Factors associated with low-acuity hospital admissions in a public safety-net setting: a cross-sectional study.

BACKGROUND: Given system-level focus on avoidance of unnecessary hospitalizations, better understanding admission decision-making is of utility. Our study sought to identify factors associated with hospital admission versus discharge from the Emergency Department (ED) for a population of patients who were assessed as having low medical acuity at time of decision. METHODS: Using an institutional database, we identified ED admission requests received from March 1, 2018 to Feb 28, 2019 that were assessed by a physician at the time of request as potentially inappropriate based on lack of medical acuity. Focused chart review was performed to extract data related to patient demographics, socioeconomic information, measures of illness, and system-level factors such as previous healthcare utilization and day/time of presentation. A binary logistic regression model was constructed to correlate patient and system factors with disposition outcome of admission to the hospital versus discharge from the ED. Physician-reported contributors to admission decision-making and chief complaint/reason for admission were summarized. RESULTS: A total of 349 (77.2%) of 452 calls resulted in admission to the hospital and 103 (22.8%) resulted in discharge from the ED. Predictors of admission included age over 65 (OR 3.5 [95%CI 1.1-11.6], p = 0.039), homelessness (OR 3.3 [95% CI 1.7-6.4], p=0.001), and night/weekend presentation (OR 2.0 [95%CI 1.1-3.5], p = 0.020). The most common contributing factors to the decision to admit reported by the responding physician included: lack of outpatient social support (35.8% of admissions), homelessness (33.0% of admissions), and substance use disorder (23.5% of admissions). CONCLUSIONS: Physician medical decision-making regarding the need for hospitalization incorporates consideration of individual patient characteristics, social setting, and system-level barriers. Interventions aimed at reducing unnecessary hospitalizations, especially those involving patients with low medical acuity, should focus on underlying unmet needs and involve a broad set of perspectives.

Modeling Equilibrium Binding at Quantum Dot Surfaces Using Cyclic Voltammetry.

Cyclic voltammetry is demonstrated as a useful method to model equilibrium binding between quantum dots and redox active small molecules. Specifically, the interaction of a library of ferrocene derivatives with CdSe quantum dots is examined. For the strongly interacting systems, ferrocene carboxylic acid (FcCOOH) and ferrocene hexanethiol (Fc-hexSH), the binding equilibria can be quantitatively deduced by modeling the cyclic voltammetry data. This modeling allows extraction of the diffusion coefficients, equilibrium constants associated with both the reduced and oxidized species, and forward and reverse rates associated with binding for both the reduced and oxidized species. Taken together these data give direct insight into the binding of small molecules to quantum-dot surfaces as a function of oxidation state, critical information for the design of quantum dots as photoredox catalysts and charge transfer mediators.