Search

Background Because smallpox (variola major) may be used as a biological weapon, we reviewed outbreaks in post-World War II Europe and North America in order to understand smallpox transmission patterns. Methods A systematic review was used to identify papers from the National Library of Medicine, Embase, Biosis, Cochrane Library, Defense Technical Information Center, WorldCat, and reference lists of included publications. Two authors reviewed selected papers for smallpox outbreaks. Results 51 relevant outbreaks were identified from 1,389 publications. The median for the effective first generation reproduction rate (initial R) was 2 (range 0–38). The majority outbreaks were small (less than 5 cases) and contained within one generation. Outbreaks with few hospitalized patients had low initial R values (median of 1) and were prolonged if not initially recognized (median of 3 generations); outbreaks with mostly hospitalized patients had higher initial R values (median 12) and were shorter (median of 3 generations). Index cases with an atypical presentation of smallpox were less likely to have been diagnosed with smallpox; outbreaks in which the index case was not correctly diagnosed were larger (median of 27.5 cases) and longer (median of 3 generations) compared to outbreaks in which the index case was correctly diagnosed (median of 3 cases and 1 generation). Conclusion Patterns of spread during Smallpox outbreaks varied with circumstances, but early detection and implementation of control measures is a most important influence on the magnitude of outbreaks. The majority of outbreaks studied in Europe and North America were controlled within a few generations if detected early.

Objectives. We evaluated perceptions of workers at the US Postal Service Brentwood Processing and Distribution Center and US Senate employees regarding public health responses to the anthrax mailings of October 2001. We generated recommendations for improving responses to bioterrorism on the basis of the perceptions we recorded. Methods. Transcripts from focus groups conducted with Brentwood and US Senate employees were examined, and qualitative analysis identified common domains. Results. Brentwood focus groups consisted of 36 participants (97% African American and 19% hearing impaired). US Senate focus groups consisted of 7 participants (71% White and 0% hearing impaired). The focus groups revealed that participants’ trust in public health agencies had eroded and that this erosion could threaten the effectiveness of communication during future public health emergencies. Among Brentwood participants, lack of trust involved the perception that unfair treatment on the basis of race/ethnicity and socioeconomic status had occurred; among US Senate participants, it derived from perceptions of inconsistent and disorganized messages. Conclusions. Effective communication during a public health emergency depends on the provision of clear messages and close involvement of the affected community. Diverse populations may require individualized approaches to ensure that messages are delivered appropriately. Special attention should be given to those who face barriers to traditional modes of communication.

To prevent significant loss of life in the event of a smallpox bioterrorist attack, should smallpox vaccination be reintroduced?

Objective To address methodologic issues in searching for observational studies by presenting database search methods and results. Study Design and Setting Results of two literature searches for publications reporting on observational studies of alcohol consumption and the risk of breast cancer and large bowel cancer were compared, to evaluate the sensitivity of various bibliographic databases and search strategies, including hand-searching reviews and meta-analyses. Results The target sensitivity of 90% of publications in the breast cancer search was achieved by starting with Medline, then adding Biosis, Embase, and SCI EXPANDED–SSCI, which provided a total of 72 (91%) of the 79 relevant publications. To reach a similar 89% sensitivity for large bowel cancer, at least Biosis, Dissertation Abstracts Online, Embase, ETOH, and Medline had to be searched, with the addition of hand search of reviews and meta-analyses. Conclusion Limiting a search to one or two databases when conducting meta-analyses of observational studies will not provide a thorough summary of the existing literature. The findings support recommendations to implement a comprehensive search of electronic databases and the reference lists of recent review articles and meta-analyses.

Two examples-the "swine flu affair" in 1976 and the emergence of HIV in the blood supply in the early 1980s-illustrate the difficulties of decision-making in public health. Both cases illustrate trade-offs between product risks and public health benefits, especially with regard to uncertainty in estimates of product risks, public health risks, and the benefits of prevention. The cases also illustrate the tendency of public health policy makers to go all the way or do nothing at all, rather than consider intermediate options that can be adapted as new information emerges. This review suggests three lessons for public health policy makers: (1) be open and honest about scientific uncertainty; (2) communicate with the public, even when the facts are not clear; and (3) consider intermediate, adaptable policy options, such as obtaining more information, thus reducing uncertainty, and building in decision points to reconsider initial policies. Underlying all of these lessons is the need to commission studies to resolve important uncertainties and increase the information base for public communication, and to review regulations and other policy options in the light of the new data that emerge.

This paper is a summary of a panel discussion at the Conference on Epidemiology and Demography held at Georgetown University, in Washington D.C. on February 8-9, 2001. The participants were Al Hermalin, Linda Martin, Mike Stoto, Robert Wallace, Douglas Weed, and Rose Li (who chaired the session). A list of questions similar to the section headings in this paper was prepared in advance of the conference, and each of the participants was asked to address specific issues, although the presentations typically covered a range of topics. This summary also includes comments from the floor.

Environmental scientists play a key role in society's responses to environmental problems, and many of the studies they perform are intended ultimately to affect policy. The precautionary principle, proposed as a new guideline in environmental decision making, has four central components: taking preventive action in the face of uncertainty; shifting the burden of proof to the proponents of an activity; exploring a wide range of alternatives to possibly harmful actions; and increasing public participation in decision making. In this paper we examine the implications of the precautionary principle for environmental scientists, whose work often involves studying highly complex, poorly understood systems, while at the same time facing conflicting pressures from those who seek to balance economic growth and environmental protection. In this complicated and contested terrain, it is useful to examine the methodologies of science and to consider ways that, without compromising integrity and objectivity, research can be more or less helpful to those who would act with precaution. We argue that a shift to more precautionary policies creates opportunities and challenges for scientists to think differently about the ways they conduct studies and communicate results. There is a complicated feedback relation between the discoveries of science and the setting of policy. While maintaining their objectivity and focus on understanding the world, environmental scientists should be aware of the policy uses of their work and of their social responsibility to do science that protects human health and the environment. The precautionary principle highlights this tight, challenging linkage between science and policy.

Prevention is about saving "statistical lives"-lives that society knows about only through the efforts of public health statisticians like Jack Smith. As Mr. Smith's lifework suggests, statistics in public health are critical for calling attention to problems, identifying risk factors, and suggesting solutions, and ultimately for taking credit for our successes. His work illustrates two important lessons about public health statistics today.First, it's important to get the facts straight. Mr. Smith's experience shows that a careful, thoughtful analysis is not only more convincing in the end, but also brings to light important subtleties not seen in the initial analysis. Second, it takes considerable time and attention to get the facts straight. Jack Smith's work illustrates the importance of partnerships with other federal agencies, state statistical organizations, and private-sector entities.

Improving Health in the Community , Improving Health in the Community , کتابخانه الکترونیک و دیجیتال - آذرسا

Background School closure was employed as a non-pharmaceutical intervention against pandemic 2009 H1N1, particularly during the first wave. More than 700 schools in the United States were closed. However, closure decisions reflected significant variation in rationales, decision triggers, and authority for closure. This variability presents the opportunity for improved efficiency and decision-making. Methods We identified media reports relating to school closure as a response to 2009 H1N1 by monitoring high-profile sources and searching Lexis-Nexis and Google news alerts, and reviewed reports for key themes. News stories were supplemented by observing conference calls and meetings with health department and school officials, and by discussions with decision-makers and community members. Results There was significant variation in the stated goal of closure decision, including limiting community spread of the virus, protecting particularly vulnerable students, and responding to staff shortages or student absenteeism. Because the goal of closure is relevant to its timing, nature, and duration, unclear rationales for closure can challenge its effectiveness. There was also significant variation in the decision-making authority to close schools in different jurisdictions, which, in some instances, was reflected in open disagreement between school and public health officials. Finally, decision-makers did not appear to expect the level of scientific uncertainty encountered early in the pandemic, and they often expressed significant frustration over changing CDC guidance. Conclusions The use of school closure as a public health response to epidemic disease can be improved by ensuring that officials clarify the goals of closure and tailor closure decisions to those goals. Additionally, authority to close schools should be clarified in advance, and decision-makers should expect to encounter uncertainty disease emergencies unfold and plan accordingly.

See the original Letter to the Editor, [p. 1046][1] Edwards-Bennett raises an interesting issue about the need to include disparities in utilization of adjuvant breast cancer radiation therapy (RT) in models to explain differences in mortality by race. In our study, we found that differences in

In 1990, the Secretary of Health and Human Services unveiled Healthy People 2000: National Health Promotion and Disease Prevention Objectives (46), which is a milestone in public health. Healthy People 2000 identifies three national health goals: increase the span of healthy life, reduce health disparities among Americans, and achieve access to preventive services for all Americans. The report also details 300 specific objectives for health promo­ tion and disease prevention programs with quantitative targets to be achieved by the year 2000. Meeting these objectives requires agreement by public health statisticians on measures of individual and community health status to guide public health policy development and priorities, especially for state and .local areas, and improvement in the methods, for tracking these measures. Healthy People 2000 challenges public health practitioners to develop surveillance systems that are both meaningful in a public health sense and statistically sound. To clarify this challenge and outline some possible re­ sponses, I begin with some background on the public health assessment activities on which the year 2000 health objectives build and considerations that should guide public health assessment efforts. The next section presents general statistical issues in formulating measurable and meaningful objec­ tives. Other sections are devoted to two specific issues: the development of a small set of health status indicators that is both meaningful and feasible to monitor and special issues associated with setting objectives and determining appropriate targets for state and local areas.

Background Since 2001, the District of Columbia Department of Health has been using an emergency room syndromic surveillance system to identify possible disease outbreaks. Data are received from a number of local hospital emergency rooms and analyzed daily using a variety of statistical detection algorithms. The aims of this paper are to characterize the performance of these statistical detection algorithms in rigorous yet practical terms in order to identify the optimal parameters for each and to compare the ability of two syndrome definition criteria and data from a children's hospital versus vs. other hospitals to determine the onset of seasonal influenza. Methods We first used a fine-tuning approach to improve the sensitivity of each algorithm to detecting simulated outbreaks and to identifying previously known outbreaks. Subsequently, using the fine-tuned algorithms, we examined (i) the ability of unspecified infection and respiratory syndrome categories to detect the start of the flu season and (ii) how well data from Children's National Medical Center (CNMC) did versus all the other hospitals when using unspecified infection, respiratory, and both categories together. Results Simulation studies using the data showed that over a range of situations, the multivariate CUSUM algorithm performed more effectively than the other algorithms tested. In addition, the parameters that yielded optimal performance varied for each algorithm, especially with the number of cases in the data stream. In terms of detecting the onset of seasonal influenza, only "unspecified infection," especially the counts from CNMC, clearly delineated influenza outbreaks out of the eight available syndromic classifications. In three of five years, CNMC consistently flags earlier (from 2 days up to 2 weeks earlier) than a multivariate analysis of all other DC hospitals. Conclusions When practitioners apply statistical detection algorithms to their own data, fine tuning of parameters is necessary to improve overall sensitivity. With fined tuned algorithms, our results suggest that emergency room based syndromic surveillance focusing on unspecified infection cases in children is an effective way to determine the beginning of the influenza outbreak and could serve as a trigger for more intensive surveillance efforts and initiate infection control measures in the community.

Despite trials of mammography and widespread use, optimal screening policy is controversial.To evaluate U.S. breast cancer screening strategies.6 models using common data elements.National data on age-specific incidence, competing mortality, mammography characteristics, and treatment effects.A contemporary population cohort.Lifetime.Societal.20 screening strategies with varying initiation and cessation ages applied annually or biennially.Number of mammograms, reduction in deaths from breast cancer or life-years gained (vs. no screening), false-positive results, unnecessary biopsies, and overdiagnosis.The 6 models produced consistent rankings of screening strategies. Screening biennially maintained an average of 81% (range across strategies and models, 67% to 99%) of the benefit of annual screening with almost half the number of false-positive results. Screening biennially from ages 50 to 69 years achieved a median 16.5% (range, 15% to 23%) reduction in breast cancer deaths versus no screening. Initiating biennial screening at age 40 years (vs. 50 years) reduced mortality by an additional 3% (range, 1% to 6%), consumed more resources, and yielded more false-positive results. Biennial screening after age 69 years yielded some additional mortality reduction in all models, but overdiagnosis increased most substantially at older ages.Varying test sensitivity or treatment patterns did not change conclusions.Results do not include morbidity from false-positive results, patient knowledge of earlier diagnosis, or unnecessary treatment.Biennial screening achieves most of the benefit of annual screening with less harm. Decisions about the best strategy depend on program and individual objectives and the weight placed on benefits, harms, and resource considerations.National Cancer Institute.

BACKGROUND. The national objectives in Healthy People 2000, drafted by health professionals aware of currently available public health interventions, represent a wealth of information about near-term future mortality and morbidity. METHODS. Life table methods were used to calculate the impact of projected changes in mortality and activity limitation rates on life expectancy and expected disability years. RESULTS. Meeting the mortality objectives would increase life expectancy at birth by 1.5 to 2.1 years, raising life expectancy to 76.6 to 77.2 years. In addition, meeting the target for disability from chronic conditions would increase the number of years of life without activity limitations from 66.8 years to 69.3-69.7 years. If the targets for coronary heart disease and unintentional injury were changed to reflect recent trends, a greater improvement in life expectancy at birth would be achieved: from 1.8 to 2.7 years to 76.9 to 77.8 years. CONCLUSION. Meeting the targets would have an important demographic impact. Including changes in the coronary heart disease and injuries targets, life expectancy in the year 2000 would be above the middle of the ranges used in current Census Bureau projections.

To the Editor. As we move into the third millennium, acute rheumatic fever (ARF) appears to be a vanishing disease in the United States. However, conflicting reports regarding the incidence of ARF have been published during the past decade.1–3 Veasy et al1continue to see 20 or more new patients/year with ARF. We would like to support Veasy's observations, and note that 30 to 50 …

The authors report on a 1992 workshop convened to discuss ways to more accurately forecast mortality morbidity and disability in the United States. "Workshop discussions supported use of medium-term forecasts produced by a statistical model by Lee and Carter; qualitative adjustments should be made on the basis of medical and biological knowledge about forces likely to affect mortality." The article also includes "suggestions about further development of aggregate statistical projection models and other statistical issues about the development of models of specific diseases and causes of death and about other research needs." (SUMMARY IN FRE AND SPA) (EXCERPT)

One of the critical policy questions raised by the AIDS epidemic is the proper size of the United States federal government's commitment to AIDS-related research. The extent of the federal government's investment in AIDS-related research in relation to research investments in cancer, coronary heart disease, and unintentional injuries is examined. Appropriation levels for fiscal year 1986 are divided by indexes of projected disease burden for 1991 to create a research investment ratio for each health impairment. Indexes of disease burden include numbers of total deaths, early deaths, expected life years lost, and discounted life years lost and direct economic costs. Despite the uncertainty about the future of the AIDS epidemic, there is no indication that AIDS is being overfunded relative to cancer and heart disease. Injuries appear to receive relatively low funding priority. Confident conclusions about research priority depend upon resolution of qualitative considerations and better understanding of the dynamics of the AIDS epidemic.

Growth in the industrial support of university research in the life sciences and more specifically in biotechnology has raised questions concerning its effects, both positive and negative, on the educational experiences of graduate students and post-doctoral fellows. A survey of 693 graduate students and post-doctoral fellows at six research intensive universities in the United States reveals that 19 percent of the responding students and fellows receive direct industry support for their research or training and that another 15 percent work with faculty advisors supported by industrial funds. On average students and fellows in this sample believe that the benefits of relationships with private firms outweigh the risks. In addition, students funded by private firms are more likely than those without industry connections to report patents resulting from their research. No relationship is found between industry support and young scientists' career plans or their rating of the quality of their educational experiences. However, the data suggest the existence of some risks: industry support is associated with fewer or delayed publications, inhibition of scientific communication on the part of some trainees, and some restrictions on students' and fellows' research. In a few cases, students are supported by funds from companies in which faculty advisors hold equity, a situation that creates potential conflicts of interest for students' mentors. To protect students, university administrators must monitor the relationships with industry that give rise to these potential problems. Future research into industrial support of research and training is needed to extend these results.

"This report contains recommendations reflecting the views of the ASA Technical Panel on the Census Undercount concerning [U.S.] Census Bureau procedures and plans in the fall of 1982." The report consists of technical statistical advice on measurement and estimation problems. A response by Barbara A. Bailar, reflecting the views of the U.S. Census Bureau, is also included (pp. 257-60).

Since the seminal work of Brass and Coale demographers have become highly skilled in the estimation of demographic parameters from indirect data. In many developing countries the classical sources of demographic data--registration of vital events or periodic censuses--are far from adequate. Brass Coale and their coworkers have developed a powerful set of techniques based on simple survey or census questions to replace the classical methods. This paper adds to the literature of numerical studies and regression analyses by providing and employing an analytic technique for studying the sensitivities of the estimates to the assumptions that underlie them. This new technique provides algebraic expressions which are both more general and easier to interpret than computer results. The authors illustrate the use of the analytical method in the simplest and most widely used technique--Brass childhood survivorship method. The notation and assumption of Brass childhood mortality method is set forth a general theory of errors for this estimator is developed and 4 specific analyses of practical interest are provided. As a general conclusion the technique is relatively robust with regard to poor choice of the mortality probability schedule as long as the estimation of age M is not very different from the average age A of the target children--children of mothers aged x. Errors caused by poor choice of density are more difficult to guard against; additional information that improves the accuracy of density is the only safe recourse. Good estimates of the infant mortality rate are difficult to obtain from Brass method. If the authors are willing to model exactly how certain specific demographic assumptions are violated they can derive algebraic expressions for the bias in the estimate. The theory rests on an application of differential calculus. Although not exact the results in this paper should be regarded as indicative of the type of bias introduced its magnitude and the factors on which it depends.

Changes in smoking behavior in various population subgroups can be estimated by using a technique that also has applications in other demographic work. The technique is especially valuable where the available aggregate data for such things as age groups or survey intervals are irregular. When tested on smoking statistics from the New Zealand census which is conducted every 5 years and aggregates age group data in 5-year increments the method achieved statistically comparable results using irregular data to estimate the transition rates into and out of the population of smokers in the U.S. The method estimates net transition rates 1st by considering data for regular age groups and then expanding the formula to include irregular age groups. It also considers the special treatment necessary for the final open interval. Underlying the method is the assumption that age-specific growth rates of population subgroups are approximately constant within the age intervals specified by the data population. The technique produces better estimates the smaller the age intervals are and weak results for the open-ended age group. Changes in the proportions of the population married and single employed and unemployed or healthy and sick also may be estimated by the method. The technique can be used to study more than 2 population groups such as the proportion of light medium and heavy smokers.

Power transformations can often simplify the task of describing behavior in data that consist of positive measurements or counts. Tukey's diagnostic techniques based on two-dimensional plots are useful in searching for a suitable transformation in two types of data structures: multiple batches at different levels, and two-way tables. To these, we add plots for finding transformations in two other structures: a single batch, and y versus x. The basis for plots that indicate transformations for symmetrizing and for straightening is explored using second-order series approximations. For all four techniques, when the plot is roughly linear with slope 1 — p, the power of a transformation indicated by the plot is p. Each plot indicates whether any power transformation can be effective in achieving a desired objective.

Experimental social psychology has dealt primarily with situations that are not true social interactions; in a typical study, a subject responds to a fixed, artificial social stimulus such as a photograph, written description, or performance by a confederate. Although these artificial social stimuli provide experimental control over independent variables and can be analyzed using the types of statistical models originally developed for nonsocial experimental research, they provide little or no information about the interactive aspects of social behavior—the reciprocity or mutual contingency of the behavior of interaction partners. This paper describes a nonexperimenta l design specifically tailored to social interaction data that provides more information about individual differences and social influence in social interactions: a round robin design in which each person interacts with every other person. After a brief review of available models, a new and more general model for the analysis of social interaction data is presented, with an empirical demonstration using vocal activity data.

Population projections are key elements of many planning and policy studies but are inherently inaccurate. This study of past population projection errors provides a means for constructing confidence intervals for future projections. We first define a statistic to measure projection errors independently of the size of the population and the length of the projection period. A sample of U.S. Census Bureau and United Nations projections indicates that the distributions of components of the error statistic are relatively stable. We then use this information to construct confidence intervals for the total population of the United States through the year 2000. We find that for projections of total population size, simple projection techniques are more accurate than more complex techniques.

With the history of the U.S. federal budget for fiscal year 1986 as a vehicle, the usual processes in the executive branch and the Congress that establish health research priorities and the unusual developments that have shaped priorities for AIDS are described. In the 3 years between the initial formulation of the AIDS budget and its execution, there were numerous revisions and evidence of poor communication between scientists and policy makers. On the basis of this analysis, two recommendations are made: the director of the National Institutes of Health and the heads of other U.S. Public Health Service agencies should have discretionary funds to use for AIDS activities; and better channels of communication between the Congress, the Public Health Service, and outside biomedical researchers should be established for consultation on priorities for AIDS research.

The National Institutes of Health (NIH) has earned a reputation for excellence in the support and conduct of research to improve the health of the American people. It has maintained its leadership position in the international scientific community in the face of great changes in its political and social environment. Paradoxically, pressures for changes in the mission and organizational structure of the NIH continue to arise. In the past five years there have been proposals to establish at least 11 new institutes at NIH and to transfer four existing agencies into it. Last October Congress passed but President Reagan vetoed . . .

The growth of university-industry research relationships in biotechnology has raised questions concerning their effects, both positive and negative, on universities. A survey of over 1200 faculty members at 40 major universities in the United States reveals that biotechnology researchers with industrial support publish at higher rates, patent more frequently, participate in more administrative and professional activities and earn more than colleagues without such support. At the same time, faculty with industry funds are much more likely than other biotechnology faculty to report that their research has resulted in trade secrets and that commercial considerations have influenced their choice of research projects. Although the data do not establish a causal connection between industrial support and these faculty behaviors, our findings strongly suggest that university-industry research relationships have both benefits and risks for academic institutions. The challenge for universities is to find ways to manage these relationships that will preserve the benefits while minimizing the risks.An analysis is provided of a survey of over 1,200 faculty members at 40 major U.S. universities concerning their research activities and funding by industrial sources. The survey findings suggest that university-industry biotechnology research relationships have both benefits and risks for the university. Faculty members receiving industry support tend to be more productive. They publish, patent, and earn more. They participate in more administrative and professional activities, while teaching as much as other faculty members. However, their research also leads to more unpublished trade secrets, and commercial considerations may influence their choice of projects. The authors recommend public as well as commercial funding of research, protection of the right to publish research results, and university-industry agreements that do not unduly restrict faculty behavior.