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Statistics and Probability

2010

Survival Analysis

Articles 1 - 8 of 8

Full-Text Articles in Life Sciences

Communitywide Trends In The Use And Outcomes Associated With Beta-Blockers In Patients With Acute Myocardial Infarction: The Worcester Heart Attack Study, Helme Silvet, Frederick Spencer, Jorge Yarzebski, Darleen Lessard, Joel Gore, Robert Goldberg Jul 2010

Communitywide Trends In The Use And Outcomes Associated With Beta-Blockers In Patients With Acute Myocardial Infarction: The Worcester Heart Attack Study, Helme Silvet, Frederick Spencer, Jorge Yarzebski, Darleen Lessard, Joel Gore, Robert Goldberg

Jorge L. Yarzebski

BACKGROUND: Despite the benefits associated with beta-blocker therapy in patients with acute myocardial infarction (AMI), limited recent data are available describing the extent of use of this therapy and the associated hospital and long-term outcomes, particularly from the perspective of a population-based study. Data are also limited about the characteristics of patients with AMI who do not receive beta-blockers. This study examines more than 2 decades of trends in the use of beta-blockers in hospitalized patients with AMI. METHODS: Communitywide study of 10,374 patients hospitalized with confirmed AMI in all metropolitan Worcester hospitals during 12 annual periods between 1975 ...


Two-Decade-Long Trends (1975-1997) In The Incidence, Hospitalization, And Long-Term Death Rates Associated With Complete Heart Block Complicating Acute Myocardial Infarction: A Community-Wide Perspective, Frederick Spencer, Samer Jabbour, Darleen Lessard, Jorge Yarzebski, Shmuel Ravid, Virginia Zaleskas, Michael Hyder, Joel Gore, Robert Goldberg Jul 2010

Two-Decade-Long Trends (1975-1997) In The Incidence, Hospitalization, And Long-Term Death Rates Associated With Complete Heart Block Complicating Acute Myocardial Infarction: A Community-Wide Perspective, Frederick Spencer, Samer Jabbour, Darleen Lessard, Jorge Yarzebski, Shmuel Ravid, Virginia Zaleskas, Michael Hyder, Joel Gore, Robert Goldberg

Jorge L. Yarzebski

BACKGROUND: The purpose of this community-wide study was to describe a >2-decade-long experience (1975-97) in the incidence and death rates associated with complete heart block (CHB) in patients with acute myocardial infarction (AMI). Limited population-based data exist describing recent, and changes with time therein, incidence and case-fatality rates associated with CHB complicating AMI.

METHODS: We conducted an observational study of 9082 metropolitan Worcester, Mass, residents (1990 census = 437,000) hospitalized with validated AMI in all greater Worcester hospitals during 11 1-year periods between 1975 and 1997.

RESULTS: Overall, CHB developed in 5.0% of patients with AMI. The incidence rates ...


Trends In Atrial Fibrillation Complicating Acute Myocardial Infarction, Jane Saczynski, David Mcmanus, Zheng Zhou, Frederick Spencer, Jorge Yarzebski, Darleen Lessard, Joel Gore, Robert Goldberg Jul 2010

Trends In Atrial Fibrillation Complicating Acute Myocardial Infarction, Jane Saczynski, David Mcmanus, Zheng Zhou, Frederick Spencer, Jorge Yarzebski, Darleen Lessard, Joel Gore, Robert Goldberg

Jorge L. Yarzebski

Atrial fibrillation (AF) is a common complication of acute myocardial infarction (AMI) and this arrhythmia is associated with increased morbidity and mortality in patients with AMI. Limited information is available, however, about changing, and contemporary, trends in the incidence and death rates associated with AF complicating AMI. We examined the magnitude and impact of AF and the risk of stroke and hospital and long-term death rates in a population-based study of patients hospitalized with AMI. The study population consisted of 7,513 residents of the Worcester, Massachusetts, metropolitan area hospitalized with AMI at all greater Worcester medical centers during 9 ...


Twenty-Two Year (1975 To 1997) Trends In The Incidence, In-Hospital And Long-Term Case Fatality Rates From Initial Q-Wave And Non-Q-Wave Myocardial Infarction: A Multi-Hospital, Community-Wide Perspective, Mark Furman, Harold Dauerman, Robert Goldberg, Jorge Yarzebski, Darleen Lessard, Joel Gore Jul 2010

Twenty-Two Year (1975 To 1997) Trends In The Incidence, In-Hospital And Long-Term Case Fatality Rates From Initial Q-Wave And Non-Q-Wave Myocardial Infarction: A Multi-Hospital, Community-Wide Perspective, Mark Furman, Harold Dauerman, Robert Goldberg, Jorge Yarzebski, Darleen Lessard, Joel Gore

Jorge L. Yarzebski

OBJECTIVES: The goal of this study was to examine long-term trends in the incidence, in-hospital and long-term mortality patterns in patients with an initial non-Q-wave myocardial infarction (NQWMI) as compared with those with an initial Q-wave myocardial infarction (QWMI). BACKGROUND: Limited data are available describing trends in the incidence and mortality from an initial QWMI and NQWMI from a multi-hospital community-wide perspective. METHODS: Our study was an observational study of 5,832 metropolitan Worcester, Massachusetts residents (1990 census = 437,000) hospitalized with validated initial acute MI in all greater Worcester hospitals during 11 annual periods between 1975 and 1997. RESULTS ...


Recent And Temporal Trends (1975 To 1999) In The Treatment, Hospital, And Long-Term Outcomes Of Hispanic And Non-Hispanic White Patients Hospitalized With Acute Myocardial Infarction: A Population-Based Perspective, Jorge Yarzebski, Carmen Bujor, Darleen Lessard, Joel Gore, Robert Goldberg Jul 2010

Recent And Temporal Trends (1975 To 1999) In The Treatment, Hospital, And Long-Term Outcomes Of Hispanic And Non-Hispanic White Patients Hospitalized With Acute Myocardial Infarction: A Population-Based Perspective, Jorge Yarzebski, Carmen Bujor, Darleen Lessard, Joel Gore, Robert Goldberg

Jorge L. Yarzebski

BACKGROUND: Extremely limited population-based data are available describing recent and temporal trends in the characteristics, treatment, and outcomes of Hispanic and non-Hispanic white patients hospitalized with acute myocardial infarction (AMI).

METHODS: This was a community-based, observational study of 9649 greater Worcester residents hospitalized in all hospitals serving the Worcester, Massachusetts, metropolitan area in 12 one-year periods between 1975 and 1999. In the total study sample, 171 (2%) patients were Hispanic. Hispanic patients were matched with 395 non-Hispanic white patients on the basis of age, sex, and year of hospitalization.

RESULTS: Hispanics were more likely to present to greater Worcester hospitals ...


Meta-Analysis For Surrogacy: Accelerated Failure Time Models And Semicompeting Risks Modelling, Debashis Ghosh, Jeremy M. Taylor, Daniel J. Sargent Jan 2010

Meta-Analysis For Surrogacy: Accelerated Failure Time Models And Semicompeting Risks Modelling, Debashis Ghosh, Jeremy M. Taylor, Daniel J. Sargent

Debashis Ghosh

There has been great recent interest in the medical and statistical literature in the assessment and validation of surrogate endpoints as proxies for clinical endpoints in medical studies. More recently, authors have focused on using meta-analytical methods for quanti cation of surrogacy. In this article, we extend existing procedures for analysis based on the accelerated failure time model to this setting. An advantage of this approach relative to proportional hazards model is that it allows for analysis in the semi-competing risks setting, where we constrain the surrogate endpoint to occur before the true endpoint. A novel principal components procedure is ...


Combining Multiple Models With Survival Data: The Phase Algorithm, Debashis Ghosh, Zheng Yuan Jan 2010

Combining Multiple Models With Survival Data: The Phase Algorithm, Debashis Ghosh, Zheng Yuan

Debashis Ghosh

In many scientic studies, one common goal is to develop good prediction rules based on a set of available measurements. This paper proposes a model averaging methodology using proportional hazards regression models to construct new estimators of predicted survival probabilities. A screening step based on an adaptive searching algorithm is used to handle large numbers of covariates. The nite-sample properties of the proposed methodology is assessed using simulation studies. Application of the method to a cancer biomarker study is also given.


Semiparametric Analysis Of Recurrent Events: Artificial Censoring, Truncation, Pairwise Estimation And Inference, Debashis Ghosh Dec 2009

Semiparametric Analysis Of Recurrent Events: Artificial Censoring, Truncation, Pairwise Estimation And Inference, Debashis Ghosh

Debashis Ghosh

The analysis of recurrent failure time data from longitudinal studies can be complicated by the presence of dependent censoring. There has been a substantive literature that has developed based on an artificial censoring device. We explore in this article the connection between this class of methods with truncated data structures. In addition, a new procedure is developed for estimation and inference in a joint model for recurrent events and dependent censoring. Estimation proceeds using a mixed U-statistic based estimating function approach. New resampling-based methods for variance estimation and model checking are also described. The methods are illustrated by application to ...