Prevalence of suicidal ideation in German psychotherapy outpatients: A large multicenter assessment.

BACKGROUND: Suicidal ideation is a major concern in clinical practice. Yet, little is known about prevalence rates of suicidal ideation in patients undergoing outpatient psychotherapeutic treatment. Therefore, the aim of the current study is to assess the prevalence of suicidal ideation in a large sample of psychotherapy outpatients in Germany. The data analyzed in this study is taken from the KODAP-project on the coordination of data collection and analysis at German university-based research and training outpatient clinics for psychotherapy. METHODS: A total of N = 10,357 adult outpatients (64.4 % female; age: M(SD) = 35.94 (13.54), range: 18-92 years of age) starting cognitive-behavioral therapy at one of 27 outpatient clinics in Germany were included in the current study. Prevalence of suicidal ideation was assessed with the Suicide Item (Item 9) of the Beck-Depression Inventory II. RESULTS: Suicidal ideation was reported by 36.7 % (n = 3795) of the participants. Borderline Personality Disorder, Posttraumatic Stress Disorder, and recurrent Major Depression were the diagnoses most strongly associated with the presence and severity of suicidal ideation. LIMITATION: Suicide ideation was assessed only with the respective item of the Beck Depression Inventory II. CONCLUSION: Suicidal ideation is very common among adult patients who start psychotherapy in Germany. A well-founded knowledge of risk assessment in suicidal patients and suicide-specific treatment options is therefore highly relevant.

The end of world population growth.

There has been enormous concern about the consequences of human population growth for the environment and for social and economic development. But this growth is likely to come to an end in the foreseeable future. Improving on earlier methods of probabilistic forecasting, here we show that there is around an 85 per cent chance that the world's population will stop growing before the end of the century. There is a 60 per cent probability that the world's population will not exceed 10 billion people before 2100, and around a 15 per cent probability that the world's population at the end of the century will be lower than it is today. For different regions, the date and size of the peak population will vary considerably.

Patient profiling: an application of random coefficient regression models to depicting the response of a patient to outpatient psychotherapy.

Adaptive treatment planning is a dynamic process that is dependent on valid, systematic assessments. The dosage and phase models provide theoretical bases for the development of such "patient-focused" information. Given an underlying mathematical regularity to the recovery process, growth modeling techniques can be used to determine an expected treatment response for every patient. By mapping the patient's actual status against such an expected change trajectory, it is possible to address the most clinically relevant question, "Is this treatment working?"

Dose-response relationships in chemical carcinogenesis reflect differences in individual susceptibility. Consequences for cancer risk assessment, extrapolation, and prevention.

The shape of the dose-cancer incidence curve observed in an animal bioassay for carcinogenicity of a chemical is the result of a superposition of various mechanisms contributing to the process of carcinogenesis. For genotoxic carcinogens, for instance, a sublinear (convex; up-bent) shape could be the result of a saturation of DNA repair or of a higher rate of cell turnover associated with high-dose cytotoxicity and regenerative hyperplasia. In human cancer epidemiology, the situation is more complex. The human population is very heterogeneous with respect to both genetic and life-style factors that modulate the process of tumor formation. Therefore, individuals are expected to show widely variable susceptibility to carcinogenic factors, and the dose-response curve is in fact a reflection of the tolerance distribution. Each modulating factor divides the population up into subpopulations of different susceptibility so that nonlinearities that could be present in a homogeneous population are flattened out. A linear extrapolation of a human cancer risk to low dose might therefore be appropriate under certain conditions even if the dose-response curve in animals has a strongly sigmoidal shape. For cancer prevention, the investigation of susceptibility factors is expected to be of great value. The elimination of concurrent risk factors in high-risk subpopulations or individuals might be more effective than a minor general reduction of a tolerable exposure level.

Endogenous growth of population and income depending on resource and knowledge.

PIP: This study focuses on the dynamic, endogenous, nonlinear interactions between the economy, population growth and the environment. Literature on endogenous growth theory was reviewed and the 3-sector demoeconomic model was provided as the analytical framework for the study of sustainable development through the integration of population growth, resource use and economic growth. The model is described in such a way that the labor force is considered as a free migrating variable among three different kinds of employment: the primary sector, which harvests a renewable resource, the secondary or industrial sector, and the tertiary sector, which is responsible for the accumulation of the stock that represents a public good for all three sectors. Presented in this paper is a nontechnical outline of the model that describes the economic, demographic, and environmental interactions considered. Also given are dynamics, market equilibrium and dynamic feedback rules. Furthermore, numerical analysis of the model quantifying the resulting time paths of the variables involved is included. The dynamics are simply the outcome of the nonlinear interactions of the demographic, economic and environmental modules. Numerical studies have also shown that the system variables move with different velocity. Technology and population can generally be regarded as slow moving variables by comparison with resources.^ieng

An expert-based framework for probabilistic national population projections: the example of Austria.

PIP: This study recommends a probabilistic scenario approach for population projections. The benefits are better information, ease of adoption, and expert opinion on the mean and range of uncertainty. The study answers whether it matters if high and low variants cover 85% or 95% of the range. An assumption of piece-wise linear random paths may underestimate the variance of the resulting population age distribution. A more realistic random path would have short-term fluctuations with some degree of autocorrelation. The expert-based probabilistic approach is applied to Austria. Official projections to 2050, account for 3 alternative migration assumptions and the usual fertility and life expectancy assumptions. Austria may have an absolute deficit of 60,000 persons after 2025. Population aging will increase from 19.7% to over 30%. The mean age of population will reach 50 years. The social implications of the alternative degrees of population aging are likely to have significant effects, such as on the pension system. The results of a test of the sensitivity of results for 85% and 95% confidence intervals and the impact on population size and old-age dependency outcomes reveal larger standard deviations and differences between fractiles with the 85% assumption of all cases lying between high and low values. Differences were larger between 85% and 90%, although not very significantly, than between 90% and 95%. When assuming short-term fluctuations, there was a greater range of uncertainty in the first 20 years than a standard linear interpolation, but long-term projections had lower standard deviations.^ieng

Molecular epidemiology: cancer risk assessment using biomarkers for detecting early health effects in individuals exposed to occupational and environmental carcinogens.

Detecting changes that precede the overt symptoms of cancer and identifying measurable indices of such changes in persons exposed to occupational and environmental carcinogens constitutes one of the primary objectives of molecular epidemiology research. Biomarkers represent a valuable research tool that makes it possible to attain that objective. Suitably selected biomarker sets may provide information on the extent of exposure to carcinogenic agents (internal dose, biologically effective dose), detect early changes caused by those agents in the exposed organism, and identify individuals with a particularly high risk of cancer development. The tremendous progress in research on the mechanisms of cancer initiation and promotion has enabled the assessment of cancer risk in healthy individuals by examining specific results from determinations of suitably selected biomarkers. The finding that gene defects (gene mutations and changes of their expression) constitute the background of carcinogenesis has resulted in molecular biology becoming focused on detecting defective genes or proteins synthesized under control of the defective genes.

Determination of tissue polypeptide antigens (TPA) and carcinoembryonic antigen (CEA) in serum: its value in the preliminary cancer risk assessment in asbestos exposed workers.

Seeking the changes at the cellular level or at the level of cellular metabolism products, present in the biological fluids, in order to detect early stages of the carcinogenic process is an essential step in preventing cancer development among asbestos exposed workers. Carcinogenic biomarkers such as tissue polypeptide antigens (TPA) and carcinoembryonic antigen (CEA) were found very useful in this attempt. The objective of this work was to identify individuals at critical cancer risk in the population of workers exposed to asbestos and to evaluate the value of TPA and CEA determinations for this particular purpose. The study was carried out in the group of workers exposed to asbestos (n = 274). Age, exposure duration, smoking habits and the kind of job performed, were considered in the analysis of the results. To sum up, it should be concluded that in 22 persons exposed to asbestos TPA values exceeded the cut off concentrations, established on the basis of the studies performed in the control group, and CEA value accounted for 10 ng/lm. Statistically significant differences in the percentage of TPA increased values between two groups under study were indicated. Such a relationship did not apply to CEA. In the exposed group, an evident effect of the age and exposure duration on the number of persons with TPA concentrations above the cut off, was also revealed. These changes show a growing tendency and statistical significance for TPA only. Smoking had a great impact on the occurrence of TPA increased concentrations. Three kinds of jobs were considered: operation of the production line, white collar workers and miscellaneous'. The significant differences in TPA concentrations between the operators and miscellaneous, and between white collar workers and miscellaneous were found. Therefore, it may be concluded that a similar percentage of TPA increased values was observed in the group of operators and white collar workers. The study allowed to identify, among those exposed to asbestos, 22 persons who should be covered with target medical care. It also indicated that TPA determination was more useful than that of CEA in this kind of investigations.

Spotlight: Mauritius.

PIP: Mauritius is an island nation of 780 sq. miles, with land area just 10 times the size of Washington, DC. Following malaria eradication in the late 1940s, Mauritius experienced one of the world's highest population growth rates. In 1957, the Mauritius Family Planning Association was founded and, in 1962, the Roman Catholic Church began promoting natural family planning. Between 1963 and 1972, the total fertility rate in the country fell from 6.2 children/woman to 3.2. The population's understanding that land space is limited appears to have contributed to the rapid fertility decline. Economic growth followed the rapid fertility decline, with the well-educated female population providing the labor for the country's textile factories and per capita income rising to $3380. Mauritius' population as of mid-1997 was 1.1 million, or 1450 people per square mile. Birth and death rates are 18 and 7 per 1000 population, respectively, there are 19.7 infant deaths per 1000 live births, the population is growing through natural increase at the annual rate of 1.2%, the total fertility rate is 2.1 births/woman, and the male and female life expectancies are 66 and 74 years, respectively. About half of all married women use modern contraception.^ieng

Biomarkers used for the assessment of health hazards in populations living in the vicinity of communal and industrial waste dump sites.

The measure of individual hazard from exposure to environmental toxicants are the biomarkers which are indices of abnormalities within different biological systems that may be induced by hazardous agents of various chemical or biological nature. The biomarkers make it possible to "monitor" the processes within the organism from the moment of toxic agent penetration to the development of clinical symptoms. Biomarkers offer the possibility of early detection of phenomena which tend to be arranged in the sequence of pathogenic changes, usually not detectable by the conventional methods. Depending on the type of processes which accompany the effect of a specified harmful environmental agent on the human organism it may be determined with the aid of the biomarkers, which are then classified as exposure, health effect, and individual susceptibility. By integrating such concepts as exposure, health effect, and individual susceptibility, enhanced analysis of the problem of health risk in people exposed to environmental toxic agents has become possible.

The future of world population.

PIP: Analysis of future population trends reveals a regional pattern of continued growth, dependent upon basic assumptions about demographic factors and the priority given to human rights, socioeconomic development, and global interdependence. Developing countries will account for 85-87% of world population growth, and the most rapid increase will occur in Africa. The optimum size of population remains debatable. Ecologist argue for a reduction to 1-2 billion people in order to be in balance with nature and maintain a high quality of life. A rapid, but plausible, fertility decline would result in a population of 10 billion by 2070. The lowest feasible UN projection is 8 billion. A 1-2 billion world population would not be feasible without drastic mortality increases and fertility declines. Population control is a highly charged and complex issue; feminists are not about to place responsibility for environmental degradation on women's excess fertility. The spirit of the UN Universal Declaration of Human Rights is that women have the right to determine family size with personal integrity and freedom rather than suffer coercion for the rights of society. Family planning is a necessary ingredient for achieving the goal of desired family size. The quality of life may be undermined by upholding human rights, without recognition of the context of socioeconomic development and global interdependencies. Global economic conditions, political crises, and environmental degradation can undermine even the best national development efforts. The most difficult task ahead is addressing priorities and forming a consensus. Human rights, socioeconomic conditions, and global interdependencies must be satisfied in a mutually beneficial way. When national and global goals conflict, a compromise must be reached. There are many unknowns. The challenge is to "identify a set of policies that will stabilize world climatic conditions, promote economic development, enhance the quality of life, and respect human rights." Investment in human capital, such as education and health, will help women to avoid unwanted pregnancies. Improving the status of women is key to socioeconomic development, human rights, and global interdependencies.^ieng

Mauritius finds the magic mix.

PIP: The experience in Mauritius highlights the central importance of investments in human resources, particularly female education, to sustainable social and economic development. Fertility on this island declined from 6.2 to 3.2 children per woman between 1963-72, and this unprecedented fertility decline was followed, in the 1980s, by dramatic economic growth. This scenario challenges the traditional belief that economic growth is an essential precondition for fertility decline. Increasing age at marriage and decreased marital fertility resulting from national family planning programs contributed equally to the fertility decline in the 1960s. Female secondary education increased simultaneously with reductions in fertility--a trend that resulted in increased age at marriage, a reduction in desired family size, increased receptivity to contraceptive use, and higher labor forced participation rates. Increased participation of women in the labor force in turn, was key to the economic growth of the export-oriented textiles industry. Future economic development depends on the education of a highly skilled labor force capable of addressing the need for structural changes in the economy and environmental protection measures.^ieng

Comparison of calculated and measured heterogeneity correction factors for 125I, 137Cs, and 192Ir brachytherapy sources near localized heterogeneities.

The influence of tissue and applicator heterogeneities on brachytherapy dose distributions is not well understood, despite widespread use of shielded applicators in intracavitary therapy. Heterogeneity correction factors (HCF) have been measured using a silicon diode detector arising from bounded heterogeneities consisting of lead, steel, titanium, silver, aluminum, and air cylinders near brachytherapy sources of 125I, 137Cs, and 192Ir. In addition, transverse-axis dose distributions for the three sources in homogeneous water were measured for distances of 0.2 to 16.0 cm. For each point of measurement, relative diode readings were simulated by a Monte Carlo photon transport code utilizing accurate models of the source internal structure, the experimental measure geometry and the source-strength calibration geometry. Comparison of measured and calculated HCF's reveals excellent agreement (1%-3% average) over a wide range of materials, diameters, and thicknesses. In addition, Monte Carlo simulation not only accurately reproduced the relative transverse-axis dose distributions in homogeneous medium, but was able to predict the variation of diode response with photon energy with an accuracy of 3% over the range of 30-662 keV. Our measurements demonstrate that HCF's vary by as much as 60%-100% with distance and heterogeneity diameter for a fixed thickness. Finally, silicon diode measurements of HCF (denied as reading with heterogeneity/reading in homogeneous medium) is shown to lead to errors of 5%-30% for 137Cs and 192Ir sources in the presence of high-atomic number shielding materials. This paper concludes, that Monte Carlo simulation is a powerful, convenient and accurate tool for investigating the long-neglected area of brachytherapy heterogeneity corrections.

Biological markers of early health effects in the assessment of the risk of cancer in people exposed to environmental carcinogens.

Biomarkers of early health effects represent the intermediate stages of the carcinogenesis process, between the initiation and conversion stage and the clinically overt neoplastic disease. The cellular processes indicated by those markers correspond, therefore, to the promotion process. Detection of those cellular processes is extremely important, as the promotion process lasts for many years and bears some signs of being reversible. The promotion process, consisting of a range of consecutive cellular changes involves, among others, activation of proto-oncogens and their transformation into oncogens, and inactivation of the suppressor genes. Therefore, the possibility of observing the trends of those changes by monitoring protein products of the oncogens and suppressor genes in the easily available material (blood, urine) is very useful. Inhibition of intercellular communication seems to play an extremely important role in the complex mechanism of transformation of a normal cell into a neoplastic one. During the carcinogenic process promotion stage, the inhibition is associated with the proteins which form the intercellular junctions and participate in cellular adhesion. That group of proteins includes carcinoembryonal antigen (CEA) and tissue polypeptide antigen (TPA), the tumour antigens which have been known for years. The possible relationship between increased TPA and CEA concentrations is supported not only by the data from the oncology but also by the data from the studies on populations exposed to agents known to increase the risk of neoplastic disease.

The real role of risk assessment in cancer risk management.

Regulatory actions taken to reduce the risk of harmful effects of exposure to chemicals often are not commensurate with the toxicological risk assessment. A number of factors relating to psychology, sociology, economics and politics rather than science and medicine affect the final decision. Werner Lutz and colleagues illustrate the situation using the leukemia-inducing chemical benzene as an example.

Population and sustainable development.

The author previews an interdisciplinary research project on Mauritius on population and sustainable development. The project will focus on the interrelationships among population, development, and the environment. "The expected result of the project will be a computerized information system based on a dynamic simulation model that will allow the user to run alternative scenarios, test various policy options, and show possible paths to specified goals."

The carcinogenic potential of ethyl carbamate (urethane): risk assessment at human dietary exposure levels.

Ethyl carbamate is found in fermented foods: bread contains 3-15 ng/g, stone-fruit brandies 200-20,000 ng/g, and about one-third of table-wine samples analysed contained more than 10 ng/g. In animals, ethyl carbamate is degraded to CO2, H2O and NH3, with intermediate formation of ethanol. This degradation has been shown to be inhibited (postponed) in the mouse by ethanol concentrations in the blood of about 0.15% and higher. A quantitatively minor pathway involves a two-step oxidation of the ethyl group to vinyl carbamate and epoxyethyl carbamate, the postulated electrophilic moiety that reacts with DNA. This reaction is probably the mode of the mutagenic action observed in many cellular and animal systems. The fact that only vinyl carbamate, but not ethyl carbamate, is mutagenic in a standard Ames test is probably because there is insufficient production of the intermediate oxidation product in the standard test. Consistent with this metabolism is the carcinogenic activity of ethyl carbamate in various animal species and in different organs; this activity can be seen even after a single high dose in early life. Quantitative analysis of the total tumour incidences after chronic exposure of rats and mice to 0.1-12.5 mg ethyl carbamate/kg body weight/day in the drinking-water showed a dose-related increase. The main target organs were the mammary gland (female rats and mice having similar susceptibilities) and the lung (mice only). On the basis of sex- and organ-specific tumour data and with a linear extrapolation to a negligible increase of the lifetime tumour incidence by 0.0001% (one additional tumour in one million individuals exposed for life), a "virtually safe dose" of 20 to 80 ng/kg body weight/day was estimated. The daily burden reached under normal dietary habits without alcoholic beverages is in the range of about 20 ng/kg body weight/day. Regular table-wine consumption would increase the risk by a factor of up to five. Regular drinking of 20 to 40 ml stone-fruit brandy per day could raise the calculated lifetime tumour risk to near 0.01%.

Randomisation by cluster and the problem of social class bias.

For randomised population trials the unit of randomisation is normally the individual person. In some situations, however, investigators take other groups as basic unit and one such design is cluster randomisation. Considerable attention has been given to this design recently in statistical and epidemiological literature. The Edinburgh randomised trial of breast cancer screening is an example which takes general practices as clusters of patients. The experience of this trial is reported here. Mortality from all causes, cardiovascular disease and lung cancer over the first 5 year period of follow up are examined. We found that spurious mortality differences were present in the analyses, which do not allow for socio-economic status. From examination of methods of adjusting for this, we conclude that allowance can be made at the analysis stage, and it is intended that this approach will be adopted when breast cancer mortality is analysed in the Edinburgh trial. Nevertheless, we recommend that for future studies with outcome related to socio-economic status, randomisations which use this design be stratified by socio-economic criteria where this is feasible.