Disparities by sex in P2Y 12 inhibitor therapy duration, or differences in the balance of ischaemic-benefit and bleeding-risk clinical outcomes in older women versus comparable men following acute myocardial infarction? A P2Y 12 inhibitor new user retrospective cohort analysis of US Medicare claims data

Objectives To determine if comparable older women and men received different durations of P2Y 12 inhibitor therapy following acute myocardial infarction (AMI) and if therapy duration differences were justified by differences in ischaemic benefits and/or bleeding risks. Design Retrospective cohort. Setting 20% sample of 2007-2015 US Medicare fee-for-service administrative claims data. Participants ≥66-year-old P2Y 12 inhibitor new users following 2008-2013 AMI hospitalisation (N=30 613). Older women compared to older men with similar predicted risks of study outcomes. Primary and secondary outcome measures Primary outcome: P2Y 12 inhibitor duration (modelled as risk of therapy discontinuation). Secondary outcomes: clinical events while on P2Y 12 inhibitor therapy, including (1) death/hospice admission, (2) composite of ischaemic events (AMI/stroke/revascularisation) and (3) hospitalised bleeds. Cause-specific risks and relative risks (RRs) estimated using Aalen-Johansen cumulative incidence curves and bootstrapped 95% CIs. Results 10 486 women matched to 10 486 men with comparable predicted risks of all 4 study outcomes. No difference in treatment discontinuation was observed at 12 months (women 31.2% risk; men 30.9% risk; RR 1.01; 95% CI 0.97 to 1.05), but women were more likely than men to discontinue therapy at 24 months (54.4% and 52.9% risk, respectively; RR 1.03; 95% CI 1.00 to 1.05). Among patients who did not discontinue P2Y 12 inhibitor therapy, women had lower 24-month risks of ischaemic outcomes than men (13.1% and 14.7%, respectively; RR 0.90; 95% CI 0.84 to 0.96), potentially lower 24-month risks of death/hospice admission (5.0% and 5.5%, respectively; RR 0.91; 95% CI 0.82 to 1.02), but women and men both had 2.5% 24-month bleeding risks (RR 0.98; 95% CI 0.82 to 1.14). Conclusions Risks for death/hospice and ischaemic events were lower among women still taking a P2Y 12 inhibitor than comparable men, with no difference in bleeding risks. Shorter P2Y 12 inhibitor durations in older women than comparable men observed between 12 and 24 months post-AMI may reflect a disparity that is not justified by differences in clinical need

Off-diagonal 2-4 damping technology using semi-active resetable devices

Semi-active resetable devices are an emerging and effective method of minimising structural degradation due to environmental loads. Of particular importance in implementing supplemental damping, such as resetable devices, is the ability to retrofit existing structures. However, supplemental damping also tends to increase base shear demand, limiting practical gains. The use of a two-chamber resetable device enables a control law to be used that adds damping only into quadrants 2 and 4 of the force-deflection plot, adding damping forces on the opposing diagonals to the structural force. Thus, base shear can be reduced, creating significant potential for retrofit applications. The impact of off-diagonal 2-4 damping on the displacement structural response, structural force and total base shear is investigated through spectral analysis. The 2-4 control law is shown to be the only law that can reduce the structural force as well as the total base shear for a structure; a unique result. Off-diagonal damping equal to 100% additional stiffness reduced both the structural force and total base-shear by 20-35%. Therefore, semi-active enabled off-diagonal damping could be incorporated into large scale retrofit applications where present passive approaches have significant limitation

Accuracy of the electronic health record’s problem list in describing multimorbidity in patients with heart failure in the emergency department

Patients with heart failure (HF) often suffer from multimorbidity. Rapid assessment of multimorbidity is important for minimizing the risk of harmful drug-disease and drug-drug interactions. We assessed the accuracy of using the electronic health record (EHR) problem list to identify comorbid conditions among patients with chronic HF in the emergency department (ED). A retrospective chart review study was performed on a random sample of 200 patients age ≥65 years with a diagnosis of HF presenting to an academic ED in 2019. We assessed participant chronic conditions using: (1) structured chart review (gold standard) and (2) an EHR-based algorithm using the problem list. Chronic conditions were classified into 37 disease domains using the Agency for Healthcare Research Quality’s Elixhauser Comorbidity Software. For each disease domain, we report the sensitivity, specificity, positive predictive value, and negative predictive of using an EHR-based algorithm. We calculated the intra-class correlation coefficient (ICC) to assess overall agreement on Elixhauser domain count between chart review and problem list. Patients with HF had a mean of 5.4 chronic conditions (SD 2.1) in the chart review and a mean of 4.1 chronic conditions (SD 2.1) in the EHR-based problem list. The five most prevalent domains were uncomplicated hypertension (90%), obesity (42%), chronic pulmonary disease (38%), deficiency anemias (33%), and diabetes with chronic complications (30.5%). The positive predictive value and negative predictive value of using the EHR-based problem list was greater than 90% for 24/37 and 32/37 disease domains, respectively. The EHR-based problem list correctly identified 3.7 domains per patient and misclassified 2.0 domains per patient. Overall, the ICC in comparing Elixhauser domain count was 0.77 (95% CI: 0.71-0.82). The EHR-based problem list captures multimorbidity with moderate-to-good accuracy in patient with HF in the ED

Re-Shaping Hysteretic Behaviour - Spectral Analysis and Design Equations for Semi-Active Structures

Semi-active dampers offer significant capability to reduce dynamic wind and seismic structural response. A novel resetable device with independent valve control laws that enables semi-active re-shaping of the overall structural hysteretic behaviour has been recently developed, and a one-fifth scale prototype experimentally validated. This research statistically analyses three methods of re-shaping structural hysteretic dynamics in a performance-based seismic design context. Displacement, structural force, and total base-shear response reduction factor spectra are obtained for suites of ground motions from the SAC project. Results indicate that the reduction factors are suite invariant. Resisting all motion adds damping in all four quadrants and showed 40-60% reductions in the structural force and displacement at the cost of a 20-60% increase in total base-shear. Resisting only motion away from equilibrium adds damping in quadrants 1 and 3, and provides reductions of 20-40%, with a 20-50% increase in total base-shear. However, only resisting motion towards equilibrium adds damping in quadrants 2 and 4 only, for which the structural responses and total base-shear are reduced 20-40%. The spectral analysis results are used to create empirical reduction factor equations suitable for use in performance based design methods, creating an avenue for designing these devices into structural applications. Overall, the reductions in both response and base-shear indicate the potential appeal of this semi-active hysteresis sculpting approach for seismic retrofit applications - largely due to the reduction of the structural force and overturning demands on the foundation system

Studies of the Extreme Quantum Limit of 2d Hole Systems

Contains fulltext : 29376.pdf (publisher's version ) (Open Access

Observation of the transition to an insulating state consistent with a Wigner solid in a high-density 2D hole gas

Contains fulltext : 112794.pdf (publisher's version ) (Open Access