare FFS patients had the worst outcome for LOS, 30-day readmission, and ESRD rates. Although patients on Medicare MC plans had lower LOS, 30-day readmission, and ESRD rates compared to those on Medicare FFS, patients enrolled in Private MC plans had the lowest odds of a 30-day readmission and patients enrolled in Private FFS had the lowest odds of an ESRD. CONCLUSIONS: The data suggests that insurance plans were related to the health outcomes of elderly DM patients after considering their social determinants of health. Specifically, DM patients enrolled in managed care and private insurance plans had better health outcomes compared to those on Medicare FFS plans.

Brightly Luminescent CsPbBr3 Nanocrystals through Ultracentrifugation.

Using a combination of density-gradient and analytical ultracentrifugation, we studied the photophysical profile of CsPbBr3 nanocrystal (NC) suspensions by separating them into size-resolved fractions. Ultracentrifugation drastically alters the ligand profile of the NCs, which necessitates postprocessing to restore colloidal stability and enhance quantum yield (QY). Rejuvenated fractions show a 50% increase in QY compared to no treatment and a 30% increase with respect to the parent. Our results demonstrate how the NC environment can be manipulated to improve photophysical performance, even after there has been a measurable decline in the response. Size separation reveals blue-emitting fractions, a narrowing of photoluminescence spectra in comparison to the parent, and a crossover from single- to stretched-exponential relaxation dynamics with decreasing NC size. As a function of edge length, L, our results confirm that the photoluminescence peak energy scales a L-2, in agreement with the simplest picture of quantum confinement.

Bright Silicon Nanocrystals from a Liquid Precursor: Quasi-Direct Recombination with High Quantum Yield.

Silicon nanocrystals (SiNCs) with bright bandgap photoluminescence (PL) are of current interest for a range of potential applications, from solar windows to biomedical contrast agents. Here, we use the liquid precursor cyclohexasilane (Si6H12) for the plasma synthesis of colloidal SiNCs with exemplary core emission. Through size separation executed in an oxygen-shielded environment, we achieve PL quantum yields (QYs) approaching 70% while exposing intrinsic constraints on efficient core emission from smaller SiNCs. Time-resolved PL spectra of these fractions in response to femtosecond pulsed excitation reveal a zero-phonon radiative channel that anticorrelates with QY, which we model using advanced computational methods applied to a 2 nm SiNC. Our results offer additional insight into the photophysical interplay of the nanocrystal surface, quasi-direct recombination, and efficient SiNC core PL.

Neutral Cyclometalated Iridium(III) Complexes Bearing Substituted N-Heterocyclic Carbene (NHC) Ligands for High-Performance Yellow OLED Application.

The synthesis, crystal structure, and photophysics of a series of neutral cyclometalated iridium(III) complexes bearing substituted N-heterocyclic carbene (NHC) ancillary ligands ((C∧N)2Ir(R-NHC), where C∧N and NHC refer to the cyclometalating ligand benzo[h]quinoline and 1-phenylbenzimidazole, respectively) are reported. The NHC ligands were substituted with electron-withdrawing or -donating groups on C4' of the phenyl ring (R = NO2 (Ir1), CN (Ir2), H (Ir3), OCH3 (Ir4), N(CH3)2 (Ir5)) or C5 of the benzimidazole ring (R = NO2 (Ir6), N(CH3)2 (Ir7)). The configuration of Ir1 was confirmed by a single-crystal X-ray diffraction analysis. The ground- and excited-state properties of Ir1-Ir7 were investigated by both spectroscopic methods and time-dependent density functional theory (TDDFT) calculations. All complexes possessed moderately strong structureless absorption bands at ca. 440 nm that originated from the C∧N ligand based 1π,π*/1CT (charge transfer)/1d,d transitions and very weak spin-forbidden 3MLCT (metal-to-ligand charge transfer)/3LLCT (ligand-to-ligand charge transfer) transitions beyond 500 nm. Electron-withdrawing substituents caused a slight blue shift of the 1π,π*/1CT/1d,d band, while electron-donating substituents induced a red shift of this band in comparison to the unsubstituted complex Ir3. Except for the weakly emissive nitro-substituted complexes Ir1 and Ir6 that had much shorter lifetimes (≤160 ns), the other complexes are highly emissive in organic solutions with microsecond lifetimes at ca. 540-550 nm at room temperature, with the emitting states being predominantly assigned to 3π,π*/3MLCT states. Although the effect of the substituents on the emission energy was insignificant, the effects on the emission quantum yields and lifetimes were drastic. All complexes also exhibited broad triplet excited-state absorption at 460-700 nm with similar spectral features, indicating the similar parentage of the lowest triplet excited states. The highly emissive Ir2 was used as a dopant for organic light-emitting diode (OLED) fabrication. The device displayed a yellow emission with a maximum current efficiency (ηc) of 71.29 cd A-1, a maximum luminance (Lmax) of 32747 cd m-2, and a maximum external quantum efficiency (EQE) of 20.6%. These results suggest the potential of utilizing this type of neutral Ir(III) complex as an efficient yellow phosphorescent emitter.

Impact of Benzannulation Site at the Diimine (N

Ten biscyclometalated monocationic Ir(III) complexes were synthesized and studied to elucidate the effects of extending π-conjugation of the diimine ligand (N^N = 2,2'-bipyridine in Ir1, 2-(pyridin-2-yl)quinoline in Ir2, 2-(pyridin-2-yl)[6,7]benzoquinoline in Ir3, 2-(pyridin-2-yl)-[7,8]benzoquinoline in Ir4, phenanthroline in Ir5, benzo[ f][1,10]phenanthroline in Ir6, naphtho[2,3- f][1,10]phenanthroline in Ir7, 2,2'-bisquinoline in Ir8, 3,3'-biisoquinoline in Ir9, and 1,1'-biisoquinoline in Ir10) via benzannulation at 2,2'-bipyridine on the excited-state properties and reverse saturable absorption (RSA) of these complexes. Either a bathochromic or a hypsochromic shift of the charge-transfer absorption band and emission spectrum was observed depending on the benzannulation site at the 2,2'-bipyridine ligand. Benzannulation at the 3,4-/3',4'-position or 5,6-/5',6'-position of 2,2'-bipyridine ligand or at the 6,7-position of the quinoline ring on the N^N ligand caused red-shifted charge-transfer absorption band and emission band for complexes Ir2, Ir8, Ir10 vs Ir1 and Ir3 vs Ir2, while benzannulation at the 4,5-/4',5'-position of 2,2'-bipyridine ligand or at the 7,8-position of the quinoline ring on the N^N ligand induced a blue shift of the charge-transfer absorption and emission bands for complex Ir9 vs Ir1 and Ir4 vs Ir2. However, benzannulation at the 2,2',3,3'-position of 2,2'-bipyridine or 5,6-position of phenanthroline ligand had no impact on the energy of the charge-transfer absorption band and emission band of complexes Ir5-Ir7 compared with those of Ir1. The observed phenomenon was explained by the frontier molecular orbital (FMO) symmetry analysis. Site-dependent benzannulation also impacted the spectral feature and intensity of the triplet transient absorption spectra and lifetimes drastically. Consequently, the RSA strength of these complexes varied with a trend of Ir7 > Ir5 ≈ Ir6 ≈ Ir1 > Ir3 > Ir2 > Ir10 > Ir4 > Ir8 > Ir9 at 532 nm for 4.1 ns laser pulses.

Enhancing the Elasticity of Ultrathin Single-Wall Carbon Nanotube Films with Colloidal Nanocrystals.

Thin bilayers of contrasting nanomaterials are ubiquitous in solution-processed electronic devices and have potential relevance to a number of applications in flexible electronics. Motivated by recent mesoscopic simulations demonstrating synergistic mechanical interactions between thin films of single-wall carbon nanotubes (SWCNTs) and spherical nanocrystal (NC) inclusions, we use a thin-film wrinkling approach to query the compressive mechanics of hybrid nanotube/nanocrystal coatings adhered to soft polymer substrates. Our results show an almost 2-fold enhancement in the Young modulus of a sufficiently thin SWCNT film associated with the presence of a thin interpenetrating overlayer of semiconductor NCs. Mesoscopic distinct-element method simulations further support the experimental findings by showing that the additional noncovalent interfaces introduced by nanocrystals enhance the modulus of the SWCNT network and hinder network wrinkling.

Abrupt Size Partitioning of Multimodal Photoluminescence Relaxation in Monodisperse Silicon Nanocrystals.

Intrinsic constraints on efficient photoluminescence (PL) from smaller alkene-capped silicon nanocrystals (SiNCs) put limits on potential applications, but the root cause of such effects remains elusive. Here, plasma-synthesized colloidal SiNCs separated into monodisperse fractions reveal an abrupt size-dependent partitioning of multilevel PL relaxation, which we study as a function of temperature. Guided by theory and simulation, we explore the potential role of resonant phonon interactions with "minigaps" that emerge in the electronic density of states (DOS) under strong quantum confinement. Such higher-order structures can be very sensitive to SiNC surface chemistry, which we suggest might explain the common implication of surface effects in both the emergence of multimodal PL relaxation and the loss of quantum yield with decreasing nanocrystal size. Our results have potentially profound implications for optimizing the radiative recombination kinetics and quantum yield of smaller ligand-passivated SiNCs.

Interaction of polymer-coated silicon nanocrystals with lipid bilayers and surfactant interfaces.

We use photoluminescence (PL) microscopy to measure the interaction between polyethylene-glycol-coated (PEGylated) silicon nanocrystals (SiNCs) and two model surfaces: lipid bilayers and surfactant interfaces. By characterizing the photostability, transport, and size-dependent emission of the PEGylated nanocrystal clusters, we demonstrate the retention of red PL suitable for detection and tracking with minimal blueshift after a year in an aqueous environment. The predominant interaction measured for both interfaces is short-range repulsion, consistent with the ideal behavior anticipated for PEGylated phospholipid coatings. However, we also observe unanticipated attractive behavior in a small number of scenarios for both interfaces. We attribute this anomaly to defective PEG coverage on a subset of the clusters, suggesting a possible strategy for enhancing cellular uptake by controlling the homogeneity of the PEG corona. In both scenarios, the shape of the apparent potential is modeled through the free or bound diffusion of the clusters near the confining interface.

Effects of race on mortality and use of hospital services in Maryland, 1998.

This study analyzes administrative data from the Maryland Health Services Cost Review Commission to compare differences by race in the use of 17 major procedures performed in hospitals and the corresponding mortality rates. African Americans discharged from Maryland hospitals were less likely than whites to have received most of these procedures while hospitalized. The largest differences were seen for "referral sensitive surgeries" such as percutaneous transluminal coronary angioplasty, coronary artery bypass graft surgery, total knee replacement, and total hip replacement. In contrast, African Americans were found to have substantially higher rates than white patients in the use of four procedures performed in the hospital: amputation of part of the lower limb, surgical debridement, arteriovenostomy, and bilateral orchiectomy. The types of procedures for which African American hospital patients have higher rates raise questions about whether there is a need for more comprehensive and continuous follow-up care with primary care physicians for the underlying health conditions associated with these procedures.

Restricted access to care: the role of race, managed care, and type of insurance.

This article compares African American patients who entered the hospital with the same medical condition-acute myocardial infarction-to similar white patients to assess the relative contributions of insurance type and managed care to the race gap in access to three expensive invasive procedures for treating heart disease: cardiac catheterization, percutaneous transluminal coronary angioplasty (angioplasty or PTCA), and coronary artery bypass surgery (CABG). With data from the state of Maryland, we find that the races differ markedly in their insurance coverage and African Americans have significantly less access to the procedures. Type of insurance and HMO explained little of the difference in access to procedures. Medicare appears to offer as much access to African Americans as commercial providers. We conclude that equalizing access to types of insurance coverage would reduce only a small proportion of the race gap in access to the three procedures.

The impact of fee-for-service and managed care insurance on access to cardiac care in Maryland.

Cardiovascular disease is one of the leading causes of death in the United States. The treatment of acute myocardial infarction (AMI) provides a useful model for studying the impact of fee-for-service and HMO insurance on access to cardiac care. Prior studies provide evidence in support of a disparity in access to cardiac care by insurance type, but no other study has examined the impact of insurance type in a regulated hospital industry. This study is unique because it explores the impact of a regulatory approach that is supplemented by the workings of a competitive market on access to cardiac care for AMI patients. After controlling for age, sex, and race, it was observed that HMO AMI patients were less likely to receive cardiac catheterizations (OR = 0.827 at the 95 percent confidence level) and CABG surgery (OR = 0.852 at 95 percent confidence level) when compared to FFS AMI patients. HMO AMI patients were slightly more likely to receive a PTCA cardiac procedure (OR = 1.067 at the 95 percent confidence level) than FFS AMI patients.

Do nonprofit HMOs eliminate racial disparities in cardiac care?

African-Americans have far less access to treatment for heart disease than similar white Americans. In this article, we explore the sector difference theory hypothesis that treatment provided by a nonprofit Medicaid managed care plan can reduce or even eliminate the race gap. Specifically, we compare the treatment offered to patients in for-profit Medicaid managed care programs to the treatment offered to similar patients in nonprofit Medicaid managed care programs. Data are from the Maryland Health Services Cost Review Commission and cover all patients discharged from hospitals in Maryland during calendar year 1998 with principal diagnoses indicating diseases of the circulatory system (ICD-9-CM codes 390 through 459) or chest pain (ICD-9-CM codes 786.50 through 786.52 and code 786.59). African-Americans were significantly less likely to receive the three treatments of interest, even after controlling for principal diagnosis, blood pressure, co-morbidities, and age. In regard to African-American access to treatment, there were no significant differences between the sectors.

Race and sex differences in the use of cardiac procedures for patients with ischemic heart disease in Maryland.

This study analyzes administrative data from the Maryland Health Services Cost Review Commission to compare differences by race and sex in the use of cardiac procedures performed in hospitals in Maryland. African Americans discharged from Maryland hospitals were less likely than whites to have received cardiac procedures after controlling for age, insurance status, and the number of comorbidities (e.g., hypertension and diabetes). Overall, the general pattern of care suggests that African American women may receive high-technology cardiac treatment significantly less often than all other race and sex categories.

Nonprofit ownership and quality in Medicaid's longterm care program for persons with developmental disabilities.

To assess ownership-related differences in the Intermediate Care Facility Program for persons with Mental Retardation (ICF/MR) Industry, this article analyzes a nationally representative sample of data on Medicaid certified facilities from the Health Care Financing Administration On-line Survey and Certification Reporting System. This study found that nonprofit providers provided a higher level of quality than for-profit facilities when organizational size and facility-mix were controlled. The size and case-mix composition of these facilities were also influenced by nonprofit ownership type. Nonprofit providers offered smaller facilities, on average, and were more likely to enroll heavy case-mix residents than their for-profit counterparts.