A system to build distributed multivariate models and manage disparate data sharing policies: implementation in the scalable national network for effectiveness research

Background Centralized and federated models for sharing data in research networks currently exist. To build multivariate data analysis for centralized networks, transfer of patient-level data to a central computation resource is necessary. The authors implemented distributed multivariate models for federated networks in which patient-level data is kept at each site and data exchange policies are managed in a study-centric manner.Objective The objective was to implement infrastructure that supports the functionality of some existing research networks (e.g., cohort discovery, workflow management, and estimation of multivariate analytic models on centralized data) while adding additional important new features, such as algorithms for distributed iterative multivariate models, a graphical interface for multivariate model specification, synchronous and asynchronous response to network queries, investigator-initiated studies, and study-based control of staff, protocols, and data sharing policies.Materials and Methods Based on the requirements gathered from statisticians, administrators, and investigators from multiple institutions, the authors developed infrastructure and tools to support multisite comparative effectiveness studies using web services for multivariate statistical estimation in the SCANNER federated network.Results The authors implemented massively parallel (map-reduce) computation methods and a new policy management system to enable each study initiated by network participants to define the ways in which data may be processed, managed, queried, and shared. The authors illustrated the use of these systems among institutions with highly different policies and operating under different state laws.Discussion and Conclusion Federated research networks need not limit distributed query functionality to count queries, cohort discovery, or independently estimated analytic models. Multivariate analyses can be efficiently and securely conducted without patient-level data transport, allowing institutions with strict local data storage requirements to participate in sophisticated analyses based on federated research networks.     

Impact of Early Invasive Approach on Outcomes of Patients With Acute Coronary Syndrome and Baseline Anemia: Analysis From the ACSIS Registry

Background

Anemia in patients with acute coronary syndromes (ACS) is strongly related to the increased risk of bleeding and mortality. Whether benefit of early invasive strategy exceeds the risk of bleeding in these patients is unknown.

Aim

To assess impact of early coronary angiography on outcomes of patients with ACS and baseline anemia.

Methods and Results

Biennial Israeli ACS registry (ACSIS) prospectively collects data from all 26 public hospitals. The endpoints included rates of in‐hospital major bleeding, as well as 30‐day and 1‐year mortality. Anemia at baseline was present in 1,464 of 5,600 patients with ACS (26.1%). Coronary angiography within index hospitalization was performed less frequently in patients with anemia (76.6% vs. 90.8%, P < 0.001). Non‐performance of coronary angiography was associated with older age and higher prevalence of comorbidities. Among patients with anemia who underwent coronary angiography, the majority (95.5%) had obstructive coronary disease, of whom 77.8% were triaged to revascularization. Performance of coronary angiography was associated with significantly lower (P < 0.0001) rates of mortality at 30 days (5.7% vs. 15.6%) and at 1 year (11.9% vs. 34.1%). Major bleeding occurred with similar incidence in groups with and without coronary angiography (3.1% vs. 3.8%, respectively; P = 0.54). By multivariable analysis, performance of coronary angiography was an independent predictor of lower 1‐year mortality (hazard ratio [95%CI] = 0.30 [0.21, 0.44].

Conclusion

In the setting of ACS, despite the presence of baseline anemia, early coronary angiography with subsequent revascularization, when indicated, was associated with improved clinical outcomes including 1‐year mortality without significant increase in rates of major bleeding.

     

Evaluation of the Binax NOW ICT test versus polymerase chain reaction and microscopy for the detection of malaria in returned travelers

Microscopic detection of Plasmodium species has been the reference standard for the diagnosis of malaria for more than a century. However, maintaining a sufficient level of expertise in microscopic diagnosis can be challenging, particularly in non-endemic countries. The objective of this study was to compare a new rapid malaria diagnostic device (NOW ICT Malaria Test; Binax, Inc., Portland, ME) to polymerase chain reaction (PCR) and expert microscopy for the diagnosis of malaria in 256 febrile returned travelers. Compared with PCR, the NOW ICT test showed a sensitivity of 94% for the detection of P. falciparum malaria (96% for pure P. falciparum infection) and 84% for non-P. falciparum infections (87% for pure P. vivax infections and 62% for pure P. ovale and P. malariae infections), with an overall specificity of 99%. The Binax NOW ICT may represent a useful adjunct for the diagnosis of P. falciparum and P. vivax malaria in febrile returned travelers.     

Research on the quality of life of lung transplant candidates and recipients: an integrative review

Although lung transplantation is one of the most rapidly growing areas of solid organ transplantation, there has been little research on the quality of life of lung transplant candidates or recipients. This review critiques and synthesizes the quality-of-life reports concerning these patients that have been published between January 1980 and January 1999. The purposes of this review of the literature were to (1) examine both the conceptual and operational definitions of quality of life used; (2) identify and list the instruments used to measure quality of life; (3) investigate methodologic issues; and (4) determine the state-of-the-art of research in this area. On the basis of this review, suggestions are made for future studies.     

Interactions between angiotensin II and phenylephrine on isolated rat renal arteries and veins

It is know that not only decreased blood flow to the kidney but also obstruction of renal outflow may, in some instances, be a cause of hypertension. In this view were compared angiotensin (Ang) II responses and investigated interactions between Ang II and phenylephrine (Phe) on renal vessels. Studies were performed on renal artery and vein rings without endothelium obtained from young (4 months) and old (12 month of age) male Wistar rats. As compared with control contractions (40 microM KC1) there are no differences between renal artery and veins on Phe- or Ang II-induced contractions. Phe -induced contractions after 1 microM Ang II pretreatment were higher on renal veins than arteries. Ang II administered after 1 microM Phe could additional increase Phe-induced contractions only on renal veins. On the other hand, these differences between renal arteries and veins responses were significantly higher on rings obtained from old as compared those from young rats. These age-dependent differences between renal artery and vein reactivity can be a possible cause of input-output renal blood flow unbalance and might become important in some pathological states which associate sympathetic activation with hyperreninemia.     

A rare case of partial trisomy 8q24.12-q24.3 and partial monosomy of 8q24.3: Prenatal diagnosis and clinical findings

Objective

We describe a rare case of “pure” 8q duplication diagnosed prenatally by conventional karyotyping, that was further characterized by array comparative genomic hybridization (aCGH).

Real-time PCR assay for rapid detection and analysis of PfCRT haplotypes of chloroquine-resistant Plasmodium falciparum isolates from India

Chloroquine-resistant Plasmodium falciparum (CRPF) malaria isolates in Southeast Asia and sub-Saharan Africa share the same Plasmodium falciparum chloroquine resistance transporter (PfCRT) haplotype (CVIET; amino acids 72 to 76). It is believed that CRPF malaria emerged in Southeast Asia and spread to sub-Saharan Africa via the Indian subcontinent. Based on this assumption, we hypothesized that CRPF isolates in India should possess the same drug resistance haplotype (PfCRT haplotype CVIET) as P. falciparum isolates in Southeast Asia and Africa and that the prevalence of CRPF may be higher and more widespread in India than appreciated. To test this postulate, we utilized a standardized real-time PCR assay to assess the prevalence and distribution of PfCRT haplotypes in P. falciparum isolates (n = 406) collected from Western, Central, and Eastern states in India and compared them to isolates from South America and Africa. Based on the proportion of isolates possessing the molecular marker K76T, the prevalence of chloroquine resistance was high in all five regions of India studied (91%), as well as in Uganda (98%) and Suriname (100%). All isolates from Suriname contained the chloroquine-resistant SVMNT haplotype typical of South American isolates, and 98% of isolates from Uganda possessed the chloroquine-resistant CVIET haplotype characteristic of Southeast Asian/African strains. However, of 246 P. falciparum isolates from across India that contained the molecular marker for chloroquine resistance, 81% contained the SVMNT haplotype. In conclusion, the prevalence of CRPF malaria was high in geographically dispersed regions of India, and the primary haplotype observed, SVMNT, did not support a presumed geographic spread from contiguous Southeast Asia.