Limin X Clegg

U.S. Department of Veterans Affairs | VA

Objectives: In this population-based cohort study, we assessed baseline risk factors for homelessness, including the role of service in the Iraq or Afghanistan conflicts, among a large cohort of recent veterans. Methods: Data for this study came from administrative records for 310,685 veterans who separated from active military duty from July 1,...

Trends in incidence or mortality rates over a specified time interval are usually described by the conventional annual per cent change (cAPC), under the assumption of a constant rate of change. When this assumption does not hold over the entire time interval, the trend may be characterized using the annual per cent changes from segmented analysis (...

The National Longitudinal Mortality Study (NLMS) offers the advantage of assessing mortality in a representative population of the United States. To evaluate health disparities associated with lung cancer and chronic obstructive pulmonary disease (COPD) mortality in the United States and whether these associations are similar between these outcomes...

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...

Testicular cancer is the most common cancer in men age 25 to 35 years. We examined therapy, compliance with guidelines, and survival in a population based sample of men newly diagnosed with testicular cancer. We analyzed the National Cancer Institute's (NCI) patterns of care data on 702 men diagnosed with testicular cancer in 1999. These studies su...

Epidemiologic research into cancer and subsequent decision making to reduce the cancer burden in the population are dependent on the quality of available data. The more reliable the data, the more confident we can be that the decisions made would have the desired effect in the population. The North American Association of Central Cancer Registries...

This report summarizes the results of the Department of Defense (DoD) and Veterans Affairs (VA) Inspectors General (IG) interagency evaluation of the health care transition processes for Service members severely injured in Operations Iraqi Freedom and Enduring Freedom (OIF/OEF). On March 10, 2005, the Under Secretary of Defense for Personnel and Re...

To examine the extent of use of specific therapies in clinical practice, and their relationship to therapies validated in clinical trials. The US National Cancer Institutes' Patterns of Care study was used to examine therapies and survival of patients diagnosed in 2001 with histologically-confirmed gastroesophageal adenocarcinoma (n = 1356). The st...

The prognosis for women who have breast cancer detected by mammography is more favorable than that for women who have breast cancer detected by other methods, even after controlling for tumor characteristics. In the current study, the authors explored whether detection by mammography was associated with greater use of guideline-consistent breast ca...

To determine whether women diagnosed with cervical cancer within the U.S. Department of Defense (DOD) Military Health Care System received treatment within standard guidelines and whether survival was influenced by implementation of these guidelines. We identified 621 women treated from 1994 to 2002. Guideline therapy was defined as hysterectomy or...

We investigated the increased incidence of early-stage breast cancer with micrometastatic lymph node involvement. Breast cancer incidence trends from 1990 through 2002 in the US Surveillance, Epidemiology, and End Results Program catchment area were analyzed. Joinpoint regression was used to show the annual percentage change (APC) in breast cancer...

Population-based cancer registry data from the Surveillance, Epidemiology, and End Results (SEER) Program at the National Cancer Institute are based on medical records and administrative information. Although SEER data have been used extensively in health disparities research, the quality of information concerning race, Hispanic ethnicity, and immi...

The age-adjusted cancer rates are defined as the weighted average of the age-specific cancer rates, where the weights are positive, known, and normalized so that their sum is 1. Fay and Feuer developed a confidence interval for a single age-adjusted rate based on the gamma approximation. Fay used the gamma approximations to construct an F interval...

Over the past decade, clinical trials have proved the efficacy of treatments for colorectal cancer (CRC). This study tracks dissemination of these treatments for patients diagnosed with stage II and III disease and compares risk of death for those who received guideline therapy to those who did not. We conducted a stratified randomly sampled, popul...

Cancer prevalence is the proportion of people in a population diagnosed with cancer in the past and still alive. One way to estimate prevalence is via population-based registries, where data on diagnosis and life status of all incidence cases occurring in the covered population are collected. In this paper, a method to estimate the complete prevale...

We describe trends in the use of chemotherapy and hormonal therapy by nodal and estrogen receptor (ER) status in women with early-stage breast cancer. Cases were randomly sampled from the population-based Surveillance, Epidemiology and End Results (SEER) program and physician verified treatment was examined. A total of 9,481 women, aged 20 years an...

This study estimates the impact of type of insurance coverage on the receipt of guideline therapy in a population-based sample of cancer patients treated in the community. Patients (n = 7,134) from the National Cancer Institute's Patterns of Care studies who were newly diagnosed with 11 different types of cancer were analyzed. The definition of gui...

Population-based cancer registries, such as those included in the Surveillance, Epidemiology, and End-Results (SEER) Program, offer tremendous research potential beyond traditional surveillance activities. We describe the expansion of SEER registries to gather formalin-fixed, paraffin-embedded tissue from cancer patients on a population basis. Popu...

New therapies have enhanced treatment of non-Hodgkin's lymphoma (NHL), but extent of treatment use in community practice is unknown. We conducted a population-based study of NHL patients diagnosed in 1999 with histologically confirmed NHL (n = 947) residing in areas covered by the Surveillance, Epidemiology, and End Results program. We performed an...

The ability to use archival tissue to test externally valid hypotheses of carcinogenesis is dependent on the availability of population-based samples of cancer tissue. Tissue microarrays (TMAs) provide an efficient format for developing population-based samples of tissue. A TMA was constructed consisting of archival tissue from patients diagnosed w...

Non-Hispanic black women are less often diagnosed with endometrial cancer than are non-Hispanic white women, but are more likely to die of their disease. Reasons for this disparity in outcome are not well understood. The Surveillance, Epidemiology, and End-Results Program data were used to sample women newly diagnosed in 1998 with cancer of the cor...

To evaluate treatment patterns, including lack of treatment, among women diagnosed with cervical cancer in the United States. Using the National Cancer Institute's (NCI's) Surveillance, Epidemiology, and End Results (SEER) program, we identified 13,715 women diagnosed with invasive cervical cancer between 1992 and 1999 and eligible for inclusion in...

The Surveillance, Epidemiology, and End Results (SEER) program of the National Cancer Institute is an authoritative source of cancer incidence statistics in the United States. The SEER program is a consortium of population-based cancer registries from different areas of the country. Each registry is charged with collecting data on all cancers that...

The advent of therapeutic monoclonal antibodies has enhanced the efficacy of NHL treatment. In recent years, these immuno-therapies have been increasingly used in therapy. We conducted a population-based study of NHL treatment practices in the US using a stratified random sample of patients diagnosed in 1999 with histologically confirmed NHL (n=939...

Over the past decade new drugs have significantly altered the treatment paradigm for patients with Chronic Lymphocytic Leukemia (CLL). Fludarabine, rituximab and alemtuzumab have established efficacy in CLL, but the patterns of disease presentation and course, and clinical intervention in general practice has not been captured. The Division of Canc...

The American Cancer Society (ACS), the Centers for Disease Control and Prevention (CDC), the National Cancer Institute (NCI), and the North American Association of Central Cancer Registries (NAACCR) collaborate annually to provide updated information regarding cancer occurrence and trends in the U.S. This year's report features a special section on...

Merkel cell carcinoma (MCC) is a rare, aggressive skin cancer. We sought to describe primary MCC incidence trends, epidemiology, and predictors of survival. The population covered by the Surveillance, Epidemiology, and End Results Program was analyzed as a prospective cohort. We measured age-adjusted incidence rates (per 100,000 person-years) and e...

We examined patterns of care in a population-based sample of 601 ovarian cancer patients diagnosed in 1991, and a sample of 566 women was selected in 1996 to examine trends in care. Patient cases were sampled from within the Surveillance, Epidemiology, and End Results program. Medical records were reabstracted, and treatment data were verified with...

The recent article by Clegg et al¹ presents valuable information regarding survival following cancers of the prostate, breast, lung, and colon/rectum among the major racial/ethnic groups in the United States based on data from the Surveillance, Epidemiology, and End Results (SEER) program. Such population-based survival statistics can provide a bas...

The aim was to describe the epidemiology of endocrine tumors of the cervix in comparison with invasive squamous cell carcinomas using population-based data reported to the Surveillance, Epidemiology and End-Results (SEER) program. Retrospective analysis of actively followed cases reported to SEER from 1973 to 1998. Incidence, demographic characteri...

Acute lymphoblastic leukemia (ALL) represents the most common malignancy of childhood. Its incidence peaks in children just before school entry age; i.e., in 2-3 year olds. It is known to be more common in white children in the USA; the incidence is also higher in boys than girls. We reviewed the 5,379 cases of ALL among persons under 20 years of a...

Cancer incidence rates and trends are a measure of the cancer burden in the general population. We studied the impact of reporting delay and reporting error on incidence rates and trends for cancers of the female breast, colorectal, lung/bronchus, prostate, and melanoma. Based on statistical models, we obtained reporting-adjusted (i.e., adjusted fo...

We propose a new Poisson method to estimate the variance for prevalence estimates obtained by the counting method described by Gail et al. (1999, Biometrics 55, 1137-1144) and to construct a confidence interval for the prevalence. We evaluate both the Poisson procedure and the procedure based on the bootstrap proposed by Gail et al. in simulated sa...

It has been suggested that cerebellar medulloblastoma (M) and primitive neuroectodermal tumors (PNET) arising elsewhere in the nervous system, represent a single entity (M/PNET), although this concept is controversial. Cancer registries permit population-based description of cases reported as medulloblastoma, those reported as PNET and description...

Background Available cancer statistics pertain primarily to white and African American populations. This study describes racial or ethnic patterns of cancer-specific survival and relative risks (RRs) of cancer death for all cancers combined and for cancers of the colon and rectum, lung and bronchus, prostate, and female breast for the 6 major US r...

Available cancer statistics pertain primarily to white and African American populations. This study describes racial or ethnic patterns of cancer-specific survival and relative risks (RRs) of cancer death for all cancers combined and for cancers of the colon and rectum, lung and bronchus, prostate, and female breast for the 6 major US racial or eth...

Cancer of the appendix is an uncommon disease that is rarely suspected rarely before surgery. Although several case series of these tumors have been published, little research has been anchored in population-based data on cancer of the appendix. This analysis included all actively followed cases of appendiceal neoplasms reported to the National Can...

Cancer survival information is available only in areas covered by cancer registration. The objective of this study is to project cancer survival for the entire US as well as states from survival data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program. Five-year breast, prostate, and colorectal cancer rel...

Many men diagnosed with clinically localized prostate cancer are initially treated conservatively, receiving neither surgery nor radiotherapy for the first year. Treatment patterns and quality-of-life outcomes have not been previously reported for a population-based sample of such men. A population-based random sample of men (n = 661) from six geog...

Medical records are generally accepted as the most accurate source of information documenting cancer treatments. However, as the health care system becomes more decentralized and more cancer care is delivered in outpatient settings, it is increasingly difficult and expensive to review records from the many surgeons and medical/radiation oncolog...

To compare health-related quality-of-life outcomes after primary androgen deprivation (AD) therapy with orchiectomy versus luteinizing hormone-releasing hormone (LHRH) agonists for patients with prostate cancer. Men (n = 431) newly diagnosed with all stages of prostate cancer from six geographic regions who participated in the Prostate Cancer Outco...

Few studies have determined whether carotid artery intima-media thickness (IMT) is associated prospectively with risk of first ischemic stroke. In the Atherosclerosis Risk in Communities Study, carotid IMT, an index of generalized atherosclerosis, was defined as the mean of IMT measured by B-mode ultrasonography at six sites of the carotid arteries...

Objective: Surveillance of chronic diseases includes monitoring trends in age-adjusted rates in the general population. Statistics that are calculated to describe and compare trends include the annual percent change and the percent change for a specified time period. However, it is also of interest to determine the contribution specific diseases ma...

. Hazard functions for correlated censored data are usually formulated through the Cox regression model in a marginal regression framework. We investigate properties of the maximum pseudo partial likelihood estimator vector under a possibly misspecified marginal Cox regression model. The estimator vector is shown to be consistent for an implicitly...

To develop protocols to photograph and evaluate retinal vascular abnormalities in the Atherosclerosis Risk in Communities (ARIC) Study; to test reproducibility of the grading system; and to explore the relationship of these microvascular changes with blood pressure. Population-based, cross-sectional study. Among 4 examination centers, 11,114 partic...

To describe the prevalence of age-related maculopathy (ARM) in blacks and whites and its relation to macrovascular disease and risk factors thereof in a population studied for cardiovascular disease risk factors and outcomes. A biracial population of 11532 adults (ranging from 48-72 years of age; 8984 whites and 2548 blacks) living in 4 US communit...

In multivariate failure time data analysis, a marginal regression modeling approach is often preferred to avoid assumptions on the dependence structure among correlated failure times. In this paper, a marginal mixed baseline hazards model is introduced. Estimating equations are proposed for the estimation of the marginal hazard ratio parameters. Th...

The prostate-specific antigen test was approved by the U.S. Food and Drug Administration in 1986 to monitor the disease status in patients with prostate cancer and, in 1994, to aid in prostate cancer detection. However, after 1986, the test was performed on many men who had not been previously diagnosed with prostate cancer, apparently resulting in...

To clarify the determinants of contemporary trends in mortality from coronary heart disease (CHD), we conducted surveillance of hospital admissions for myocardial infarction and of in-hospital and out-of-hospital deaths due to CHD among 35-to-74-year-old residents of four communities of varying size in the United States (a total of 352,481 persons...

Few studies have determined whether greater carotid artery intima-media thickness (IMT) in asymptomatic individuals is associated prospectively with increased risk of coronary heart disease (CHD). In the Atherosclerosis Risk in Communities Study, carotid IMT, an index of generalized atherosclerosis, was defined as the mean of IMT measurements at si...

Few studies of physical activity and coronary heart disease (CHD) have included women or blacks. We examined this association in a biracial cohort of 45- to 64-yr-old adults. We related the sports, leisure, and work indices developed by J. A. H. Baecke et al. to CHD incident events (N = 97 in women, N = 223 in men) over 4-7 yr in the Atherosclerosi...

This study compared rates of performance of cardiac procedures in relation to gender, race, and geographic location in patients hospitalized for myocardial infarction. The Atherosclerosis Risk in Communities (ARIC) study provides population data and standardized data collection methods. Hospital records of eligible people aged 35 to 74 years were a...