ISSN:1044-3983    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:1044-3983    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:1044-3983    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

The Women's Interagency HIV Study comprises the largest U.S. cohort to date of human immunodeficiency virus (HIV)-seropositive women (N = 2,058) with a comparison cohort of seronegative women (N = 568). The methodology, training, and quality assurance activities employed are described. The study population, enrolled between October 1994 and November 1995 through six clinical consortia throughout the United States (totaling 23 sites) represents a typically hard-to-reach study population. More than half of the women in each cohort were living below the federally defined levels of poverty. The women ranged in age from 16 to 73 years; approximately one-quarter self-identified as Latina or Hispanic, over one-half as African-American not of Hispanic origin, and less than 20% as white, non-Hispanic origin. Self-reporting of HIV exposure risk included injection drug use by 34% of the seropositive women and 28% of the seronegative women, heterosexual contact (42%vs26%), transfusion risk (4%vs3%) and no identified risk (20%vs43%). Demographic and HIV exposure risk characteristics of the seropositive cohort were comparable with characteristics of nationally reported AIDS cases in U.S. women. This well characterized cohort of HIV-seropositive and high-risk seronegative women represents a rich opportunity for future studies of HIV disease progression and pathogenesis.

ISSN:1044-3983    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

In 1992, we published four retrospective studies, conducted primarily within a single California county, which found higher spontaneous abortion rates among women who drank more tapwater than bottled water in early pregnancy. The current prospective study extends that investigation to other water systems. Pregnant women from three regions in California were interviewed during their first trimester. Multivariate analyses modeled the amount and type of water consumed at 8 weeks' gestation in each region in relation to spontaneous abortion rate. In Region I, which was within the previous study area, the adjusted odds ratio (OR) comparing high (≥6 glasses per day) consumption of cold tapwater with none was 2.17 [95% confidence interval (CI) = 1.22–3.87]. Furthermore, when women with high cold tapwater and no bottled water consumption were compared with those with high bottled water and no cold tapwater consumption, the adjusted odds ratio was 4–58 (95% CI = 1.97–10.64). Conversely, women with high bottled water consumption and no tapwater had a reduced rate of spontaneous abortion compared with those drinking tapwater and no bottled water (adjusted OR = 0.22; 95% CI = 0.09–0.51). Neither tap nor bottled water consumption altered the risk of spontaneous abortion in Regions II and III. Although controlling for age, prior spontaneous abortion, race, gestational age at interview, and weight somewhat strengthened the association in Region I, the distribution of these confounders did not vary appreciably across regions. This study confirms the association between cold tapwater and spontaneous abortion first seen in this county in 1980. If causal, the agent(s) is not ubiquitous but is likely to have been present in Region I for some time.

ISSN:1044-3983    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Trihalomethanes (chloroform, bromoform, bromodichlo-romethane, and chlorodibromomethane) are common contaminants of chlorinated drinking water. Although animal data indicate that these compounds may be reproductive toxicants, little information exists on their relation to spontaneous abortion in humans. We examined exposure to trihalomethanes and spontaneous abortion in a prospective study of 5,144 pregnant women in a prepaid health plan. Seventy-eight drinking water utilities provided concurrent trihalomethane sampling data. We calculated total trihalomethane levels by averaging all measurements taken by the subject's utility during her first trimester. We calculated exposures to individual trihalomethanes in an analogous manner. Women who drank ≥5 glasses per day of cold tapwater containing ≥75 μg per liter total trihalomethanes had an adjusted odds ratio (OR) of 1.8 for spontaneous abortion [95% confidence interval (CI) = 1.1–3.0]. Of the four individual trihalomethanes, only high bromodichloromethane exposure (consumption of ≥5 glasses per day of cold tapwater containing ≥18 μg per liter bromodichloromethane) was associated with spontaneous abortion both alone (adjusted OR = 2.0; 95% Cl = 1.2–3.5) and after adjustment for the other trihalomethanes (adjusted OR = 3.0; 95% CI = 1.4–6.6).

ISSN:1044-3983    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

To quantify the risk of severe anaphylaxis due to drugs and other exposures in hospital patients, a study of incident cases has been in progress since 1992, with data collection in Hungary, Spain, India, and Sweden. All cases of anaphylaxis that develop after admission to participating hospitals are enrolled. To confirm the diagnosis, clinical information for potential cases is reviewed by two physicians without knowledge of exposures, according to an algorithm developed for the study. Confirmed cases are classified as definite, probable, or possible anaphylaxis. As of March 1995, 123 cases were enrolled in Budapest, Barcelona, and Bombay/Pune (the study began in January 1996 in Sweden): 99 were classified as definite or probable anaphylaxis, and 24 as possible. Two of the 123 cases were fatal (2%). Based on the definite and probable cases and a denominator of 481,752 individuals in the nine participating institutions for which the age and sex distribution was known, we estimated the overall risk of severe anaphylaxis to be 154 per million hospital admissions; when the possible cases were included, the risk was 196 per million. The risk was higher among women, and it varied, although not linearly, according to age. A major problem in the epidemiologic evaluation of anaphylaxis has been resolved in the present study with the development of a case definition that, contrary to usual clinical practice, is independent of exposure. The results thus far indicate that severe anaphylaxis occurs infrequently among hospitalized patients and is rarely fatal.

ISSN:1044-3983    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Differential mortality exists in the United States both between racial/ethnic groups and along gradients of socioeconomic status. The specification of statistical models for processes underlying these observed disparities has been hindered by the fact that social and economic quantities are distributed in a highly nonrandom manner throughout the population. We sought to provide a substantive foundation for model development by representing the shape of the income-mortality relation by racial/ethnic group.We used data on black and white men and women from the longitudinal component of the National Health Interview Survey (NHIS), 1986–1990, which provided 1,191,824 person-years of follow-up and 12, 165 mortal events. To account for family size when considering income, we used the ratio of annual family income to the federal poverty line for a family of similar composition.To avoid unnecessary categorizations and prior assumptions about model form, we employed kernel smoothing techniques and calculated the continuous mortality surface across dimensions of adjusted income and age for each of the gender and racial/ethnic groups. Representing regions of equal mortality density with contour plots, we observed interactions that need to be accommodated by any subsequent statistical models. We propose two general theories that provide a foundation for more elaborate and testable hypotheses in the future.

ISSN:1044-3983    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Some studies indicate that chlorination by-products in drinking water may contribute slightly to breast cancer risk. This ecologic study describes the association between total trihalomethane levels in publicly supplied water and the incidence of female invasive breast cancer. We included 71 North Carolina water suppliers serving at least 10,000 customers in the summer of 1995 as the units of analysis. We estimated incidence rates using 6,462 cases who were either white or black and between 35 and 84 years old and were linked by zip codes to the water supplier. We treated ecologic measurements of age, income, education, urban status, and race as potential confounders. Total trihalomethane levels were not associated materially with breast cancer risk, adjusting for potential confounders. The rate ratio for 80.0 parts per billion (ppb) or morevsless than 40.0 ppb total trihalomethanes was 1.1 [95% confidence interval (CI) = 0.9–1.2]. When stratified by race, the observed association for the aforementioned total trihalomethane category was not very different in black women (rate ratio = 1.2; 95% CI = 0.8–1.8) than in white women (rate ratio = 1.1; 95% CI = 0.9–1.3). These ecologic data are compatible with trihalomethanes in drinking water being either unrelated or weakly related to breast cancer risk.

ISSN:1044-3983    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

We studied paternal exposure to Agent Orange and its dioxin contaminant (2,3,7,8-tetrachlorodibenzo-p-dioxin) and preterm birth, intrauterine growth retardation, or infant death in veterans of Operation Ranch Hand, the unit responsible for spraying herbicides during the Vietnam war. A Comparison group of Air Force veterans who served in Southeast Asia during the same time period and who were not occupationally exposed to herbicides was included. We studied children conceived during or after the father's service in Southeast Asia and based exposure on paternal dioxin measured in 1987 or 1992 extrapolated to the time of conception of the child. We assigned each child to one of four exposure categories: Comparison and three Ranch Hand categories (Background, Low, High). Children in the High (relative risk =1.3) and Background (relative risk = 1.4) categories were at increased risk of preterm birth. The risk of intrauterine growth retardation was not increased in any exposure category. The risk of infant death was increased in all Ranch Hand children, with the greatest increases in the High (relative risk = 4.5) and Background (relative risk = 3.2) categories. These patterns indicate that the increases in the relative risk of preterm birth and infant death may not be related to paternal dioxin level.

ISSN:1044-3983    

出版商:OVID    

年代:1998

数据来源: OVID