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Biomedical subjects

R Ballard-Barbash

Publications and source records attributed to R Ballard-Barbash.

At least 19 recordsLinked to original sources
PubMed2006

Body mass index and all-cause mortality in a nationwide US cohort.

OBJECTIVE: To investigate whether the nature of the relationship between body mass index (BMI (kg/m2)) and all-cause mortality is direct, J- or U-shaped, and whether this relationship changes as people age. DESIGN: Prospective nationwide cohort study of US radiologic technologists (USRT). SUBJECTS: Sixty-four thousand seven hundred and thirty-three female and 19 011 male certified radiation technologists. METHODS: We prospectively followed participants from the USRT study who completed a mail survey in 1983-1989 through 2000. During an average of 14.7 years of follow-up or 1.23 million person-years, 2278 women and 1495 men died. Using Cox's proportional-hazards regression analyses, we analyzed the relationship between BMI and all-cause mortality by gender and by age group (<55 years; > or = 55 years). We also examined risk in never-smokers after the first 5 years of follow-up to limit bias owing to the confounding effects of smoking and illness-related weight loss on BMI and mortality. RESULTS: Risks were generally J-shaped for both genders and age groups. When we excluded smokers and the first 5 year of follow-up, risks were substantially reduced in those with low BMIs. In never-smoking women under the age of 55 years (excluding the initial 5-year follow-up period), risk rose as BMI increased above 21.0 kg/m2, whereas in older women, risk increased beginning at a higher BMI (> or = 25.0 kg/m2). Among younger men who never smoked (excluding the initial 5-year follow-up period), risk began to rise above a BMI of 23.0 kg/m2, whereas in older men, risk did not begin to increase until exceeding a BMI of 30.0 kg/m2. CONCLUSIONS: In younger/middle-aged, but not older, women and men, mortality risks appear directly related to BMI. The more complicated relationship between BMI and mortality in older subjects suggests the importance of assessing whether other markers of body composition better explain mortality risk in older adults.

Adult↗
PubMed2004

Association of body composition and weight history with breast cancer prognostic markers: divergent pattern for Hispanic and non-Hispanic White women.

Body composition and weight gain are breast cancer risk factors that may influence prognosis. The Health, Eating, Activity, and Lifestyle Study was designed to evaluate the relations of body composition, weight history, hormones, and lifestyle factors to prognosis for women with breast cancer. In the cross-sectional analysis of this cohort study specific to 150 Hispanic and 466 non-Hispanic White women in New Mexico diagnosed between 1996 and 1999, the authors hypothesized that obesity measures are associated with baseline prognostic markers and that these associations are modified by ethnicity. Ethnic-stratified multiple logistic regression analyses showed divergent results for a tumor size of 1.0 cm or more and, to a lesser extent, positive lymph node status. Among Hispanics, the highest quartile for body mass index (29.5 vs. <22.5 kg/m2: odds ratio (OR) = 0.16, 95% confidence interval (CI): 0.03, 0.84) and for waist circumference (> or =95.0 vs. <78.5 cm: OR = 0.09, 95% CI: 0.01, 0.78) was significantly associated with a reduced tumor size. In contrast, for overweight and obese non-Hispanic White women, there was an increased association with obesity-related measures, particularly striking for the highest quartile of waist circumference (OR = 2.76, 95% CI: 1.45, 5.26). These findings suggest that Hispanics may have a different breast cancer phenotype than non-Hispanic Whites, which associates differently with body composition and weight history.

Adult↗
PubMed2003

US physicians' attitudes toward genetic testing for cancer susceptibility.

Genetic testing for an inherited susceptibility to cancer is an emerging technology in medical practice. Little information is currently available about physicians' attitudes toward these tests. To assess US physicians' opinions on unresolved issues surrounding genetic testing, a 15-min survey was administered to a stratified random sample of 1,251 physicians from 8 specialties, selected from a file of all licensed physicians in the US (response rate = 71.0%). Dependent measures included physicians' attitudes toward genetic counseling and testing qualifications, availability of guidelines, patient confidentiality and insurance discrimination issues, and clinical utility of genetic tests. More than 89% of physicians reported a need for physician guidelines, 81% thought that patients with positive genetic test results are at risk for insurance discrimination, and more than 53% thought that it was difficult to ensure the confidentiality of test results. Almost 25% indicated that genetic tests for cancer susceptibility have too many inaccurate or ambiguous results; nearly 75% thought that clear guidelines are not available for managing patients with positive test results. Only 29% of physicians reported feeling qualified to provide genetic counseling to their patients. More than 84% of oncologists considered themselves qualified to recommend genetic testing to their patients compared with 40% of primary care physicians (PCPs), and 57% of tertiary care physicians (TCPs). US physicians expressed great uncertainty about issues surrounding genetic testing for cancer susceptibility. Results of this national survey underscore the need to provide physicians with clear guidelines on the use of genetic cancer susceptibility tests and effective medical training on their appropriate implementation.

Attitude of Health Personnel↗
PubMed2001

Progress in cancer screening over a decade: results of cancer screening from the 1987, 1992, and 1998 National Health Interview Surveys.

BACKGROUND: Screening to detect cancer early, an increasingly important cancer control activity, cannot be effective unless it is widely used. METHODS: Use of Pap smears, mammography, fecal occult blood tests (FOBTs), sigmoidoscopy, and digital rectal examination (DRE) was evaluated in the 1987, 1992, and 1998 National Health Interview Surveys. Levels and trends in screening use were examined by sex, age, and racial/ethnic group. The effects of income, educational level, and health care coverage were examined within age groups. Logistic regression analyses of 1998 data were used to develop a parsimonious, policy-relevant model. RESULTS: Use of all screening modalities increased over the period examined; for mammography and DRE, the increase was more rapid in the first half of the decade; for the Pap test and sigmoidoscopy, the increase was more rapid in the second half of the decade. Levels of colorectal cancer screening (both sigmoidoscopy and FOBTs) in 1998 were less than the level that prevailed a decade earlier for mammography. Patterns of change for all screening modalities differed between age, sex, and racial/ethnic groups, but prevalence of use during the study, within recommended time intervals, was consistently lower among groups with lower income and less education. Logistic regression analyses indicated that insurance coverage and, to a greater extent, usual source of care had strong independent associations with screening usage when age, sex, racial/ethnic group, and educational level were taken into account. CONCLUSIONS: While cancer screening is generally increasing in the United States, usage is relatively low for colorectal cancer screening and among groups that lack health insurance or a usual source of care.

Adult↗
PubMed2001

Evaluating the impact of population changes in diet, physical activity, and weight status on population risk for colon cancer (United States).

OBJECTIVE: To estimate the effects of observed population-level changes in risk factors on population risk and incidence of disease. METHODS: Trends in a set of risk factors for colon cancer (vegetable intake, red meat intake, alcohol consumption, physical activity levels, and weight status) were modeled for the US adult population over the years 1975-1995 and combined with relative risk estimates from epidemiologic studies and a probability distribution for the induction period to estimate the percentage change in incidence rates from 1985 to 1995 due to the five risk factors. A sensitivity analysis was performed to account for imprecision related to estimates of trends in behavior and epidemiologic risk. RESULTS: Increased vegetable intake and decreased intakes of red meat and alcohol reduced risk, while reduced physical activity and increased body mass index increased risk for colon cancer. When all five factors were considered together, change in the average population relative risk was small and the risk factors accounted for little of the recently observed decline in incidence. CONCLUSIONS: Although these factors have the potential to greatly affect risk of colon cancer and incidence rates, little of that potential was realized since adverse trends neutralized what progress had been made in the areas of vegetables, red meat, and alcohol consumption.

Adult↗
PubMed2001

Implementation of a 4-y, high-fiber, high-fruit-and-vegetable, low-fat dietary intervention: results of dietary changes in the Polyp Prevention Trial.

BACKGROUND: The Polyp Prevention Trial (PPT) was a multicenter randomized clinical trial designed to determine the effects of a high-fiber (4.30 g/MJ), high-fruit-and-vegetable (0.84 servings/MJ), low-fat (20% of energy from fat) diet on the recurrence of adenomatous polyps in the large bowel. OBJECTIVE: Our goal was to determine whether the PPT intervention plan could effect change in 3 dietary goals and to examine the intervention's effect on the intake of other food groups and nutrients. DESIGN: Participants with large-bowel adenomatous polyps diagnosed in the past 6 mo were randomly assigned to either the intervention (n = 1037) or the control (n = 1042) group and remained in the trial for 4 y. Three dietary assessment instruments were used to measure dietary change: food-frequency questionnaires (in 100% of the sample), 4-d food records (in a 20% random cohort), and 24-h dietary recalls (in a 10% random sample). RESULTS: Intervention participants made and sustained significant changes in all PPT goals as measured by the dietary assessment instruments; the control participants' intakes remained essentially the same throughout the trial. The absolute differences between the intervention and control groups over the 4-y period were 9.7% of energy from fat (95% CI: 9.0%, 10.3%), 1.65 g dietary fiber/MJ (95% CI: 1.53, 1.74), and 0.27 servings of fruit and vegetables/MJ (95% CI: 0.25, 0.29). Intervention participants also reported significant changes in the intake of other nutrients and food groups. The intervention group also had significantly higher serum carotenoid concentrations and lower body weights than did the control group. CONCLUSION: Motivated, free-living individuals, given appropriate support, can make and sustain major dietary changes over a 4-y period.

Adenomatous Polyps↗
PubMed2001

Aim for a healthy weight: what is the target?

The first guideline statement of the Year 2000 edition of Nutrition and Your Health: Dietary Guidelines for Americans is "Aim for a healthy weight." The purpose of this paper is to describe the evolution of the weight guideline and discuss some issues related to it. We reviewed current and previous editions of the Dietary Guidelines and the corresponding advisory committee reports. The weight guideline has evolved over the years into one that is complex and touches on a wide range of issues. The 2000 edition emphasizes weight loss more than previous editions. Unlike the other guidelines in the Dietary Guidelines, the weight guideline has a health outcome, a "healthy" weight, rather than a behavioral outcome as its goal. Also unlike the other guidelines, the weight guideline has become more medically oriented over time. The concept of healthy weight in the guidelines includes aspects of body composition, fat distribution and weight-related health conditions. It may be difficult for the public and even for health care providers to interpret some of the concepts included in the weight guideline. Issues related to the appropriate management of weight can be complex and may require a health care provider as a resource for interpretation. Rather than try to incorporate further clinical decision-making and weight loss guidance within the weight guideline, it may be more appropriate to refer the reader to a health care provider for guidance, as was done in previous editions.

Age Factors↗
PubMed2001

Be physically active each day. How can we know?

For the first time in its five versions, Nutrition and Your Health: Dietary Guidelines for Americans contains an apparently nondietary guideline recommending physical activity. Although new as a separate guideline, physical activity has been included in the weight guideline of previous versions. The current version recognizes the importance of physical activity to health beyond its effect on weight maintenance. The purpose of this paper is to examine what data are available or required to evaluate the level of physical activity in the population, particularly in light of current recommendations. The physical activity sections of several national surveys that assess individual behavior or activity-related policies are described. Surveillance of physical activity as a risk factor for chronic disease is critical because physical inactivity is highly prevalent, strongly associated with increased morbidity and mortality, costly and preventable. Determinants of physical activity behavior are also considered. These determinants are potentially important factors for surveillance and are critical components for planning successful interventions.

Adult↗
PubMed2001

Quality assurance for screening mammography: an international comparison.

STUDY OBJECTIVE: In 1998, the International Breast Cancer Screening Network (IBSN) sponsored an assessment of quality assurance policies and practices to define their scope for population-based screening mammography programmes across IBSN countries. DESIGN: Analysis of data from a survey designed to assess multiple elements of screening programme quality assurance, including organisation of quality assurance activities, mechanisms for site visits and accreditation, requirements for quality control and data systems, and inclusion of treatment, follow up, and programme evaluation in screening mammography quality assurance activities. PARTICIPANTS AND SETTING: IBSN representatives in 23 countries completed a comprehensive questionnaire between May and December 1998. MAIN RESULTS: Completed questionnaires were obtained from all 23 countries. Responses indicated that countries vary in their approaches to implementing quality assurance, although all monitor components of structure, process, and outcome. Nearly all have in place laws, surveillance mechanisms, or standards for quality assurance. In all countries, quality assurance activities extend beyond the screening mammography examination. CONCLUSIONS: The assessment has enhanced understanding of the organisation of screening mammography programmes across countries, as well as the comparability of screening mammography data. All countries have established mechanisms for assuring the quality of screening mammography in population-based programmes, although these mechanisms vary across countries.

Breast Neoplasms↗
PubMed2001

Long-term recreational physical activity and breast cancer in the National Health and Nutrition Examination Survey I epidemiologic follow-up study.

Our purpose was to study the association between long-term recreational physical activity and breast cancer in the Epidemiological Follow-up Study (NHEFS) of the first National Health and Nutrition Examination Survey (NHANES I, 1971-1975). The analytic cohort included 6160 women who were free of breast cancer at the first NHEFS follow-up in 1982-1984 and had interview data on recreational physical activity (low, moderate, and high) in 1982-1984 and 10 years earlier, in 1971-1975. We created categories of long-term (1982-1984 + 1971-1975) recreational physical activity: (a) consistently low; (b) moderate/inconsistent; and (c) consistently high. Data were analyzed using Cox proportional hazard regression models. A total of 138 women developed breast cancer between 1982-1984 and 1992. In women > or =50 years of age in 1982-1984, consistently high (versus consistently low) recreational physical activity was associated with a 67% reduction in breast cancer risk (n = 96 cases; relative risk, 0.33; 95% confidence interval, 0.14-0.82; P for trend = 0.03); in women <50 years of age (n = 42 cases), there was no association. Associations were not modified by body mass index or by weight gain as an adult. High recreational physical activity over the long-term may reduce breast cancer risk in women > or =50 years of age; in this sample, it did so regardless of weight history.

Adult↗
PubMed2001

Quality assurance for screening mammography data collection systems in 22 countries.

OBJECTIVES: To document the mammography data that are gathered by the organized screening programs participating in the International Breast Cancer Screening Network (IBSN), the nature of their procedures for data quality assurance, and the measures used to assess program performance and impact. METHODS: A detailed questionnaire covering multiple aspects of quality assurance in screening mammography was mailed to IBSN representatives in 23 countries. RESULTS: Countries collect a wealth of screening mammography data, much of it computerized. Most countries have designated staff for data quality assurance. All provide staff training, and most have documentation requirements for data collection. Nearly all have one or more procedures to maintain data confidentiality. Countries are heterogeneous in collecting and assessing data to monitor screening program performance and impact. CONCLUSIONS: Demonstrating that population-based screening mammography reduces breast cancer mortality requires collection of high-quality data on key aspects of the multi-step screening process. Assuring the quality of data collection systems for screening mammography programs is an important and evolving area for IBSN countries.

Breast Neoplasms↗
PubMed2000

Performance of screening mammography among women with and without a first-degree relative with breast cancer.

BACKGROUND: Although it is recommended that women with a family history of breast cancer begin screening mammography at a younger age than average-risk women, few studies have evaluated the performance of mammography in this group. OBJECTIVE: To compare the performance of screening mammography in women with a first-degree family history of breast cancer and women of similar age without such history. DESIGN: Cross-sectional. SETTING: Mammography registries in California (n = 1), New Hampshire (n = 1), New Mexico (n = 1), Vermont (n = 1), Washington State n = 2), and Colorado (n = 1). PARTICIPANTS: 389 533 women 30 to 69 years of age who were referred for screening mammography from April 1985 to November 1997. MEASUREMENTS: Risk factors for breast cancer; results of first screening examination captured for a woman by a registry; and any invasive cancer or ductal carcinoma in situ identified by linkage to a pathology database, the Surveillance, Epidemiology, and End Results program, or a state tumor registry. RESULTS: The number of cancer cases per 1000 examinations increased with age and was higher in women with a family history of breast cancer than in those without (3.2 vs. 1.6 for ages 30 to 39 years, 4.7 vs. 2.7 for ages 40 to 49 years, 6.6 vs. 4.6 for ages 50 to 59 years, and 9.3 vs. 6.9 for ages 60 to 69 years). The sensitivity of mammography increased significantly with age (P = 0.001 [chi-square test for trend]) in women with a family history and in those without (63.2% [95% CI, 41. 5% to 84.8%] vs. 69.5% [CI, 57.7% to 81.2%] for ages 30 to 39 years, 70.2% [CI, 61.0% to 79.5%] vs. 77.5% [CI, 73.3% to 81.8%] for ages 40 to 49 years, 81.3% [CI, 73.3% to 89.3%] vs. 80.2% [CI, 76.5% to 83.9%] for ages 50 to 59 years, and 83.8% [CI, 76.8% to 90.9%] vs. 87.7% [CI, 84.8% to 90.7%] for ages 60 to 69 years). Sensitivity was similar for each decade of age regardless of family history. The positive predictive value of mammography was higher in women with a family history than in those without (3.7% vs. 2.9%; P = 0.001). CONCLUSIONS: Cancer detection rates in women who had a first-degree relative with a history of breast cancer were similar to those in women a decade older without such a history. The sensitivity of screening mammography was influenced primarily by age.

Adult↗
PubMed2000

Current medicolegal and confidentiality issues in large, multicenter research programs.

The convenience of fast computers and the Internet have encouraged large collaborative research efforts by allowing transfers of data from multiple sites to a single data repository; however, standards for managing data security are needed to protect the confidentiality of participants. Through Dartmouth Medical School, in 1996-1998, the authors conducted a medicolegal analysis of federal laws, state statutes, and institutional policies in eight states and three different types of health care settings, which are part of a breast cancer surveillance consortium contributing data electronically to a centralized data repository. They learned that a variety of state and federal laws are available to protect confidentiality of professional and lay research participants. The strongest protection available is the Federal Certificate of Confidentiality, which supersedes state statutory protection, has been tested in court, and extends protection from forced disclosure (in litigation) to health care providers as well as patients. This paper describes the careful planning necessary to ensure adequate legal protection and data security, which must include a comprehensive understanding of state and federal protections applicable to medical research. Researchers must also develop rules or guidelines to ensure appropriate collection, use, and sharing of data. Finally, systems for the storage of both paper and electronic records must be as secure as possible.

Confidentiality↗
PubMed2000

Mortality among women with ductal carcinoma in situ of the breast in the population-based surveillance, epidemiology and end results program.

BACKGROUND: Over 14% of breast cancers diagnosed in the United States annually are ductal carcinomas in situ (DCIS). There are no published population-based reports of the likelihood of breast cancer death among US women with DCIS. METHODS: We used data from the Surveillance, Epidemiology and End Results program to determine the likelihood of breast cancer death at 5 and 10 years among US women aged 40 and older diagnosed with DCIS from 1978 to 1983 (before screening mammography was common; n = 1525) and from 1984 to 1989 (when screening mammography became common; n = 5547). We also calculated standardized mortality ratios (SMRs) to compare observed deaths from breast cancer, cardiovascular disease, and all causes combined among women with DCIS with deaths expected based on general population mortality rates. RESULTS: Among women diagnosed with DCIS from 1978 to 1983, 1.5% died of breast cancer within 5 years and 3.4% within 10 years. Among women diagnosed from 1984 to 1989, 0.7% died of breast cancer within 5 years and 1.9% within 10 years. Relative to the general population, risk of breast cancer death was greater for women diagnosed from 1978 to 1983 (SMR, 3.4; 95% confidence interval [CI], 2.5-4.5) than for women diagnosed from 1984 to 1989 (10-year SMR, 1.9; 95% CI, 1.5-2.3). Women diagnosed from 1984 to 1989 were significantly less likely than women in the general population to have died of cardiovascular diseases (10-year SMR, 0.6; 95% CI, 0.5-0.7) or of all causes combined (SMR, 0.8; 95% CI, 0.7-0.8). CONCLUSIONS: Among women diagnosed with DCIS, risk of death from breast cancer was low, at least within the 10 years following diagnosis. This may reflect the effectiveness of treatment for DCIS, the "benign" nature of DCIS, or both. At 10 years, women diagnosed from 1984 to 1989 were less likely than women diagnosed from 1978 to 1983 to have died of breast cancer, and their risk of dying of all causes combined was lower than that in the general population.

Adult↗
PubMed2000

Effect of variations in operational definitions on performance estimates for screening mammography.

RATIONALE AND OBJECTIVES: The Mammography Quality Standards Act requires practices to measure limited aspects of their performance. The authors conducted this study to calculate the differences in measurements of sensitivity and specificity due only to differences in the definitions used in the analysis. This included definitions for case inclusion. MATERIALS AND METHODS: Data from the New Mexico Mammography Project for January 1991 to December 1995 on 136,540 women who underwent screening mammography were analyzed. A starting definition was created for each performance measure. The components of the definition were varied, and estimates of sensitivity and specificity for the different definitions were calculated. RESULTS: Sensitivity was lower and specificity was higher when assessed on the basis of the results of all imaging performed in the screening work-up rather than on the initial screening examination alone. Sensitivity was higher and specificity was lower in women who did not undergo rather than in women who did recently undergo a previous examination. When the definition of a positive examination included cases that were recommended for short-term follow-up, the work-up sensitivity was slightly higher and the work-up specificity was considerably lower. Longer follow-up times for determining the diagnosis of cancer were associated with decreasing sensitivity, particularly when the follow-up period extended beyond 12 months. CONCLUSION: Variations in the operational definitions for measures of mammographic performance affect these estimates. To facilitate valid comparisons, reports need to be explicit regarding the definitions and methods used.

Adult↗
PubMed2000

Low energy reporters vs others: a comparison of reported food intakes.

OBJECTIVE: To partition the food reports of low energy reporters (LERs) and non-LERs into four aspects-tendency to report a given food, frequency of reports per user, portion sizes per mention, and the qualitative (low-fat, low-sugar, low-energy) differences of the reports-in order to determine what differentiates them from one another. ASSESSMENT METHOD: Two non-consecutive 24h dietary recalls. Low energy reporting was defined as energy intake lower than 80% of estimated basal metabolic rate. SETTING: In-home personal interviews. SUBJECTS: 8334 adults from a stratified, multi-stage area probability sample designed to be representative of noninstitutionlized persons residing in households in the United States. RESULTS: Across all different types of foods, there are those food groups which LERs are less likely to report (28 of 44 food groups), those which they report less frequently when they do report them (15 of 44 groups), and those for which they report smaller quantities per mention (26 of 44). Qualitative differences in the food choices-that is, differences in fat, sugar, and/or energy content-were not so widespread (4 of 24 food groups). CONCLUSIONS: The practical application of analyses such as these is to improve the methods of gathering dietary data so that this kind of bias can be reduced. Further methodological research is needed to reduce the likelihood of respondents neglecting to mention foods and underestimating portion sizes.

Adult↗