The age of Wolfe Creek meteorite crater (Kandimalal), Western Australia

Wolfe Creek crater lies in northwestern Australia at the edge of the Great Sandy Desert. Together with Meteor Crater, it is one of the two largest craters on Earth from which meteorite fragments have been recovered. The age of the impact is poorly constrained and unpublished data places the event at about 300,000 years ago. In comparison, Meteor Crater is well constrained by exposure dating. In this paper, we present new ages for Wolfe Creek Crater from exposure dating using the cosmogenic nuclides 10Be and 26Al, together with optically stimulated luminescence ages (OSL) on sand from a site created by the impact. We also present a new topographic survey of the crater using photogrammetry. The exposure ages range from ~86 to 128 ka. The OSL ages indicate that the age of the impact is most likely to be ~120 ka with a maximum age of 137 ka. Considering the geomorphic setting, the most likely age of the crater is 120 ± 9 ka. Last, we review the age of Meteor Crater in Arizona. Changes in production rates and scaling factors since the original dating work revise the impact age to 61.1 ± 4.8 ka, or ~20% older than previously reported

Impact of ASA score misclassification on NSQIP predicted mortality: a retrospective analysis

Abstract Background The ASA physical classification score has a major impact on the observed/expected (O/E) mortality ratio in the NSQIP General Vascular Mortality Model. The difference in predicted mortality is greatest between ASAs 3 and 4. We hypothesized under-classified ASA scores significantly affect the O/E mortality. Methods We conducted a retrospective review of NSQIP essential surgery cases from January 2014 to December 2014 (n = 1264) with mortality sub-analysis (n = 33) at our institution. We recorded transfer and emergency status and independently calculated the ASA score for mortalities using published definitions. A random sample of 50 survivors and 10 emergency survivors were reviewed and ASA recalculated. We performed statistical modeling to simulate the effects of ASA misclassifications. Statistical analysis was performed using JMP 10 and SAS 9.4. Results ASA was under-classified in 18.2% of mortalities, most commonly ASAs 3 and 4. Sixteen percent of ASA 3 survivors were misclassified, including 60% in the emergency subgroup (p < 0.05 vs. elective cases). Patients transferred from other institutions were more likely to be emergency cases than non-transferred patients (43.5 vs. 7.84%, p < 0.05). Transferred patients had a higher proportion of ASAs 3–5 vs. ASAs 1–2 compared with non-transfers (84.38 vs. 49.76%, p < 0.05) Simulation data showed ASA misclassification underestimated predicted mortality by 2.5 deaths on average. Conclusion ASA misclassification significantly impacts O/E mortality. With accurate ASA classification, observed mortality would not have exceeded expected mortality in our institution. Education regarding the impact of ASA scoring is critical to ensure accurate O/E mortality data at hospitals using NSQIP to assess surgical quality

Patient preferences for treatment of acute bacterial skin and skin structure infections in the emergency department

Abstract Background Limited research has assessed patient preferences for treatment disposition and antibiotic therapy of acute bacterial skin and skin structure infection (ABSSSI) in the emergency department (ED). Understanding patient preference for the treatment of ABSSSI may influence treatment selection and improve satisfaction. Methods A survey was conducted across 6 US hospital EDs. Patients with ABSSSI completed a baseline survey assessing preferences for antibiotic therapy (intravenous versus oral) and treatment location. A follow-up survey was conducted within 30–40 days after ED discharge to reassess preferences and determine satisfaction with care. Results A total of 94 patients completed both baseline and follow-up surveys. Sixty (63.8%) participants had a history of ABSSSI, and 69 (73.4%) were admitted to the hospital. Treatment at home was the most common preference reported on baseline and follow-up surveys. Patients with higher education were 82.2% less likely to prefer treatment in the hospital. Single dose intravenous therapy was the most commonly preferred antibiotic regimen on baseline and follow-up surveys (39.8 and 19.1%, respectively). Median satisfaction scores for care in the ED, hospital, home, and with overall antibiotic therapy were all 8 out of a maximum of 10. Conclusions In these patients, the most common preference was for outpatient care and single dose intravenous antibiotics. Patient characteristics including higher education, younger age, and current employment were associated with these preferences. Opportunities exist for improving ABSSSI care and satisfaction rates by engaging patients and offering multiple treatment choices