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Objectives:The National Institutes of Health (NIH) Consensus Development Conference (CDC) was instituted to provide evidence-based guidance on controversial medical issues to researchers, health practitioners, and the public; however, the degree of impact this activity has on stimulating relevant research is unclear. This study examines the impact of CDC statements on the initiation of related NIH-funded research projects.Methods:Six CDCs from 1998 to 2001 were examined. Research initiatives related to the Conferences' topics were collected through two discrete methods: (i) the overall number of relevant pre- and postconference research activities was compiled using NIH's Information for Management, Planning, Analysis, and Coordination II (IMPAC II) and the Department of Health and Human Services' (DHHS) Computer Retrieval of Information on Scientific Projects (CRISP) grant application and award databases; (ii) for each CDC, the sponsoring institute's conference coordinator and other identified Program Directors were queried for their knowledge of new conference-specific research initiatives sponsored by their institute. The main outcome measure was the total number of requests for applications, requests for proposals, program announcements, broad agency announcements, notices, and funded investigator-initiated research program grants (RO1s) for a given Consensus topic in the 3 years before (baseline measure) and following (measure of impact) a CDC.Results:As identified through NIH's IMPAC II and DHHS' CRISP grants and announcements databases, the total number of relevant postconference research initiatives increased for five of six CDCs when compared with baseline activity levels; research activities remained constant for the sixth. When inclusion criteria were restricted to institute-identified research initiatives, two of six CDC topics had overall increases in relevant research activity in the postconference period.Conclusions:CDCs appear to have a positive impact on the stimulation of related NIH-funded research initiatives. Future outcomes evaluations using prospective data collection methods and more robust participation by sponsoring and cosponsoring institutes should strengthen the reliability of the association between new research initiatives on a given topic and their causal relationship to a given CDC.

To examine obstetrician-gynecologists' knowledge, opinions, and practice patterns related to cesarean delivery on maternal request.Questionnaires were mailed to 1,031 American College of Obstetricians and Gynecologists Fellows in February 2006, with a response rate of 68%. The questionnaire queried respondents' demographic characteristics, practices and attitudes surrounding vaginal and cesarean deliveries, knowledge and beliefs regarding the risks and benefits of elective and nonelective cesarean delivery, and counseling practices and department policies for cesarean delivery on maternal request.About half of respondents believe women have the right to cesarean delivery on maternal request, and a similar percentage acknowledge having performed at least one cesarean delivery on maternal request. Fifty-eight percent of respondents note an increase in patient inquiries regarding cesarean delivery over the past year, yet most of their practices do not have a policy regarding this procedure. Respondents attribute the increase in inquiries to the increase of information from the media and to convenience. Respondents cited more risks than benefits of cesarean delivery on maternal request, and nearly all discuss these risks with patients who are considering one. Females were more negative toward cesarean delivery on maternal request than males and endorsed more risks and fewer benefits. There were no relationships between assessment of risks and benefits or practice with clinician age or patient characteristics.Most obstetrician-gynecologists in this study recognized an increased demand for cesarean delivery on maternal request within their practices, while believing that the risks of this procedure outweigh the benefits. Clinicians would benefit from strong evidence regarding risks and benefits, evidence that is crucial to guiding policy making with regard to cesarean delivery on maternal request.III.

Associations between reported consumption of animal products and chlorinated hydrocarbon concentrations were examined in 297 elderly people who lived in Germany. Consumption of beef and lamb was correlated positively with hexachlorobenzene (HCB), beta-hexachlorocyclohexane (beta-HCH), total polychlorinated biphenyls (PCBs), and total dichloro-diphenyl-trichloroethane (DDT) (r = .13-.19, p.05). Consumption of saltwater fish was correlated positively with alpha-HCH, dieldrin, and PCBs (r = .12-.26, p.05). Other univariate predictors were body mass index, plasma cholesterol, pork consumption, poultry consumption, and age. Multivariate linear models of predictors of each chlorinated species were constructed, and some form of meat was used as the main predictor; the sum of all meats (exclusive of fish) was the best predictor of dieldrin and In(alpha-HCH) concentrations. Beef and lamb consumption was a positive predictor of HCB, heptachlor epoxide, total DDT, and beta-HCH. Saltwater fish was the major dietary predictor of PCBs.

Specific congeners of PCBs may differ with respect to their human health risks. For epidemiologic studies, however, measuring levels of specific congeners—as compared with estimating the concentration of total PCBs present, may be of limited value if levels of specific congeners are highly correlated. We examined the correlations among levels of specific congeners in three groups: controls from a case-control study of breast cancer in North Carolina and two groups from Wisconsin with exposure to fish from contaminated waters. Levels of specific congeners were, in general, highly correlated (Pearson r > 0.80). However, the level of congener 180, a heptachlorobiphenyl, tended to be less correlated with levels of lower-chlorinated biphenyls. Among the implications of these findings are that measurement of a select group of congeners may yield essentially the same information as measurement of a large panel, and may be more cost efficient. Am. J. Ind. Med. 32:606–613, 1997. © 1997 Wiley-Liss, Inc.

Increased attention has focused in recent years on environmental exposures which may elevate risk of human breast cancer. Following a brief introduction to the topic, we present a summary of recent evidence regarding the role of chlorinated hydrocarbons (e.g. pesticides), occupational exposures (e.g. electromagnetic fields), dietary factors, and other hydrocarbons (e.g. tobacco). Next, we present suggestions for additional measurements which may help to clarify the contribution of environmental factors, including individual and ecologic level exposure histories, polymorphisms in carcinogen-metabolizing enzymes, and interactions among environmental exposures, breast tumor characteristics, and other risk factors for breast cancer. Finally, we discuss how a population-based approach may be used to integrate these sources of information and could provide new clues regarding the role of environmental influences in breast cancer.

In the early years of the 21st century, clinicians and medical researchers often use the term evidence-based medicine. Cancer prevention, screening, diagnosis, and therapy, we hear, must be based on the best evidence to provide the best care. But is this approach new? And if it is, what have we been doing until now? In this chapter, we hope to provide perspectives on this question, by examining what evidence-based medicine (EBM)—oncology, in particular—is and is not, and by looking at the history of clinical inquiry, up to and including current research. We also hope to provide readers with a theoretical framework that will be useful in placing the results of new research into the context of existing knowledge, with the ultimate goal of improving clinical practice.

This review discusses recent literature on the chemical and physiological factors that influence the absorption, distribution, and excretion of aluminum in mammals, with particular regard to gastrointestinal absorption and speciation in plasma. Humans encounter aluminum, a ubiquitous yet highly insoluble element in most forms, in foods, drinking water, and pharmaceuticals. Exposure also occurs by inhalation of dust and aerosols, particularly in occupational settings. Absorption from the gut depends largely on pH and the presence of complexing ligands, particularly carboxylic acids, with which the metal can form absorbable neutral aluminum species. Uremic animals and humans experience higher than normal body burdens of aluminum despite increased urinary clearance of the metal. In plasma, 80-90% of aluminum binds to transferrin, an iron-transport protein for which receptors exist in many tissue. The remaining fraction of plasma aluminum takes the form of small-molecule hydroxy species and small complexes with carboxylic acids, phosphate, and, to a much lesser degree, amino acids. Most of these species have not been observed in vivo but are predicted from equilibrium models derived from potentiometric methods and NMR investigations. These models predict that the major small-molecule aluminum species under plasma conditions are charged and hence unavailable for uptake into tissues.