720 research outputs found
Numerical simulation of a supercritical inlet flow
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76033/1/AIAA-1985-1214-300.pd
Bark and wood properties of pulpwood species as related to separation and segregation of chip/bark mixtures. Project 3212, report two : a progress report to members of Group Project 3212
"February 14, 1975.""Members of Project 3212: Abitibi Paper Company, Ltd., Blandin Paper Company, the Procter and Gamble Company, Scott Paper Company, Weyerhaeuser Company.""The Institute of Paper Chemistry, Marianne L. Harder, research assistant, John D. Hankey, research associate, Dean W. Einspahr, senior research associate, and John W. Swanson, director, Division of Natural Materials and Systems.
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Patient-Reported Satisfaction and Study Drug Discontinuation: Post-Hoc Analysis of Findings from ROCKET AF.
IntroductionPatient-reported outcomes (PROs) and satisfaction endpoints are increasingly important in clinical trials and may be associated with treatment adherence. In this post hoc substudy from ROCKET AF, we examined whether patient-reported satisfaction was associated with study drug discontinuation.MethodsROCKET AF (nâ=â14,264) compared rivaroxaban with warfarin for prevention of stroke and systemic embolism in patients with atrial fibrillation. We analyzed treatment satisfaction scores: the Anti-Clot Treatment Scale (ACTS) and Treatment Satisfaction Questionnaire for Medication version II (TSQM II). We compared satisfaction with study drug between the two treatment arms, and examined the association between satisfaction and patient-driven study drug discontinuation (stopping study drug due to withdrawal of consent, noncompliance, or loss to follow-up).ResultsA total of 1577 (11%) patients participated in the Patient Satisfaction substudy; 1181 (8.3%) completed both the ACTS and TSQM II 4Â weeks after starting study drug. Patients receiving rivaroxaban did not experience significant differences in satisfaction compared with those receiving warfarin. During a median follow-up of 1.6Â years, 448 premature study drug discontinuations occurred (213 rivaroxaban group; 235 warfarin group), of which 116 (26%) were patient-driven (52 [24%] rivaroxaban group; 64 [27%] warfarin group). No significant differences were observed between satisfaction level and rates of patient-driven study drug discontinuation.ConclusionsStudy drug satisfaction did not predict rate of study drug discontinuation. No significant difference was observed between satisfaction with warfarin and rivaroxaban, as expected given the double-blind trial design. Although these results are negative, the importance of PRO data will only increase, and these analyses may inform future studies that explore the relationship between drug-satisfaction PROs, adherence, and clinical outcomes. CLINICALTRIALS.GOV: NCT00403767.FundingThe ROCKET AF trial was funded by Johnson & Johnson and Bayer
Safety and Efficacy of Rivaroxaban in Patients With Cardiac Implantable Electronic Devices:Observations From the ROCKET AF Trial
Background: Although implantation of cardiac implantable electronic devices (CIEDs) in patients receiving warfarin is well studied, limited data are available on the use of oral factor Xa inhibitors in this setting. Methods and Results: Using data from Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF) (n=14 264), we compared baseline characteristics and clinical outcomes in patients with atrial fibrillation randomized to rivaroxaban versus warfarin who did and did not undergo CIED implantation or revision. In this postâhoc, postrandomization, onâtreatment analysis, only the first intervention per patient was analyzed. During a median followâup of 2.2 years, 453 patients (242 rivaroxaban group; 211 warfarin group) underwent de novo CIED implantation (64.2%) or revision procedures (35.8%). Patients who received CIEDs were older, more likely to be male, and more likely to have past myocardial infarction, but had similar stroke risk compared to patients who did not receive CIEDs. Most patients who received a device had study drug interrupted for the procedure and did not receive bridging anticoagulation. During the 30âday postprocedural period, 11 patients (4.55%) in the rivaroxaban group experienced bleeding complications compared with 15 (7.13%) in the warfarin group. Thromboembolic complications occurred in 3 patients (1.26%) in the rivaroxaban group and 1 (0.48%) in the warfarin group. Event rates were too low for formal hypothesis testing. Conclusions: Bleeding and thromboembolic events were low in both rivaroxabanâ and warfarinâtreated patients. Periprocedural use of oral factor Xa inhibitors in CIED implantation requires further study in prospective, randomized trials. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT00403767
Outcomes After Cardioversion and Atrial Fibrillation Ablation in Patients Treated With Rivaroxaban and Warfarin in the ROCKET AF Trial
ObjectivesThis study sought to investigate the outcomes following cardioversion or catheter ablation in patients with atrial fibrillation (AF) treated with warfarin or rivaroxaban.BackgroundThere are limited data on outcomes following cardioversion or catheter ablation in AF patients treated with factor Xa inhibitors.MethodsWe compared the incidence of electrical cardioversion (ECV), pharmacologic cardioversion (PCV), or AF ablation and subsequent outcomes in patients in a post hoc analysis of the ROCKET AF (Efficacy and Safety Study of Rivaroxaban With Warfarin for the Prevention of Stroke and Non-Central Nervous System Systemic Embolism in Patients With Non-Valvular Atrial Fibrillation) trial.ResultsOver a median follow-up of 2.1 years, 143 patients underwent ECV, 142 underwent PCV, and 79 underwent catheter ablation. The overall incidence of ECV, PCV, or AF ablation was 1.45 per 100 patient-years (n = 321; 1.44 [n = 161] in the warfarin arm, 1.46 [n = 160] in the rivaroxaban arm). The crude rates of stroke and death increased in the first 30 days after cardioversion or ablation. After adjustment for baseline differences, the long-term incidence of stroke or systemic embolism (hazard ratio [HR]: 1.38; 95% confidence interval [CI]: 0.61 to 3.11), cardiovascular death (HR: 1.57; 95% CI: 0.69 to 3.55), and death from all causes (HR: 1.75; 95% CI: 0.90 to 3.42) were not different before and after cardioversion or AF ablation. Hospitalization increased after cardioversion or AF ablation (HR: 2.01; 95% CI: 1.51 to 2.68), but there was no evidence of a differential effect by randomized treatment (p value for interaction = 0.58). The incidence of stroke or systemic embolism (1.88% vs. 1.86%) and death (1.88% vs. 3.73%) were similar in the rivaroxaban-treated and warfarin-treated groups.ConclusionsDespite an increase in hospitalization, there were no differences in long-term stroke rates or survival following cardioversion or AF ablation. Outcomes were similar in patients treated with rivaroxaban or warfarin. (An Efficacy and Safety Study of Rivaroxaban With Warfarin for the Prevention of Stroke and Non-Central Nervous System Systemic Embolism in Patients With Non-Valvular Atrial Fibrillation [ROCKET AF]; NCT00403767
Hospitalizations in patients with atrial fibrillation:an analysis from ROCKET AF
AIMS: The high costs associated with treatment for atrial fibrillation (AF) are primarily due to hospital care, but there are limited data to understand the reasons for and predictors of hospitalization in patients with AF. METHODS AND RESULTS: The ROCKET AF trial compared rivaroxaban with warfarin for stroke prophylaxis in AF. We described the frequency of and reasons for hospitalization during study follow-up and utilized Cox proportional hazards models to assess for baseline characteristics associated with all-cause hospitalization. Of 14 171 patients, 14% were hospitalized at least once. Of 2614 total hospitalizations, 41% were cardiovascular including 4% for AF; of the remaining, 12% were for bleeding. Compared with patients not hospitalized, hospitalized patients were older (74 vs. 72 years), and more frequently had diabetes (46 vs. 39%), prior MI (23 vs. 16%), and paroxysmal AF (19 vs. 17%), but less frequently had prior transient ischaemic attack/stroke (49 vs. 56%). After multivariable adjustment, lung disease [hazard ratio (HR) 1.46, 95% confidence interval (CI) 1.29â1.66], diabetes [1.22, (1.11â1.34)], prior MI [1.27, (1.13â1.42)], and renal dysfunction [HR 1.07 per 5 unit GFR < 65 mL/min, (1.04â1.10)] were associated with increased hospitalization risk. Treatment assignment was not associated with differential rates of hospitalization. CONCLUSION: Nearly 1 in 7 of the moderate-to-high-risk patients with AF enrolled in this trial was hospitalized within 2 years, and both AF and bleeding were rare causes of hospitalization. Further research is needed to determine whether care pathways directed at comorbid conditions among AF patients could reduce the need for and costs associated with hospitalization
Impact of global geographic region on time in therapeutic range on warfarin anticoagulant therapy:data from the ROCKET AF clinical trial
Background: Vitamin K antagonist (VKA) therapy remains the most common method of stroke prevention in patients with atrial fibrillation. Time in therapeutic range (TTR) is a widely cited measure of the quality of VKA therapy. We sought to identify factors associated with TTR in a large, international clinical trial. Methods and Results: TTR (international normalized ratio [INR] 2.0 to 3.0) was determined using standard linear interpolation in patients randomized to warfarin in the ROCKET AF trial. Factors associated with TTR at the individual patient level (iâTTR) were determined via multivariable linear regression. Among 6983 patients taking warfarin, recruited from 45 countries grouped into 7 regions, the mean iâTTR was 55.2% (SD 21.3%) and the median iâTTR was 57.9% (interquartile range 43.0% to 70.6%). The mean time with INR 3 was 15.7%. While multiple clinical features were associated with iâTTR, dominant determinants were previous warfarin use (mean iâTTR of 61.1% for warfarinâexperienced versus 47.4% in VKAânaĂŻve patients) and geographic region where patients were managed (mean iâTTR varied from 64.1% to 35.9%). These effects persisted in multivariable analysis. Regions with the lowest iâTTRs had INR distributions shifted toward lower INR values and had longer interâINR test intervals. Conclusions: Independent of patient clinical features, the regional location of medical care is a dominant determinant of variation in iâTTR in global studies of warfarin. Regional differences in mean iâTTR are heavily influenced by subtherapeutic INR values and are associated with reduced frequency of INR testing
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Relationship Between Time in Therapeutic Range and Comparative Treatment Effect of Rivaroxaban and Warfarin: Results From the ROCKET AF Trial
Background: Time in therapeutic range (TTR) is a standard quality measure of the use of warfarin. We assessed the relative effects of rivaroxaban versus warfarin at the level of trial center TTR (cTTR) since such analysis preserves randomized comparisons. Methods and Results: TTR was calculated using the Rosendaal method, without exclusion of international normalized ratio (INR) values performed during warfarin initiation. Measurements during warfarin interruptions >7 days were excluded. INRs were performed via standardized fingerâstick pointâofâcare devices at least every 4 weeks. The primary efficacy endpoint (stroke or nonâcentral nervous system embolism) was examined by quartiles of cTTR and by cTTR as a continuous function. Centers with the highest cTTRs by quartile had lowerârisk patients as reflected by lower CHADS2 scores (P<0.0001) and a lower prevalence of prior stroke or transient ischemic attack (P<0.0001). Sites with higher cTTR were predominantly from North America and Western Europe. The treatment effect of rivaroxaban versus warfarin on the primary endpoint was consistent across a wide range of cTTRs (P value for interaction=0.71). The hazard of major and nonâmajor clinically relevant bleeding increased with cTTR (P for interaction=0.001), however, the estimated reduction by rivaroxaban compared with warfarin in the hazard of intracranial hemorrhage was preserved across a wide range of threshold cTTR values. Conclusions: The treatment effect of rivaroxaban compared with warfarin for the prevention of stroke and systemic embolism is consistent regardless of cTTR
Impact of socioeconomic status on cancer incidence and stage at diagnosis: selected findings from the surveillance, epidemiology, and end results: National Longitudinal Mortality Study
BACKGROUND: Population-based cancer registry data from the Surveillance, Epidemiology, and End Results (SEER) Program at the National Cancer Institute (NCI) are mainly based on medical records and administrative information. Individual-level socioeconomic data are not routinely reported by cancer registries in the United States because they are not available in patient hospital records. The U.S. representative National Longitudinal Mortality Study (NLMS) data provide self-reported, detailed demographic and socioeconomic data from the Social and Economic Supplement to the Census Bureau's Current Population Survey (CPS). In 1999, the NCI initiated the SEER-NLMS study, linking the population-based SEER cancer registry data to NLMS data. The SEER-NLMS data provide a new unique research resource that is valuable for health disparity research on cancer burden. We describe the design, methods, and limitations of this data set. We also present findings on cancer-related health disparities according to individual-level socioeconomic status (SES) and demographic characteristics for all cancers combined and for cancers of the lung, breast, prostate, cervix, and melanoma. METHODS: Records of cancer patients diagnosed in 1973â2001 when residing 1 of 11 SEER registries were linked with 26 NLMS cohorts. The total number of SEER matched cancer patients that were also members of an NLMS cohort was 26,844. Of these 26,844 matched patients, 11,464 were included in the incidence analyses and 15,357 in the late-stage diagnosis analyses. Matched patients (used in the incidence analyses) and unmatched patients were compared by age group, sex, race, ethnicity, residence area, year of diagnosis, and cancer anatomic site. Cohort-based age-adjusted cancer incidence rates were computed. The impact of socioeconomic status on cancer incidence and stage of diagnosis was evaluated. RESULTS: Men and women with less than a high school education had elevated lung cancer rate ratios of 3.01 and 2.02, respectively, relative to their college educated counterparts. Those with family annual incomes less than 50,000 or higher. Lower income was also associated with a statistically significantly increased risk of distant-stage breast cancer among women and distant-stage prostate cancer among men. CONCLUSIONS: Socioeconomic patterns in incidence varied for specific cancers, while such patterns for stage were generally consistent across cancers, with late-stage diagnoses being associated with lower SES. These findings illustrate the potential for analyzing disparities in cancer outcomes according to a variety of individual-level socioeconomic, demographic, and health care characteristics, as well as by area measures available in the linked database
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