ABSTRACT
BACKGROUND: The State of Louisiana spends the most on Medicare beneficiaries per capita, but reports greater disparities in health status and death rates than other states. This project sought to investigate the associations between healthcare intensity, healthcare spending, and mortality in Louisiana. METHODS: We used a 100% sample of 2014 Medicare claims data with beneficiaries assigned to hospital referral regions in Louisiana using small area analysis. We used simple and multivariable linear regression modelling to evaluate associations between healthcare intensity, healthcare spending rates, and mortality rates. We adjusted for age, sex, race, and population health risk factors. RESULTS: We found no statistically significant associations between our measured variables when adjusted for age, sex, and race. These results were consistent after further adjusting mortality for population health risk factors. CONCLUSIONS: To our knowledge, no prior studies have investigated the associations between healthcare intensity, healthcare spending, and mortality in Louisiana. Our findings suggest that increased healthcare spending in Louisiana may not improve survival. Identifying more granular aspects of healthcare contributing to spending patterns in Louisiana may provide targets for future quality improvement work.
Subject(s)
Health Expenditures/statistics & numerical data , Medicare/economics , Medicare/statistics & numerical data , Aged , Aged, 80 and over , Female , Health Services Research , Health Status , Humans , Linear Models , Louisiana , Male , Risk Factors , United States/epidemiologyABSTRACT
Photothermal release of oligonucleotides from the surface of plasmonic nanoparticles represents a promising platform for spatiotemporal controlled drug delivery. Here we demonstrate the use of novel gold-silver-gold core-shell-shell (CSS) nanoparticles to study the photothermal cleaving and release of micro-RNA (miRNA) mimics or small interfering RNA (siRNA) under nearinfrared (NIR) irradiation. The furan-maleimide-based Diels-Alder adduct cleaves thermally above 60 °C and is used to bind siRNA to the colloidal nanoparticle surface in water. We investigate the photothermal cleaving kinetics of siRNA under different NIR laser powers using surface-sensitive time-dependent second-harmonic generation (SHG) spectroscopy. The photothermal release of siRNA from the surface of CSS nanoparticles is significantly higher than that from the surface of gold nanoparticles (GNPs) under similar experimental conditions. These results demonstrate that plasmonic CSS nanoparticles with photothermal cleaving linkers have important potential applications for nanoparticle-based NIR-mediated drug-delivery systems.
ABSTRACT
The photocleaving dynamics of colloidal microRNA-functionalized nanoparticles are studied using time-dependent second harmonic generation (SHG) measurements. Model drug-delivery systems composed of oligonucleotides attached to either silver nanoparticles or polystyrene nanoparticles using a nitrobenzyl photocleavable linker are prepared and characterized. The photoactivated controlled release is observed to be most efficient on resonance at 365 nm irradiation, with pseudo-first-order rate constants that are linearly proportional to irradiation powers. Additionally, silver nanoparticles show a 6-fold plasmon enhancement in photocleaving efficiency over corresponding polystyrene nanoparticle rates, while our previous measurements on gold nanoparticles show a 2-fold plasmon enhancement compared to polystyrene nanoparticles. Characterizations including extinction spectroscopy, electrophoretic mobility, and fluorimetry measurements confirm the analysis from the SHG results. The real-time SHG measurements are shown to be a highly sensitive method for investigating plasmon-enhanced photocleaving dynamics in model drug delivery systems.
