Fission Systems for Mars Exploration

Fission systems are used extensively on earth, and 34 such systems have flown in space. The energy density of fission is over 10 million times that of chemical reactions, giving fission the potential to eliminate energy density constraints for many space missions. Potential safety and operational concerns with fission systems are well understood, and strategies exist for affordably developing such systems. By enabling a power-rich environment and highly efficient propulsion, fission systems could enable affordable, sustainable exploration of Mars

Hemoglobin A1c improvements and better diabetes-specific quality of life among participants completing diabetes self-management programs: A nested cohort study

BACKGROUND: Numerous primary care innovations emphasize patient-centered processes of care. Within the context of these innovations, greater understanding is needed of the relationship between improvements in clinical endpoints and patient-centered outcomes. To address this gap, we evaluated the association between glycosylated hemoglobin (HbA(1c)) and diabetes-specific quality of life among patients completing diabetes self-management programs. METHODS: We conducted a retrospective cohort study nested within a randomized comparative effectiveness trial of diabetes self-management interventions in 75 diabetic patients. Multiple linear regression models were developed to examine the relationship between change in HbA(1c) from baseline to one-year follow-up and Diabetes-39 (a diabetes-specific quality of life measure) at one year. RESULTS: HbA(1c) levels improved for the overall cohort from baseline to one-year follow-up (t (74) = 3.09, p = .0029). One-year follow up HbA(1c) was correlated with worse overall quality of life (r = 0.33, p = 0.004). Improvements in HbA(1c) from baseline to one-year follow-up were associated with greater D-39 diabetes control (β = 0.23, p = .04) and D-39 sexual functioning (β = 0.25, p = .03) quality of life subscales. CONCLUSIONS: Improvements in HbA(1c) among participants completing a diabetes self-management program were associated with better diabetes-specific quality of life. Innovations in primary care that engage patients in self-management and improve clinical biomarkers, such as HbA(1c), may also be associated with better quality of life, a key outcome from the patient perspective

One-year outcomes associated with using observation services in triaging patients with nonspecific chest pain

Background: Observation services are provided in greatly variant settings. The aim of this study was to reexamine the effectiveness of observation services compared to inpatient units for patients with nonspecific chest pain.Hypothesis: Patients admitted to observation units have similar outcomes to patients admitted to inpatient wards.Methods: We conducted a claim-based retrospective study for 7549 patients who were admitted to observation and inpatient units. Both models of care were evaluated using the 1-year costs related to chest pain/cardiovascular diseases, and primary and secondary outcomes. Primary outcome was a composite of myocardial infarction, congestive heart failure, stroke, or cardiac arrest, whereas secondary outcomes included revascularization procedures, emergency room revisits, and hospitalization due to cardiovascular diseases.Results: Two-thirds (65.7%, n = 4962) of patients in the sample had observation services, and 34.3% (n = 2587) were admitted to inpatient care. Of the inpatient group, 4.9% experienced a total of 167 primary outcomes, whereas 14.1% experienced a total of 571 secondary outcomes. In comparison, 3.8% of the observation group experienced 238 primary outcomes, and 10.3% experienced 737 secondary outcomes. After adjusting for baseline characteristics using Cox proportional hazard and quantile regression models, no differences between the 2 groups were detected in the 1-year costs of cardiovascular services and primary or secondary outcomes. Patients who had observation services were 79% (95% confidence interval: 1.24-2.58) more likely to have revascularization procedures compared to those admitted to inpatient care.Conclusions: Patients who had observation services had similar outcomes and 1-year costs compared to patients admitted to inpatient wards

Cost-effectiveness of Haemophilus influenzae type b vaccine in Vietnam.

BACKGROUND: With GAVI support, Vietnam introduced Haemophilus influenzae type b (Hib) vaccine in 2010 without evidence on cost-effectiveness. We aimed to analyze the cost-effectiveness of Hib vaccine from societal and governmental perspectives. METHOD: We constructed a decision-tree cohort model to estimate the costs and effectiveness of Hib vaccine versus no Hib vaccine for the 2011 birth cohort. The disease burden was estimated from local epidemiologic data and literature. Vaccine delivery costs were calculated from governmental reports and 2013 vaccine prices. A prospective cost-of-illness study was conducted to estimate treatment costs. The human capital approach was employed to estimate productivity loss. The incremental costs of Hib vaccine were divided by cases, deaths, and disability-adjusted life years (DALY) averted. We used the WHO recommended cost-effectiveness thresholds of an intervention being highly cost-effective if incremental costs per DALY were below GDP per capita. RESULT: From the societal perspective, incremental costs per discounted case, death and DALY averted were US$6252, US$ 26,476 and US$1231, respectively; the break-even vaccine price was US$ 0.69/dose. From the governmental perspective, the results were US$6954, US$ 29,449, and US$1373, respectively; the break-even vaccine price was US$ 0.48/dose. Vietnam's GDP per capita was US$ 1911 in 2013. In deterministic sensitivity analysis, morbidity and mortality parameters were among the most influential factors. In probabilistic sensitivity analysis, Hib vaccine had an 84% and 78% probability to be highly cost-effective from the societal and governmental perspectives, respectively. CONCLUSION: Hib vaccine was highly cost-effective from both societal and governmental perspectives. However, with GAVI support ending in 2016, the government will face a six-fold increase in its vaccine budget at the 2013 vaccine price. The variability of vaccine market prices adds an element of uncertainty. Increased government commitment and improved resource allocation decision making will be necessary to retain Hib vaccine

Revisiting the economic efficiencies of observation units

Background: Recent studies cast doubt about the economic efficiency of observation units (OUs).Objective: We aimed to reexamine the cost savings of OUs compared with inpatient care.Methods: Claims for 15,851 patients who were admitted to inpatient or OUs between January 2009 and December 2012 following emergency room (ER) visits for chest pain were retrospectively examined. The two groups were compared for total cost of episode, length of stay (LOS), and utilization rates of diagnostic procedures, including standard exercise and echocardiography stress tests, myocardial perfusion imaging (MPI), coronary computed tomography angiography (CCTA), and computed tomography (CT) chest scans. Total costs of care and LOS were adjusted for age, gender, risk scores, and comorbidities using quantile regression.Results: More than 37% of the sample was admitted to inpatient units (n = 5,890) vs 62.7% to OUs (n = 9,961). Patients admitted to inpatient units had more comorbidities and longer LOS during their ER visit (median 1.5 adjusted days; 10th percentile = 1, 90th percentile = 3) vs. median 21 adjusted hours for OUs (20, 23). The adjusted median cost of OUs was $5,411 ($4,652, $7,157) vs.$6,946 for inpatient admission ($5,978,$18,683). The estimated adjusted cost saving of OUs was $1,535 (95$1,206, $1,411) compared with inpatient admission. About 37% of patients admitted to OUs stayed longer than 24 hours. Compared with patients admitted to inpatient units, patients in OUs also received more MPI (35.8% vs. 31.5%), CT scans (13.2% vs. 10.4%), standard exercise test (45.6% vs. 33.8%) and echocardiography stress test (8% vs. 3.4%).Conclusion: Despite the increased proportion of patients exceeding the 24-hour LOS and the increased utilization of advanced imaging procedures, OUs are still less costly compared with inpatient admission