Showing papers on "Population published in 1995"

Posttraumatic stress disorder in the National Comorbidity Survey.

Abstract: Background: Data were obtained on the general population epidemiology of DSM-III-R posttraumatic stress disorder (PTSD), including information on estimated lifetime prevalence, the kinds of traumas most often associated with PTSD, sociodemographic correlates, the comorbidity of PTSD with other lifetime psychiatric disorders, and the duration of an index episode. Methods: Modified versions of the DSM-III-R PTSD module from the Diagnostic Interview Schedule and of the Composite International Diagnostic Interview were administered to a representative national sample of 5877 persons aged 15 to 54 years in the part II subsample of the National Comorbidity Survey. Results: The estimated lifetime prevalence of PTSD is 7.8%. Prevalence is elevated among women and the previously married. The traumas most commonly associated with PTSD are combat exposure and witnessing among men and rape and sexual molestation among women. Posttraumatic stress disorder is strongly comorbid with other lifetime DSM-III-R disorders. Survival analysis shows that more than one third of people with an index episode of PTSD fail to recover even after many years. Conclusions: Posttraumatic stress disorder is more prevalent than previously believed, and is often persistent. Progress in estimating age-at-onset distributions, cohort effects, and the conditional probabilities of PTSD from different types of trauma will require future epidemiologic studies to assess PTSD for all lifetime traumas rather than for only a small number of retrospectively reported "most serious" traumas. (Arch Gen Psychiatry. 1995;52:1048-1060)

A quantitative assessment of plasma homocysteine as a risk factor for vascular disease. Probable benefits of increasing folic acid intakes

Abstract: Objective. —To determine the risk of elevated total homocysteine (tHcy) levels for arteriosclerotic vascular disease, estimate the reduction of tHcy by folic acid, and calculate the potential reduction of coronary artery disease (CAD) mortality by increasing folic acid intake. Data Sources. —MEDLINE search for meta-analysis of 27 studies relating homocysteine to arteriosclerotic vascular disease and 11 studies of folic acid effects on tHcy levels. Study Selection and Data Extraction. —Studies dealing with CAD, cerebrovascular disease, and peripheral arterial vascular disease were selected. Three prospective and six population-based case-control studies were considered of high quality. Five cross-sectional and 13 other case-control studies were also included. Causality of tHcy's role in the pathogenesis of vascular disease was inferred because of consistency across studies by different investigators using different methods in different populations. Data Synthesis. —Elevations in tHcy were considered an independent graded risk factor for arteriosclerotic vascular diseases. The odds ratio (OR) for CAD of a 5-μmol/L tHcy increment is 1.6(95% confidence interval [Cl], 1.4 to 1.7) for men and 1.8 (95% Cl, 1.3 to 1.9) for women. A total of 10% of the population's CAD risk appears attributable to tHcy. The OR for cerebrovascular disease (5-μmol/L tHcy increment) is 1.5 (95% Cl, 1.3 to 1.9). Peripheral arterial disease also showed a strong association. Increased folic acid intake (approximately 200 μg/d) reduces tHcy levels by approximately 4 μmol/L. Assuming that lower tHcy levels decrease CAD mortality, we calculated the effect of (1) increased dietary folate, (2) supplementation by tablets, and (3) grain fortification. Under different assumptions, 13 500 to 50 000 CAD deaths annually could be avoided; fortification of food had the largest impact. Conclusions. —A 5-μmol/L tHcy increment elevates CAD risk by as much as cholesterol increases of 0.5 mmol/L (20 mg/dL). Higher folic acid intake by reducing tHcy levels promises to prevent arteriosclerotic vascular disease. Clinical trials are urgently needed. Concerns about masking cobalamin deficiency by folic acid could be lessened by adding 1 mg of cobalamin to folic acid supplements. ( JAMA . 1995;274:1049-1057)

A measure of population subdivision based on microsatellite allele frequencies.

Abstract: A new measure of the extent of population subdivision as inferred from allele frequencies at microsatellite loci is proposed and tested with computer simulations. This measure, called R(ST), is analogous to Wright's F(ST) in representing the proportion of variation between populations. It differs in taking explicit account of the mutation process at microsatellite loci, for which a generalized stepwise mutation model appears appropriate. Simulations of subdivided populations were carried out to test the performance of R(ST) and F(ST). It was found that, under the generalized stepwise mutation model, R(ST) provides relatively unbiased estimates of migration rates and times of population divergence while F(ST) tends to show too much population similarity, particularly when migration rates are low or divergence times are long [corrected].

Robust text-independent speaker identification using Gaussian mixture speaker models

Abstract: This paper introduces and motivates the use of Gaussian mixture models (GMM) for robust text-independent speaker identification. The individual Gaussian components of a GMM are shown to represent some general speaker-dependent spectral shapes that are effective for modeling speaker identity. The focus of this work is on applications which require high identification rates using short utterance from unconstrained conversational speech and robustness to degradations produced by transmission over a telephone channel. A complete experimental evaluation of the Gaussian mixture speaker model is conducted on a 49 speaker, conversational telephone speech database. The experiments examine algorithmic issues (initialization, variance limiting, model order selection), spectral variability robustness techniques, large population performance, and comparisons to other speaker modeling techniques (uni-modal Gaussian, VQ codebook, tied Gaussian mixture, and radial basis functions). The Gaussian mixture speaker model attains 96.8% identification accuracy using 5 second clean speech utterances and 80.8% accuracy using 15 second telephone speech utterances with a 49 speaker population and is shown to outperform the other speaker modeling techniques on an identical 16 speaker telephone speech task. >

Prevalence of Hypertension in the US Adult Population: Results From the Third National Health and Nutrition Examination Survey, 1988-1991

Abstract: The purpose of this study was to estimate the current prevalence and distribution of hypertension and to determine the status of hypertension awareness, treatment, and control in the US adult population. The study used a cross-sectional survey of the civilian, noninstitutionalized population of the United States, including an in-home interview and a clinic examination, each of which included measurement of blood pressure. Data for 9901 participants 18 years of age and older from phase 1 of the third National Health and Nutrition Examination Survey, collected from 1988 through 1991, were used. Twenty-four percent of the US adult population representing 43 186 000 persons had hypertension. The age-adjusted prevalence in the non-Hispanic black, non-Hispanic white, and Mexican American populations was 32.4%, 23.3%, and 22.6%, respectively. Overall, two thirds of the population with hypertension were aware of their diagnosis (69%), and a majority were taking prescribed medication (53%). Only one third of Mexican Americans with hypertension were being treated (35%), and only 14% achieved control in contrast to 25% and 24% of the non-Hispanic black and non-Hispanic white populations with hypertension, respectively. Almost 13 million adults classified as being normotensive reported being told on one or more occasions that they had hypertension; 51% of this group reported current adherence to lifestyle changes to control their hypertension. Hypertension continues to be a common finding in the general population. Awareness, treatment, and control of hypertension have improved substantially since the 1976-1980 National Health and Nutrition Examination Survey but continue to be suboptimal, especially in Mexican Americans. Consideration should be given to revision of the criteria for classification of hypertension to reflect the widespread use of lifestyle modification for treatment of hypertension.

The prevalence and characteristics of fibromyalgia in the general population

Abstract: Objective. To determine the prevalence and characteristics of fibromyalgia in the general population. Methods. A random sample of 3,006 persons in Wichita, KS, were characterized according to the presence of no pain, non-widespread pain, and widespread pain. A subsample of 391 persons, including 193 with widespread pain, were examined and interviewed in detail. Results. The prevalence of fibromyalgia was 2.0% (95% confidence interval [95% CI] 1.4, 2.7) for both sexes, 3.4% (95% CI 2.3, 4.6) for women, and 0.5% (95% CI 0.0, 1.0) for men. The prevalence of the syndrome increased with age, with highest values attained between 60 and 79 years (>7.0% in women). Demographic, psychological, dolorimetry, and symptom factors were associated with fibromyalgia. Conclusion. Fibromyalgia is common in the population, and occurs often in older persons. Characteristic features of fibromyalgia–pain threshold and symptoms–are similar in community and clinic populations, but overall severity, pain, and functional disability are more severe in the clinic population.

Endarterectomy for asymptomatic carotid artery stenosis

Abstract: Reasonable doubt justifies randomisation European and North American clinicians have always differed in their management of carotid artery disease.1 Carotid endarterectomy is one of the commonest vascular procedures in North America, with over 360 operations per million population being performed each year.1 Meanwhile, despite the fact that the first carotid reconstruction was performed in Britain,1 selection for the procedure in Europe has been sporadic. British data for 1993-4 confirm that fewer than 40 carotid endarterectomies are performed per million population per year (personal communications from Department of Health, England; NHS Information and Statistics Division, Scotland; and Department of Health and Social Services, Northern Ireland, 1995). Two major multicentre trials, the North American symptomatic carotid endarterectomy trial and the European carotid surgery trial, both published in 1991, have helped to define the role of carotid endarterectomy in patients with symptoms, such as transient ischaemic attacks and non-disabling strokes.2 3 In symptomatic patients with an internal carotid artery stenosis of greater than 70%, endarterectomy produced a 75% reduction in rates of stroke over two to three years when compared with best medical treatment. These trials meant that carotid endarterectomy became a member of that small group of preventive surgical procedures that have withstood the test of a randomised controlled trial. Neurologists' lack of confidence in the outcome of carotid endarterectomy has contributed to low rates of referral in Europe.1 The benefit to patients with symptoms is acknowledged, but the impact of the operation on preventing stroke in the population has been challenged, as highlighted recently in the BMJ.4 Health service statistics suggest that the provision of endarterectomy for symptomatic patients is not uniform across the country. Given that Britain cannot optimally provide for patients …

The incidence of thyroid disorders in the community: a twenty-year follow-up of the Whickham Survey

Abstract: Summary BACKGROUND AND OBJECTIVE The original Whlckham Survey documented the prevalence of thyroid disorders in a randomly selected sample of 2779 adults which matched the population of Great Britain in age, sex and social class. The aim of the twenty-year follow-up survey was to determine the Incidence and natural history of thyroid disease in this cohort. DESIGN, PATIENTS AND MEASUREMENTS Subjects were traced at follow-up via the Electoral Register, General Practice registers, Gateshead Family Health Services Authority register and Office of Population Censuses and Surveys. Eight hundred and twenty-five subjects (30% of the sample) had died and, In addition to death certificates, two-thirds had Information from either hospital/General Practitioner notes or post-mortem reports to document morbidity prior to death. Of the 1877 known survivors, 96% participated in the follow-up study and 91 % were tested for clinical, biochemical and Immunological evidence of thyroid dysfunction. RESULTS Outcomes in terms of morbidity and mortality were determined for over 97% of the original sample. The mean Incidence (with 95% confidence Intervals) of spontaneous hypothyroidism in women was 3.5/1000 survivors/year (2.8-4.5) rising to 4.1/1000 survivors/year (3.3-5.0) for all causes of hypothyroidism and in men was 0.6/1000 survivors/year (0.3-1.2). The mean incidence of hyperthyroidism In women was 0.8/1000 survivors/year (0.5.1.4) and was negligible in men. Similar incidence rates were calculated for the deceased subjects. An estimate of the probability of the development of hypothyroidism and hyperthyroidism at a particular time, i.e. the hazard rate, showed an Increase with age In hypothyroidism but no age relation in hyperthyroidism. The frequency of goitre decreased with age with 10% of women and 2% of men having a goitre at follow-up, as compared to 23% and 5% in the same subjects respectively at the first survey. The presence of a goitre at either survey was not associated with any clinical or biochemical evidence of thyroid dysfunction. In women, an association was found between the development of a goitre and thyroid-antibody status at follow-up, but not initially. The risk of having developed hypothyroidism at follow-up was examined with respect to risk factors Identified at first survey. The odds ratios (with 95% confidence Intervals) of developing hypothyroidism with (a) raised serum TSH alone were 8 (3-20) for women and 44 (19-104) for men; (b) positive anti-thyroid antibodies alone were 8 (5-15) for women and 25 (10-63) for men; (c) both raised serum TSH and positive anti-thyroid antibodies were 38 (22-65) for women and 173 (81-370) for men. A loglt model Indicated that Increasing values of serum TSH above 2mU/l at first survey Increased the probability of developing hypothyroidism which was further Increased in the presence of anti-thyroid antibodies. Neither a positive family history of any form of thyroid disease nor parity of women at first survey was associated with Increased risk of developing hypothyroidism. Fasting cholesterol and triglyceride levels at first survey when corrected for age showed no association with the development of hypothyroidism In women. CONCLUSIONS This historical cohort study has provided Incidence data for thyroid disease over a twenty-year period for a representative cross-sectional sample of the population, and has allowed the determination of the importance of prognostic risk factors for thyroid disease Identified twenty years earlier.

An overview of evolutionary algorithms in multiobjective optimization

Abstract: The application of evolutionary algorithms (EAs) in multiobjective optimization is currently receiving growing interest from researchers with various backgrounds. Most research in this area has understandably concentrated on the selection stage of EAs, due to the need to integrate vectorial performance measures with the inherently scalar way in which EAs reward individual performance, that is, number of offspring. In this review, current multiobjective evolutionary approaches are discussed, ranging from the conventional analytical aggregation of the different objectives into a single function to a number of population-based approaches and the more recent ranking schemes based on the definition of Pareto optimality. The sensitivity of different methods to objective scaling and/or possible concavities in the trade-off surface is considered, and related to the (static) fitness landscapes such methods induce on the search space. From the discussion, directions for future research in multiobjective fitness assignment and search strategies are identified, including the incorporation of decision making in the selection procedure, fitness sharing, and adaptive representations.

Prevalence, Age Distribution, and Gender of Patients With Atrial Fibrillation: Analysis and Implications

Abstract: The prevalence of atrial fibrillation (AF) is related to age. Anticoagulation is highly effective in preventing stroke in patients with AF, but the risk of hemorrhage may be increased in older patients. We reviewed the available epidemiologic data to define the age and sex distribution of people with AF. From four large recent population-based surveys, we estimated the overall age- and gender-specific prevalence of AF. These estimates were applied to the recent US census data to calculate the number of men and women with AF in each age group. There are an estimated 2.2 million people in the United States with AF, with a median age of about 75 years. The prevalence of AF is 2.3% in people older than 40 years and 5.9% in those older than 65 years. Approximately 70% of individuals with AF are between 65 and 85 years of age. The absolute number of men and women with AF is about equal. After age 75 years, about 60% of the people with AF are women. In contrast to people with AF in the general population, patients with AF in recent anticoagulation trials had a mean age of 69 years, and only 20% were older than 75 years. The risks and benefits of antithrombotic therapy in older individuals are important considerations in stroke prevention in AF. (Arch Intern Med. 1995;155:469-473)

The Natural History of the Systemic Inflammatory Response Syndrome (SIRS): A Prospective Study

Abstract: Objective. —Define the epidemiology of the four recently classified syndromes describing the biologic response to infection: systemic inflammatory response syndrome (SIRS), sepsis, severe sepsis, and septic shock. Design. —Prospective cohort study with a follow-up of 28 days or until discharge if earlier. Setting. —Three intensive care units and three general wards in a tertiary health care institution. Methods. —Patients were included if they met at least two of the criteria for SIRS: fever or hypothermia, tachycardia, tachypnea, or abnormal white blood cell count. Main Outcomes Measures. —Development of any stage of the biologic response to infection: sepsis, severe sepsis, septic shock, end-organ dysfunction, and death. Results. —During the study period 3708 patients were admitted to the survey units, and 2527 (68%) met the criteria for SIRS. The incidence density rates for SIRS in the surgical, medical, and cardiovascular intensive care units were 857,804, and 542 episodes per 1000 patient-days, respectively, and 671,495, and 320 per 1000 patient-days for the medical, cardiothoracic, and general surgery wards, respectively. Among patients with SIRS, 649 (26%) developed sepsis, 467 (18%) developed severe sepsis, and 110 (4%) developed septic shock. The median interval from SIRS to sepsis was inversely correlated with the number of SIRS criteria (two, three, or all four) that the patients met. As the population of patients progressed from SIRS to septic shock, increasing proportions had adult respiratory distress syndrome, disseminated intravascular coagulation, acute renal failure, and shock. Positive blood cultures were found in 17% of patients with sepsis, in 25% with severe sepsis, and in 69% with septic shock. There were also stepwise increases in mortality rates in the hierarchy from SIRS, sepsis, severe sepsis, and septic shock: 7%, 16%, 20%, and 46%, respectively. Of interest, we also observed equal numbers of patients who appeared to have sepsis, severe sepsis, and septic shock but who had negative cultures. They had been prescribed empirical antibiotics for a median of 3 days. The cause of the systemic inflammatory response in these culture-negative populations is unknown, but they had similar morbidity and mortality rates as the respective culture-positive populations. Conclusions. —This prospective epidemiologic study of SIRS and related conditions provides, to our knowledge, the first evidence of a clinical progression from SIRS to sepsis to severe sepsis and septic shock. ( JAMA . 1995;273:117-123)

Maximum-likelihood estimation of molecular haplotype frequencies in a diploid population.

Abstract: Molecular techniques allow the survey of a large number of linked polymorphic loci in random samples from diploid populations. However, the gametic phase of haplotypes is usually unknown when diploid individuals are heterozygous at more than one locus. To overcome this difficulty, we implement an expectation-maximization (EM) algorithm leading to maximum-likelihood estimates of molecular haplotype frequencies under the assumption of Hardy-Weinberg proportions. The performance of the algorithm is evaluated for simulated data representing both DNA sequences and highly polymorphic loci with different levels of recombination. As expected, the EM algorithm is found to perform best for large samples, regardless of recombination rates among loci. To ensure finding the global maximum likelihood estimate, the EM algorithm should be started from several initial conditions. The present approach appears to be useful for the analysis of nuclear DNA sequences or highly variable loci. Although the algorithm, in principle, can accommodate an arbitrary number of loci, there are practical limitations because the computing time grows exponentially with the number of polymorphic loci. Although the algorithm, in principle, can accommodate an arbitrary number of loci, there are practical limitations because the computing time grows exponentially with the number of polymorphic loci.

HIV population dynamics in vivo: implications for genetic variation, pathogenesis, and therapy

Abstract: Several recent reports indicate that the long, clinically latent phase that characterizes human immunodeficiency virus (HIV) infection of humans is not a period of viral inactivity, but an active process in which cells are being infected and dying at a high rate and in large numbers. These results lead to a simple steady-state model in which infection, cell death, and cell replacement are in balance, and imply that the unique feature of HIV is the extraordinarily large number of replication cycles that occur during infection of a single individual. This turnover drives both the pathogenic process and (even more than mutation rate) the development of genetic variation. This variation includes the inevitable and, in principle, predictable accumulation of mutations such as those conferring resistance to antiviral drugs whose presence before therapy must be considered in the design of therapeutic strategies.

Body mass index reference curves for the UK, 1990.

Abstract: Reference curves for stature and weight in British children have been available for the past 30 years, and have recently been updated. However weight by itself is a poor indicator of fatness or obesity, and there has never been a corresponding set of reference curves to assess weight for height. Body mass index (BMI) or weight/height has been popular for assessing obesity in adults for many years, but its use in children has developed only recently. Here centile curves for BMI in British children are presented, from birth to 23 years, based on the same large representative sample as used to update the stature and weight references. The charts were derived using Cole's LMS method, which adjusts the BMI distribution for skewness and allows BMI in individual subjects to be expressed as an exact centile or SD score. Use of the charts in clinical practice is aided by the provision of nine centiles, where the two extremes identify the fattest and thinnest four per 1000 of the population.

Microsatellite analysis of population structure in Canadian polar bears.

Abstract: Attempts to study the genetic population structure of large mammals are often hampered by the low levels of genetic variation observed in these species. Polar bears have particularly low levels of genetic variation with the result that their genetic population structure has been intractable. We describe the use of eight hypervariable microsatellite loci to study the genetic relationships between four Canadian polar bear populations: the northern Beaufort Sea, southern Beaufort Sea, western Hudson Bay, and Davis Strait-Labrador Sea. These markers detected considerable genetic variation, with average heterozygosity near 60% within each population. Interpopulation differences in allele frequency distribution were significant between all pairs of populations, including two adjacent populations in the Beaufort Sea. Measures of genetic distance reflect the geographic distribution of populations, but also suggest patterns of gene flow which are not obvious from geography and may reflect movement patterns of these animals. Distribution of variation is sufficiently different between the Beaufort Sea populations and the two more eastern ones that the region of origin for a given sample can be predicted based on its expected genotype frequency using an assignment test. These data indicate that gene flow between local populations is restricted despite the long-distance seasonal movements undertaken by polar bears.

Changes in Physical Fitness and All-Cause Mortality: A Prospective Study of Healthy and Unhealthy Men

Abstract: Objective. —To evaluate the relationship between changes in physical fitness and risk of mortality in men. Design. —Prospective study, with two clinical examinations (mean interval between examinations, 4.9 years) to assess change or lack of change in physical fitness as associated with risk of mortality during follow-up after the subsequent examination (mean follow-up from subsequent examination, 5.1 years). Setting. —Preventive medicine clinic. Study Participants. —Participants were 9777 men given two preventive medical examinations, each of which included assessment of physical fitness by maximal exercise tests and evaluation of health status. Main Outcome Measures. —All-cause (n=223) and cardiovascular disease (n=87) mortality. Results. —The highest age-adjusted all-cause death rate was observed in men who were unfit at both examinations (122.0/10 000 man-years); the lowest death rate was in men who were physically fit at both examinations (39.6/10000 man-years). Men who improved from unfit to fit between the first and subsequent examinations had an age-adjusted death rate of 67.7/10 000 man-years. This is a reduction in mortality risk of 44% (95% confidence interval, 25% to 59%) relative to men who remained unfit at both examinations. Improvement in fitness was associated with lower death rates after adjusting for age, health status, and other risk factors of premature mortality. For each minute increase in maximal treadmill time between examinations, there was a corresponding 7.9% (P=.001) decrease in risk of mortality. Similar results were seen when the group was stratified by health status, and for cardiovascular disease mortality. Conclusions. —Men who maintained or improved adequate physical fitness were less likely to die from all causes and from cardiovascular disease during follow-up than persistently unfit men. Physicians should encourage unfit men to improve their fitness by starting a physical activity program. (JAMA. 1995;273:1093-1098)

Body weight and mortality among women

Abstract: Background The relation between body weight and overall mortality remains controversial despite considerable investigation. Methods We examined the association between body-mass index (defined as the weight in kilograms divided by the square of the height in meters) and both overall mortality and mortality from specific causes in a cohort of 115,195 U.S. women enrolled in the prospective Nurses' Health Study. These women were 30 to 55 years of age and free of known cardiovascular disease and cancer in 1976. During 16 years of follow-up, we documented 4726 deaths, of which 881 were from cardiovascular disease, 2586 from cancer, and 1259 from other causes. Results In analyses adjusted only for age, we observed a J-shaped relation between body-mass index and overall mortality. When women who had never smoked were examined separately, no increase in risk was observed among the leaner women, and a more direct relation between weight and mortality emerged (P for trend < 0.001). In multivariate analyses of women...

Prejudice as a response to perceived group threat: population composition and anti-immigrant and racial prejudice in Europe

Abstract: L'A. etudie la representation des prejudices. Il evalue la perception de la menace que les groupes subordonnes ferraient peser sur les groupes dominants. Il estime que les conditions economiques et l'importance des groupes subordonnes par rapport aux groupes dominants expliquent ce type de perception. Il note a partir de donneees europeennes des disparites entre les 12 sur ce plan precis. Cette perception de la menace « ethnique » expliquerait le sentiment de prejudice. L'A. invite aux vues de ses analyses a revoir celles du passe

Prevalence of Hypertrophic Cardiomyopathy in a General Population of Young Adults Echocardiographic Analysis of 4111 Subjects in the CARDIA Study

Abstract: Background Hypertrophic cardiomyopathy (HCM) is a genetically transmitted disease and an important cause of morbidity and sudden cardiac death in young people, including competitive athletes. At present, however, few data exist to estimate the prevalence of this disease in large populations. Methods and Results As part of the Coronary Artery Risk Development in (Young) Adults (CARDIA) Study, an epidemiological study of coronary risk factors, 4111 men and women 23 to 35 years of age selected from the general population of four urban centers had technically satisfactory echocardiographic studies during 1987 through 1988. Probable or definite echocardiographic evidence of HCM was present in 7 subjects (0.17%) on the basis of identification of a hypertrophied, nondilated left ventricle and maximal wall thickness ≥15 mm that were not associated with systemic hypertension. Prevalence in men and women was 0.26:0.09%; in blacks and whites, 0.24:0.10%. Ventricular septal thickness was 15 to 21 mm (mean, 17 mm) in ...

Global epidemiology of tuberculosis. Morbidity and mortality of a worldwide epidemic.

Abstract: This article describes the global epidemiology of tuberculosis and reviews recent estimates of tuberculosis incidence and mortality in the world. The highest prevalence of tuberculosis infection and estimated annual risk of tuberculosis infection are in sub-Saharan Africa and Southeast Asia. Overall, almost 3.8 million cases of tuberculosis were reported in the world in 1990, of which 49% were in Southeast Asia. From the period 1984 through 1986 to the period 1989 through 1991, notification rates increased in all World Health Organization regions, except the American and the European regions. In 1990, there were an estimated 7.5 million cases of tuberculosis and 2.5 million deaths worldwide. The human immunodeficiency virus epidemic is causing increases in the number of tuberculosis cases, particularly in Africa, although increases are also expected in Southeast Asia. In many industrialized countries, tuberculosis has recently failed to decline, and in eastern Europe and the former Soviet Union, cases and deaths are increasing. Drug resistance is a serious problem, especially in the United States. If worldwide control of tuberculosis does not improve, 90 million new cases and 30 million deaths are expected in the decade 1990 through 1999. (JAMA. 1995;273:220-226)

Infection with Helicobacter pylori Strains Possessing cagA Is Associated with an Increased Risk of Developing Adenocarcinoma of the Stomach

Abstract: To determine whether infection with a Helicobacter pylori strain possessing cagA is associated with an increased risk of development of adenocarcinoma of the stomach, we used a nested case-control study based on a cohort of 5443 Japanese-American men in Oahu, Hawaii, who had a physical examination and a phlebotomy during 1967 to 1970 We matched 103 H pylori -infected men who developed gastric cancer during a 21-year surveillence period with 103 H pylori -infected men who did not develop gastric cancer and tested stored serum specimens from patients and controls for the presence of serum IgG to the cagA product of H pylori using an ELISA The serum IgG assay using a recombinant CagA fragment had a sensitivity of 944% and a specificity of 925% when used in a clinically defined population; serological results were stable for more than 7 years For men with antibodies to CagA, the odds ratio of developing gastric cancer was 19 (95% confidence interval, 09–40); for intestinal type cancer of the distal stomach, the odds ratio was 23 (95% confidence interval, 10–52) Age cagA -positive H pylori strain in comparison with a cagA -negative strain somewhat increases the risk for development of gastric cancer, especially intestinal type affecting the distal stomach

Factors Predicting the Subjective Well-Being of Nations

Abstract: Subjective well-being (SWB) in 55 nations, reported in probability surveys and a large college student sample, was correlated with social, economic, and cultural characteristics of the nations. The SWB surveys, representing nations that include three fourths of the earth's population, showed strong convergence. Separate measures of the predictor variables also converged and formed scales with high reliability, with the exception of the comparison variables. High income, individualism, human rights, and societal equality correlated strongly with each other, and with SWB across surveys. Income correlated with SWB even after basic need fulfillment was controlled. Only individualism persistently correlated with SWB when other predictors were controlled. Cultural homogeneity, income growth, and income comparison showed either low or inconsistent relations with SWB.

The Healthy Eating Index: design and applications.

Abstract: Objective To develop an index of overall diet quality. Design The Healthy Eating Index (HEI) was developed based on a 10-component system of five food groups, four nutrients, and a measure of variety in food intake. Each of the 10 components has a score ranging from 0 to 10, so the total possible index score is 100. Methods/subjects Data from the 1989 and 1990 Continuing Survey of Food Intake by Individuals were used to analyze the HEI for a representative sample of the US population. Statistical analyses performed Frequencies, correlation coefficients, means. Results The mean HEI was 63.9; most people scored neither very high nor very low. No one component of the index dominated the HEI score. People were most likely to do poorly in the fruit, saturated fat, grains, vegetable, and total fat categories. The HEI correlated positively and significantly with most nutrients; as the total HEI increased, intake for a range of nutrients also increased. Discussion/conclusions The HEI is a useful index of overall diet quality of the consumer. The US Department of Agriculture will use the HEI to monitor changes in dietary intake over time and as the basis of nutrition promotion activities for the population. J Am Diet Assoc. 1995; 95:1103-1108.

Assessing psychopathic attributes in a noninstitutionalized population.

Abstract: The present study examined antisocial dispositions in 487 university students. Primary and secondary psychopathy scales were developed to assess a protopsychopathic interpersonal philosophy. An antisocial action scale also was developed for purposes of validation. The primary, secondary, and antisocial action scales were correlated with each other and with boredom susceptibility and disinhibition but not with experience seeking and thrill and adventure seeking. Secondary psychopathy was associated with trait anxiety. Multiple regression analysis revealed that the strongest predictors of antisocial action were disinhibition, primary psychopathy, secondary psychopathy, and sex, whereas thrill and adventure seeking was a negative predictor. This argues against a singular behavioral inhibition system mediating both antisocial and risk-taking behavior. These findings are also consistent with the view that psychopathy is a continuous dimension.

Biodiversity: Population Versus Ecosystem Stability

Abstract: The relationships between biodiversity and stability were determined for both population and ecosystem traits in a long-term study of 207 grassland plots. Results demonstrate that biodiversity stabilizes community and ecosystem processes, but not pop- ulation processes. Specifically, year-to-year variability in total aboveground plant com- munity biomass was significantly lower in plots with greater plant species richness both for the entire 11-yr period and for the nine non-drought years. The change in total plant community biomass from before the drought to the peak of the drought was also highly dependent on species richness. For all three measures of total community biomass stability, multiple regressions that controlled for covariates showed similar significant relationships between plant diversity and stability. In contrast, year-to-year variability in species abundances was not stabilized by plant species richness for either all years or non-drought years. This difference between species vs. community biomass likely results from interspecific competition. When climatic vari- ations harm some species, unharmed competitors increase. Such compensatory increases stabilize total community biomass, but cause species abundances to be more variable. These results support both the predictions of Robert May concerning the effects of diversity on population stability and the diversity-stability hypothesis as applied to community and ecosystem processes, thus helping to reconcile a long-standing dispute.

Youth Risk Behavior Surveillance-United States, 1993

Abstract: Priority health risk behaviors that contribute to the leading causes of mortality, morbidity, and social problems among youth and adults often are established during youth, extend into adulthood, and are interrelated. The Youth Risk Behavior Surveillance System (YRBSS) monitors six categories of priority health risk behaviors among youth and youth adults: behaviors that contribute to unintentional and intentional injuries, tobacco use, alcohol and other drug use, sexual behaviors, dietary behaviors, and physical activity. The YRBSS includes a national, school-based survey conducted by CDC and state and local school-based surveys conducted by state and local education agencies. This report summarizes results from the national survey, 24 state surveys, and nine local surveys conducted among high school students during February through May 1993. In the United States, 72% of all deaths among school-age youth and young adults are from four causes: motor vehicle crashes, other intentional injuries, homicide, and suicide. Results from the 1993 YRBSS suggest many high school students practice behaviors that may increase their likelihood of death from these four causes: 19.1% rarely or never use a safety belt, 35.3% had ridden during the 30 days preceding the survey with a driver who had been drinking alcohol, 22.1% had carried a weapon during the 30 days preceding the survey, 80.9% ever drank alcohol, 32.8% ever used marijuana, and 8.6% had attempted suicide during the 12 months preceding the survey. Substantial morbidity and social problems among adolescents also result from unintended pregnancies and sexually transmitted diseases including HIV infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Hypertension : pathophysiology, diagnosis, and management

Abstract: CONTENTS: BACKGROUND AND HISTORICAL ASPECTS: Hypertension: Definitions, Natural Histories, and Consequences Sir George Pickering Afterword to Chapter 1: Modern Definitions and Expressions of Hypertension Thomas G. Pickering The Goldblatt Experiment: A Conceptual Paradigm Peter J. Goldblatt The Vascular Fault in Hypertension: Byrom's Work Revisited John M. Ledingham. EPIDEMIOLOGICAL DIMENSIONS OF HYPERTENSION: Does Hypertension Predispose to Coronary Disease? Conflicting Epidemiological and Experimental Evidence Austin E. Doyle Genetic Epidemiology of Blood Pressure Ryk Ward Low Birth Weight as a Risk Factor for Juvenile and Adult Hypertension Glenn M. Chertow and Barry M. Brenner Hypertension, Other Risk Factors, and the Risk of Cardiovascular Disease William B. Kannel and Peter W. F. Wilson Human Population Biology and Blood Pressure: Evolutionary and Ecological Considerations and Interpretations of Population Studies Gary D. James and Paul Baker Impact of Systolic and Diastolic Blood Pressure on Cardiovascular Mortality James D. Neaton, Lewis Kuller, Jeremiah Stamler, and Deborah N. Wentworth Epidemiology and Treatment of Hypertension in Older Persons Adrian M. Ostfeld, Richard J. Havlik, and Jack Guralnik Hypertension in Women Ellen Cohen, Mary E. (Polly) Wheat, Deborah M. Swiderski, and Pamela Charney High Blood Pressure in Blacks: Salt, Slavery, Survival, Stress, and Racism Clarence E. Grim, James P. Henry, and Hector Myers Childhood Hypertension Alan R. Sinaiko Hypertension in the Elderly Richard L. Byyny Public Health Issues in Hypertension Control: What Has Been Learned from Clinical Trials Jeffrey A. Cutler, Bruce M. Psaty, Stephen MacMahon, and Curt D. Furberg. DIET AND HYPERTENSION: Blood Pressure and Sodium Intake Olaf F. Simpson Dietary Sodium Restriction in Hypertension John D. Swales Dietary K $PL, Na, and Cardiovascular Integrity in Experimental Models of Hypertension Louis Tobian Blood Pressure and K $PL Intake R. C. Morris, Jr., and Anthony Sebastian The Role of Dietary Protein in Hypertensive Disease: The Japanese Experience: Clinical Implications Walter M. Lovenberg and Yukio Yamori. CIRCULATORY AND TARGET ORGAN PATHOPHYSIOLOGY OF HYPERTENSIVE DISEASE: Hemodynamic Patterns of Untreated Hypertensive Disease Per Lund-Johansen and Per Omvik Evaluation of Arterial Waveforms in Hypertension and Normotension Michael F. O'Rourke and Raymond P. Kelly Blood Viscosity as a Factor in Human Hypertension Shu Chien and Ann Chabanal Vascular Compliance and Blood Volume in Essential Hypertension Michael E. Safar, G erard E. Plante, and G erard M. London Red Blood Cell Mass/Erythropoietin and Blood Pressure: Lessons from Patients with Renal Disease Joseph W. Eschbach and Robert C. Davidson Interactions Between the Sympathetic Nervous System and the Renin-Angiotensin System Guiseppe Mancia, Antonio Saino, and Guido Grassi Hypertensive Cardiac Hypertrophy: Pathophysiologic and Clinical Characteris

Overweight Prevalence and Trends for Children and Adolescents: The National Health and Nutrition Examination Surveys, 1963 to 1991

Abstract: Objective: To examine prevalence of overweight and trends in overweight for children and adolescents in the US population. Design: Nationally representative cross-sectional surveys with an in-person interview and a medical examination, including measurement of height and weight. Participants: Between 3000 and 14000 youths aged 6 through 17 years examined in each of five separate national surveys during 1963 to 1965, 1966 to 1970, 1971 to 1974, 1976 to 1980, and 1988 to 1991 (Cycles II and III of the National Health Examination Survey, and the first, second, and third National Health and Nutrition Examination Surveys, respectively). Main Outcome Measures: Prevalence of overweight based on body mass index and 85th or 95th percentile cutoff points from Cycles II and III of the National Health Examination Survey. Results: From 1988 to 1991, the prevalence of over-weight was 10.9% based on the 95th percentile and 22% based on the 85th percentile. Overweight prevalence increased during the period examined among all sex and age groups. The increase was greatest since 1976 to 1980, similar to findings previously reported for adults in the United States. Conclusions: Increasing overweight among youths implies a need to focus on primary prevention. Attempts to increase physical activity may provide a means to address this important public health problem. (Arch Pediatr Adolesc Med. 1995;149:1085-1091)