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Biostatistics Commons

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Full-Text Articles in Biostatistics

Addressing Bias In Non-Experimental Studies Assessing Treatment Outcomes In Prostate Cancer, David E. Guy Jun 2021

Addressing Bias In Non-Experimental Studies Assessing Treatment Outcomes In Prostate Cancer, David E. Guy

Electronic Thesis and Dissertation Repository

We evaluated the ability of matching techniques to balance baseline characteristics between treatment groups using non-experimental data. We identified a set of balance diagnostics that assessed key differences in baseline covariates with potential for confounding. These diagnostics were used in a novel systematic approach to developing and evaluating models for use in propensity score matching that optimized balance and data retention. We then compared the performance of propensity score and coarsened exact matching strategies in optimizing balance and data retention, using non-experimental data from a pan-Canadian prostate cancer database. Both matching techniques balanced baseline covariates adequately and retained approximately 70% …


Physical Activity Across The Lifespan And Liver Cancer Incidence In The Nih-Aarp Diet And Health Study Cohort., Hannah Arem, Erikka Loftfield, Pedro F Saint-Maurice, Neal D Freedman, Charles E Matthews Apr 2018

Physical Activity Across The Lifespan And Liver Cancer Incidence In The Nih-Aarp Diet And Health Study Cohort., Hannah Arem, Erikka Loftfield, Pedro F Saint-Maurice, Neal D Freedman, Charles E Matthews

Epidemiology Faculty Publications

While liver cancer rates in the United States are increasing, 5-year survival is only 17.6%, underscoring the importance of prevention. Physical activity has been associated with lower risk of developing liver cancer, but most studies assess physical activity only at a single point in time, often in midlife. We utilized physical activity data from 296,661 men and women in the NIH-AARP Diet and Health Study cohort to test whether physical activity patterns over the life course could elucidate the importance of timing of physical activity on liver cancer risk. We used group modeling of longitudinal data to create physical activity …


Pre- And Post-Diagnosis Physical Activity, Television Viewing, And Mortality Among Hematologic Cancer Survivors., Daniela Schmid, Gundula Behrens, Hannah Arem, Christina Hart, Wolfgang Herr, Carmen Jochem, Charles E Matthews, Michael F Leitzmann Jan 2018

Pre- And Post-Diagnosis Physical Activity, Television Viewing, And Mortality Among Hematologic Cancer Survivors., Daniela Schmid, Gundula Behrens, Hannah Arem, Christina Hart, Wolfgang Herr, Carmen Jochem, Charles E Matthews, Michael F Leitzmann

Epidemiology Faculty Publications

PURPOSE: The associations of physical activity and television (TV) viewing with mortality risk among individuals with hematologic malignancies remain unclear.

METHODS: We examined the relations of physical activity and TV viewing time before and after diagnosis with mortality among 5182 U.S. adults aged 50-71 years from the NIH-AARP Diet and Health Study cohort who survived a first primary hematologic cancer between 1995-1996 and 2011.

RESULTS: For the pre- and post-diagnosis analyses, we confirmed 2606 and 613 deaths respectively. In multivariable-adjusted Cox proportional hazard regression models, comparing high (≥4 hrs/wk) versus low (/wk) activity levels, pre-diagnosis physical activity was associated with …


Cancer-Specific Mortality, Cure Fraction, And Noncancer Causes Of Death Among Diffuse Large B-Cell Lymphoma Patients In The Immunochemotherapy Era., Nadia Howlader, Angela B Mariotto, Caroline Besson, Gita Suneja, Kim Robien, Naji Younes, Eric A Engels May 2017

Cancer-Specific Mortality, Cure Fraction, And Noncancer Causes Of Death Among Diffuse Large B-Cell Lymphoma Patients In The Immunochemotherapy Era., Nadia Howlader, Angela B Mariotto, Caroline Besson, Gita Suneja, Kim Robien, Naji Younes, Eric A Engels

Epidemiology Faculty Publications

BACKGROUND

Survival after the diagnosis of diffuse large B-cell lymphoma (DLBCL) has been increasing since 2002 because of improved therapies; however, long-term outcomes for these patients in the modern treatment era are still unknown.

METHODS

Using Surveillance, Epidemiology, and End Results data, this study first assessed factors associated with DLBCL-specific mortality during 2002-2012. An epidemiologic risk profile, based on clinical and demographic characteristics, was used to stratify DLBCL cases into low-, medium-, and high-risk groups. The proportions of DLBCL cases that might be considered cured in these 3 risk groups was estimated. Risks of death due to various noncancer causes …


New Malignancies After Squamous Cell Carcinoma And Melanomas: A Population-Based Study From Norway, Trude E. Robsahm, Margaret R. Karagas, Judy R. Rees, Astri Syse Mar 2014

New Malignancies After Squamous Cell Carcinoma And Melanomas: A Population-Based Study From Norway, Trude E. Robsahm, Margaret R. Karagas, Judy R. Rees, Astri Syse

Dartmouth Scholarship

Skin cancer survivors experience an increased risk for subsequent malignancies but the associated risk factors are poorly understood. This study examined the risk of a new primary cancer following an initial skin cancer and assessed risk factors associated with second primary cancers.


The Spatial Distribution Of Cancer Incidence In Fars Province: A Gis-Based Analysis Of Cancer Registry Data, Ali Goli, Mahbobeh Oroei, Mehdi Jalalpour, Hossein Faramarzi, Mehrdad Askarian Oct 2013

The Spatial Distribution Of Cancer Incidence In Fars Province: A Gis-Based Analysis Of Cancer Registry Data, Ali Goli, Mahbobeh Oroei, Mehdi Jalalpour, Hossein Faramarzi, Mehrdad Askarian

Civil and Environmental Engineering Faculty Publications

Background: Cancer is a major health problem in the developing countries. Variations of its incidence rate among geographical areas are due to various contributing factors. This study was performed to assess the spatial patterns of cancer incidence in the Fars Province, based on cancer registry data and to determine geographical clusters.

Methods: In this cross sectional study, the new cases of cancer were recorded from 2001 to 2009. Crude incidence rate was estimated based on age groups and sex in the counties of the Fars Province. Age standardized incidence rates (ASR) per 100,000 was calculated in each year. …


Evaluation Of The Survival Effect For Various Treatment Modalities Among Stage Ii And Iii Rectal Cancer Patients In California, 1994-2009, Myung Mi Cho Dec 2012

Evaluation Of The Survival Effect For Various Treatment Modalities Among Stage Ii And Iii Rectal Cancer Patients In California, 1994-2009, Myung Mi Cho

Loma Linda University Electronic Theses, Dissertations & Projects

Background: European trials evaluating the effect of preoperative (PreOP) versus postoperative chemoradiotherapy (PostOP CRT) found no survival benefit. However, the effect of a change from PostOP to PreOP CRT has not been evaluated in a population-based setting. We sought to evaluate multimodal treatment changes and overall survival for perioperative (PeriOP) CRT versus surgery alone and for PreOP versus PostOP CRT from 1994 through 2009 among patients receiving radical surgery for stage II and III rectal cancer (RC).

Patients and Methods: We conducted a nonconcurrent cohort study evaluating demographic predictors of multimodal therapy for stage II and III RC using …


A Flow Cytometric Analysis Of Immunocyte Populations In Peripheral Blood And Pleural Effusions Of Patients With Cancer, Mandy L. Bohn Jun 1991

A Flow Cytometric Analysis Of Immunocyte Populations In Peripheral Blood And Pleural Effusions Of Patients With Cancer, Mandy L. Bohn

Loma Linda University Electronic Theses, Dissertations & Projects

Two-color flow cytometric analysis was performed on paired samples of peripheral blood (PB) and pleural effusions (PE) of patients with metastatic malignancies. The purpose of these analyses was to test the hypothesis that there are significant differences in the distribution of immunocyte populations in the PE compared to that of the PB.

The majority of the pleural fluid immunocytes were CD3+ cells. The ratio of CD4+ to CD8+ cells was higher in the PE compared to PB. Levels of CD8+, CD19+ and CD14+ cells were not significantly different in the PE compared to the levels in the PB. CD16+CD56+ cells …