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Jonathan M Samet

Publications and source records attributed to Jonathan M Samet.

72 records · Page 4Linked to original sources
PubMed2002

Commentary: what contributes to a successful career in epidemiology in the United States?

The authors conducted a study examining perceived enabling factors and barriers to a successful career in epidemiology, the role of mentoring in facilitating one's career, where graduates are most often being employed, and key competencies for future epidemiologic training. During June to August 2001, they surveyed senior epidemiologists across the United States (n = 248) in four sectors: state health departments, the Centers for Disease Control and Prevention, the National Institutes of Health, and schools of public health. The top enabling factors were dedication to hard work and having an intrinsic curiosity and a sense of discovery. The most frequently cited barrier was balancing career and family life, except among minority respondents, for whom an unsupportive supervisor was the leading obstacle. Influential characteristics of a mentor were high integrity and the provision of inspiration and encouragement. The top competencies anticipated for the next 10 years were skills working in multidisciplinary teams and in using modern information technologies. Important competencies varied somewhat according to work sector. These findings may be useful in training and career planning among aspiring epidemiologists and for educational policy development among organizations promoting training and mentoring.

Adult↗
PubMed2002

Predictors of sleep-disordered breathing in community-dwelling adults: the Sleep Heart Health Study.

BACKGROUND: Sleep-disordered breathing (SDB) is common, but largely undiagnosed in the general population. Information on demographic patterns of SDB occurrence and its predictive factors in the general population is needed to target high-risk groups that may benefit from diagnosis. METHODS: The sample comprised 5615 community-dwelling men and women aged between 40 and 98 years who were enrolled in the Sleep Heart Health Study. Data were collected by questionnaire, clinical examinations, and in-home polysomnography. Sleep-disordered breathing status was based on the average number of apnea and hypopnea episodes per hour of sleep (apnea-hypopnea index [AHI]). We used multiple logistic regression modeling to estimate cross-sectional associations of selected participant characteristics with SDB defined by an AHI of 15 or greater. RESULTS: Male sex, age, body mass index, neck girth, snoring, and repeated breathing pause frequency were independent, significant correlates of an AHI of 15 or greater. People reporting habitual snoring, loud snoring, and frequent breathing pauses were 3 to 4 times more likely to have an AHI of 15 or greater vs an AHI less than 15, but there were weaker associations for other factors with an AHI of 15 or greater. The odds ratios (95% confidence interval) for an AHI of 15 or greater vs an AHI less than 15 were 1.6 and 1.5, respectively, for 1-SD increments in body mass index and neck girth. As age increased, the magnitude of associations for SDB and body habitus, snoring, and breathing pauses decreased. CONCLUSIONS: A significant proportion of occult SDB in the general population would be missed if screening or case finding were based solely on increased body habitus or male sex. Breathing pauses and obesity may be particularly insensitive for identifying SDB in older people. A better understanding of predictive factors for SDB, particularly in older adults, is needed.

Adult↗
PubMed2002

Temperature and mortality in 11 cities of the eastern United States.

Episodes of extremely hot or cold temperatures are associated with increased mortality. Time-series analyses show an association between temperature and mortality across a range of less extreme temperatures. In this paper, the authors describe the temperature-mortality association for 11 large eastern US cities in 1973-1994 by estimating the relative risks of mortality using log-linear regression analysis for time-series data and by exploring city characteristics associated with variations in this temperature-mortality relation. Current and recent days' temperatures were the weather components most strongly predictive of mortality, and mortality risk generally decreased as temperature increased from the coldest days to a certain threshold temperature, which varied by latitude, above which mortality risk increased as temperature increased. The authors also found a strong association of the temperature-mortality relation with latitude, with a greater effect of colder temperatures on mortality risk in more-southern cities and of warmer temperatures in more-northern cities. The percentage of households with air conditioners in the south and heaters in the north, which serve as indicators of socioeconomic status of the city population, also predicted weather-related mortality. The model developed in this analysis is potentially useful for projecting the consequences of climate-change scenarios and offering insights into susceptibility to the adverse effects of weather.

Climate↗
PubMed2002

Associations of weight, weight change, and body mass with breast cancer risk in Hispanic and non-Hispanic white women.

PURPOSE: A wealth of studies have examined the effects of weight, weight gain, and obesity on breast cancer risk; however, few have examined this relationship in Hispanic white women, a population with the highest rate of obesity in the U.S. METHODS: A population-based case-control study was conducted in New Mexico of Hispanic (n = 694) and non-Hispanic (n = 813) white women with incident breast cancer during the period of January 1, 1992 through December 31, 1994. Conditional logistic regression models were fitted to estimate the relative risk of breast cancer for levels of weight, weight change, and body mass index (BMI) and to assess differences in the effects by ethnicity, menopausal status, early life BMI, and estrogen receptor/progesterone receptor (ER/PR) expression in tumors. RESULTS: Weight change from age 18 to usual adult weight was associated with increased risk of breast cancer among Hispanics [4th quartile vs. baseline, odds ratio (OR): 2.41; 95% confidence interval (CI): 1.45-4.03] with no substantial variation by menopausal status. In non-Hispanic white women, weight change was a risk factor for those in the post-menopausal group (4th quartile vs. baseline, OR: 2.27; 95% CI: 1.09-4.73). The effect of usual BMI (test for interaction p = 0.04) and weight change (test for interaction p = 0.03) differed by ethnicity. Increased risk from weight gain was largely restricted to women who were lean at age 18 and those with ER(+)/PR(+) tumors. Height, weight at age 18, and BMI at age 18 were not associated with risk in either ethnic group. CONCLUSIONS: Weight change and obesity are risk factors for breast cancer in both Hispanic and non-Hispanic white women. However, the risk for Hispanic women is evident independent of menopausal status, while the risk for non-Hispanics is apparent in post-menopausal women. Due to the increasing prevalence of adult obesity, particularly among Hispanic women, adult weight gain may be an important modifiable risk factor for the primary prevention of breast cancer among Hispanic populations.

Adult↗
PubMed2002

A comparison of three comorbidity indexes in a head and neck cancer population.

We explored differences in prognostic ability for mortality of the established and validated Charlson comorbidity index with two other comorbidity indexes developed for this study. Our study was limited to persons diagnosed with HNCA between 1985 and 1993 in a database formed by a linkage of files from the National Cancer Institute's Surveillance, Epidemiology, and End Results Program with Health Care Finance Administration Medicare files (n=9386). Adjusted relative risks (RR) and 95% confidence intervals (95%CI) for comorbidity index scores of 1 or more compared to 0 were (RR=1.50, 95% CI 1.43-1.68) Charlson index, (RR=1.53 95% CI 1.42-1.66) HNCA index, and (RR=1.49, 95% CI 1.32-1.68) ATC index, respectively. The Charlson and HNCA indexes displayed dose-response patterns (P-value for trend <0.0001). Although the ATC index appears promising, the HNCA and Charlson indexes had similar adjusted RR's, dose-response patterns, P-values, and chi-square scores and appear particularly well-suited to the measurement of comorbidity.

Aged↗
PubMed2002

Outdoor air pollution and acute respiratory infections among children in developing countries.

Acute respiratory infections (ARIs) are the most common cause of illness and death in children in the developing world. This review focuses on outdoor air pollutants associated with pediatric ARI mortality and morbidity. Studies were identified using MEDLINE and other electronic databases. Four studies showed an increase in infant mortality in relation to outdoor air pollution. Short-term follow-up and time-series studies suggest that air pollutants act as risk factors for respiratory infection. Air pollution exposure increases the incidence of upper- and lower-respiratory infections in children. Because complex pollution mixtures are present in the studied urban areas, pollutant levels at which ARI risk would be expected to increase cannot be determined. Children may be at greater risk, given the poor environmental and nutritional conditions prevalent in developing countries.

Acute Disease↗
PubMed2002

An exposure assessment study of ambient heat exposure in an elderly population in Baltimore, Maryland.

Because of concern for heat-related mortality in vulnerable populations, particularly the elderly, practical epidemiologic methods are needed for the assessment of ambient heat exposure on individuals. We used a personal monitor to measure body temperature, ambient temperature, heart rate, and activity level of 42 elderly residents of Baltimore, Maryland, in the summer months of 2000. Each participant was monitored for approximately 48 hr to examine the association between ambient temperature and body temperature, using regression methods that account for highly correlated data within individuals. We also examined the associations of Baltimore temperature data with personal ambient temperature and body temperature. An average 0.15 degrees F [95% confidence interval (CI), 0.05-0.25] increase in median body temperature was found for each 1 degrees F increase in median ambient temperature. Heart rate and activity level were not found to be related to body temperature or ambient temperature, although heart rate was associated with activity level. Median heart rate increased an average of 0.17 (95% CI, 0.13-0.21) beats per minute for every unit increase in median activity level. Personal ambient temperature was slightly lower than Baltimore temperatures, whereas an association was not found between body temperature and Baltimore temperatures. The protocol established in this study for heat exposure assessment could feasibly be applied on a larger scale.

Aged↗
PubMed2002

Is alcohol intake associated with breast cancer in Hispanic women? The New Mexico Women's Health Study.

OBJECTIVE: Previous studies have shown an increased breast cancer risk associated with modest or high alcohol intake, however, few of these studies have included Hispanic women. The alcohol/breast cancer association was investigated in a New Mexico (NM) statewide bi-ethnic study. DESIGN: A population-based, case-control study. METHODS: Incident breast cancer cases (N = 712), aged 30-74 years, were ascertained by the New Mexico Tumor Registry (NMTR). Controls (N = 844) were identified by random digit dialing and were frequency-matched for ethnicity, age-group, and health planning district. Data were collected via in-person interview, which included questions regarding recent and past alcohol intake and breast cancer risk factors. RESULTS: The highest level of recent alcohol intake, compared to no intake, was associated with breast cancer risk for postmenopausal Hispanic women (odds ratio [OR] = 2.0 95%, confidence interval [CI] 0.8-5.1, 42+ grams/ week) and postmenopausal non-Hispanic White women (OR = 2.2, 95% Cl 1.0-5.0, 148+ grams/week), although estimates were unstable and statistically non-significant. Lower recent alcohol intake (< 148 grams/week) was associated with reduced risk for non-Hispanic Whites (OR = 0.49, 95% Cl 0.35-0.69). This pattern was independent of hormone-receptor status and was present for both premenopausal (OR = 0.29, 95% Cl 0.15-0.56) and postmenopausal women (OR = 0.56, 95% Cl 0.35-0.90). Results for past alcohol intake and breast cancer association did not demonstrate any trends and were non-significant. CONCLUSIONS: Alcohol intake does not appear to have a consistent or significant association with breast cancer in Hispanic women.

Adult↗
PubMedDate not supplied

The perspective of the National Research Council's Committee on Research Priorities for Airborne Particulate Matter.

This article summarizes the activities of the National Research Council Committee on Research Priorities for Airborne Particulate Matter, formed in 1997 in response to a request by Congress to establish a committee that would identify research needs, set a research agenda, and monitor research progress on airborne particulate matter. The article describes the committee's achievements and research progress in relation to key scientific questions relevant to establishing National Ambient Air Quality Standards (NAAQS).

Air Pollutants↗
PubMedDate not supplied

Revised analyses of the National Morbidity, Mortality, and Air Pollution Study: mortality among residents of 90 cities.

This article presents findings from updated analyses of data from 90 U.S. cities assembled for the National Morbidity, Mortality, and Air Pollution Study (NMMAPS). The data were analyzed with a generalized additive model (GAM) using the gamfunction in S-Plus (with default convergence criteria previously used and with more stringent criteria) and with a generalized linear model (GLM) with natural cubic splines. With the original method, the estimated effect of PM(10) (particulate matter 10 microm in mass median aerodynamic diameter) on total mortality from nonexternal causes was a 0.41% increase per 10-microg/m(3) increase in PM(10); with the more stringent criteria, the estimate was 0.27%; and with GLM, the effect was 0.21%. The effect of PM(10) on respiratory and cardiovascular mortality combined was greater, but the pattern across models was similar. The findings of the updated analysis with regard to spatial heterogeneity across the 90 cities were unchanged from the original analyses.

Air Pollution↗
PubMedDate not supplied

The global burden of disease due to outdoor air pollution.

As part of the World Health Organization (WHO) Global Burden of Disease Comparative Risk Assessment, the burden of disease attributable to urban ambient air pollution was estimated in terms of deaths and disability-adjusted life years (DALYs). Air pollution is associated with a broad spectrum of acute and chronic health effects, the nature of which may vary with the pollutant constituents. Particulate air pollution is consistently and independently related to the most serious effects, including lung cancer and other cardiopulmonary mortality. The analyses on which this report is based estimate that ambient air pollution, in terms of fine particulate air pollution (PM(2.5)), causes about 3% of mortality from cardiopulmonary disease, about 5% of mortality from cancer of the trachea, bronchus, and lung, and about 1% of mortality from acute respiratory infections in children under 5 yr, worldwide. This amounts to about 0.8 million (1.2%) premature deaths and 6.4 million (0.5%) years of life lost (YLL). This burden occurs predominantly in developing countries; 65% in Asia alone. These estimates consider only the impact of air pollution on mortality (i.e., years of life lost) and not morbidity (i.e., years lived with disability), due to limitations in the epidemiologic database. If air pollution multiplies both incidence and mortality to the same extent (i.e., the same relative risk), then the DALYs for cardiopulmonary disease increase by 20% worldwide.

Air Pollutants↗
PubMedDate not supplied

Report of workshop on traffic, health, and infrastructure planning.

Recent air pollutant measurement data document unique aspects of the air pollution mixture near roadways, and an expanding body of epidemiological data suggests increased risks for exacerbation of asthma and other respiratory diseases, premature mortality, and certain cancers and birth outcomes from air pollution exposures in populations residing in relatively close proximity to roadways. The Workshop on Traffic, Health, and Infrastructure Planning, held in February 2004, was convened to provide a forum for interdisciplinary discussion of motor vehicle emissions, exposures and potential health effects related to proximity to motor vehicle traffic. This report summarizes the workshop discussions and findings regarding the current science on this issue, identifies planning and policy issues related to localized motor vehicle emissions and health concerns, and provides recommendations for future research and policy directions.

Air Pollution↗