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Dive into the research topics where Helen Varker is active.

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Featured researches published by Helen Varker.


American Journal of Cardiology | 2009

Increasing Prevalence of Atrial Fibrillation and Flutter in the United States

Gerald V. Naccarelli; Helen Varker; Jay Lin; Kathy L. Schulman

The prevalence data for atrial fibrillation (AF) are dated. The present retrospective study estimated the current and projected prevalence of AF and atrial flutter (AFL) in the United States using a large national database. Claims data drawn from July 2004 to December 2005 from the MarketScan research databases from Thomson Reuters were used to identify patients aged >or=20 years with nontransient AF and/or AFL and age- and gender-matched controls without these conditions. Of the 21,648,681 patients in the databases, 242,903 (1.12%) had nontransient AF and/or AFL (222,605 AF only, 5,376 AFL only, and 14,922 AF and AFL). Patients with AF only, AFL only, and AF and AFL had a greater (p <0.001) prevalence of co-morbidities, including hypertension (62.0%, 61.3%, and 57.0%, respectively) and coronary artery disease (43.0%, 44.7%, and 44.5%, respectively), than matched controls (45.1% hypertension and 19.4% coronary artery disease). Applying the US Census Bureau population estimates to the prevalence rates for AF and/or AFL in the databases, it was estimated that 3.03 million persons in the United States had AF only, 0.07 million had AFL only, and 0.19 million had AF and AFL in 2005. The projected prevalence for 2050 was 7.56 million for AF only, 0.15 million for AFL only, and 0.44 million for AF and AFL. In conclusion, the current prevalence of AF and AFL is high and is projected to increase considerably by 2050. The current and projected increases in the prevalence of AF are greater than predicted by a previous sentinel study and might reflect more than the aging of the population.


Journal of Hospital Medicine | 2012

Duration of venous thromboembolism risk across a continuum in medically ill hospitalized patients.

Alpesh Amin; Helen Varker; Nicole Princic; Jay Lin; Stephen Thompson; Stephen S. Johnston

BACKGROUND Patients hospitalized for medical illness are at increased risk of venous thromboembolism (VTE), but the duration of risk is not well understood. OBJECTIVE To assess incidence and time course of symptomatic VTE following hospitalization for medical illness in a large, real-world patient population. DESIGN Data were extracted from the Thomson Reuters MarketScan(®) Inpatient Drug Link File. PATIENTS Those hospitalized with cancer, heart failure, severe lung disease, or infectious disease from 2005 to 2008. MEASUREMENTS The cumulative VTE risk over 180 days after admission was calculated using Kaplan-Meier analysis. VTE hazard was calculated on a daily basis and smoothed through LOESS regression. RESULTS The analysis included 11,139 medically ill patients, 46.7% and 8.8% of whom received pharmacological thromboprophylaxis during hospitalization and after discharge, respectively. The mean duration of prophylaxis during hospitalization was 5.0 days. Of the 11,139 patients, 366 (3.3%) experienced a symptomatic VTE event. VTE events were most frequent during days 0-9 (97 events), followed by days 10-19 (82 events). The mean length of hospital stay was 5.3 days, and 56.6% of all VTE events occurred after discharge. VTE hazard peaked at day 8, with 1.05 events per 1000 person-days. CONCLUSIONS The time course of VTE in medical patients shows that risk of symptomatic VTE is highest during the first 19 days after hospital admission, and extends into the period after discharge. Future research is warranted to investigate risks and benefits of reducing the incidence of VTE after discharge, including the role of improving thromboprophylaxis practices in the inpatient setting and extending thromboprophylaxis after hospitalization.


Bone | 2011

Cost burden of second fracture in the US health system.

Xue Song; Nianwen Shi; Enkhe Badamgarav; Joel Kallich; Helen Varker; Gregory Lenhart; Jeffery R. Curtis

OBJECTIVES This retrospective claim-based study assessed 1-year medical costs associated with second fracture(s) for patients over 50 years old with an initial closed hip, clinical vertebral or non-hip non-vertebral (NHNV) fracture using 2002-2008 MarketScan® Commercial and Medicare Supplemental Databases. METHODS Patients with incident fracture and ≥12-month pre-period and follow-up period from the incident fracture were extracted. Index date was the first subsequent fracture date for patients with subsequent fracture during the 12-month (cases); index dates for patients without subsequent fractures during the 12-month follow-up (controls) were randomly assigned based on the distribution of index dates of cases. Total costs were examined during the 12-month follow-up period using generalized linear models. A decomposition analysis of the incremental costs attributable to the second fracture was conducted to examine what proportion of the difference was due to different patient characteristics and what proportion was due to different model structures between cases and controls. RESULTS For privately insured patients with hip, vertebral, or NHNV fracture, the 1-year second fracture rate was 8.0%, 5.1%, and 4.0%, and 1-year incremental costs were


American Journal of Cardiovascular Drugs | 2012

Patterns and Predictors of Use of Warfarin and Other Common Long-Term Medications in Patients with Atrial Fibrillation

Xue Song; Stephen Sander; Helen Varker; Alpesh Amin

47,351,


American Journal of Health-system Pharmacy | 2012

Impact of atrial fibrillation and oral anticoagulation on hospital costs and length of stay

Xue Song; Stephen Sander; Barbara H. Johnson; Helen Varker; Alpesh Amin

43,238, and


BMC Nephrology | 2014

Red blood cell (RBC) transfusion rates among US chronic dialysis patients during changes to Medicare end-stage renal disease (ESRD) reimbursement systems and erythropoiesis stimulating agent (ESA) labels

Katherine Cappell; Sanatan Shreay; Zhun Cao; Helen Varker; Carly J. Paoli; Matthew Gitlin

23,852, respectively; for Medicare patients, the corresponding rates and costs were 8.8%, 9.2%, and 8.2%, and


Lung Cancer | 2011

Treatment of lung cancer patients and concomitant use of drugs interacting with cytochrome P450 isoenzymes

Xue Song; Helen Varker; Michel Eichelbaum; Peter Stopfer; Mehdi Shahidi; Kathleen Wilson; Rolf Kaiser; Henrik W. Finnern

18,645,


BMC Nephrology | 2012

Outpatient red blood cell transfusion payments among patients on chronic dialysis.

Matthew Gitlin; J Andrew Lee; David Spiegel; Jeffrey L. Carson; Xue Song; Brian Custer; Zhun Cao; Katherine Cappell; Helen Varker; Shaowei Wan; Akhtar Ashfaq

19,702, and


Clinical Therapeutics | 2016

Prescribing Patterns of Oral Antineoplastic Therapies Observed in the Treatment of Patients With Advanced Prostate Cancer Between 2012 and 2014: Results of an Oncology EMR Analysis

Elisabetta Malangone-Monaco; K. Foley; Helen Varker; Kathleen Wilson; Scott McKenzie; Lorie Ellis

19,697. Nationally projected annual cost of second fracture was


Clinical Colorectal Cancer | 2017

Real-world Direct Health Care Costs for Metastatic Colorectal Cancer Patients Treated With Cetuximab or Bevacizumab-containing Regimens in First-line or First-line Through Second-line Therapy

Stephen S. Johnston; Kathleen Wilson; Helen Varker; Elisabetta Malangone-Monaco; Paul Juneau; Ellen Riehle; Sacha Satram-Hoang; Nicolas Sommer; Sarika Ogale

834 (95% confidence interval:

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Alice Huang

Truven Health Analytics

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Alpesh Amin

University of California

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Ellen Riehle

Truven Health Analytics

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