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PubMed2004

Predictive model of diagnosing probable cases of severe acute respiratory syndrome in febrile patients with exposure risk.

STUDY OBJECTIVE: Since the World Health Organization issued a global alert about severe acute respiratory syndrome (SARS) on March 12, 2003, the illness has become a major public health challenge worldwide. The objective of this study is to identify the clinical risk factors of SARS and to develop a scoring system for early diagnosis. METHODS: The detailed clinical data of all patients presenting to the emergency department (ED) with a temperature higher than 38.0 degrees C (100.3 degrees F), documented at home or at the ED, and risks of exposure to SARS within 14 days were assessed. The diagnosis of probable SARS was made according to the definition of the Centers for Disease Control and Prevention. Items with significant differences among symptoms, signs, and laboratory tests on presentation between SARS and non-SARS groups were determined and used to develop the scoring system. RESULTS: Seventy patients were enrolled and 8 were diagnosed as probably having SARS. None of the initially discharged patients or their relatives developed SARS. Compared with the non-SARS group, the SARS group was younger (33.9+/-15.9 years versus 44+/-9.8 years; P=.02), had a higher percentage of fever prolonged more than 5 days (87.5% versus 6.5%; P<.01), myalgia (75% versus 27.4%; P=.01), and diarrhea (50% versus 9.7%; P=.02); had less occurrence of cough before or during fever (0% versus 64.5%; P=.01); and had lower absolute lymphocyte (0.9+/-0.3x10(9)/L versus 1.5+/-1.1x10(9)/L; P<.01) and platelet counts (144.1+/-36.3x10(9)/L versus 211.6+/-78.8x10(9)/L; P=.02). A 4-item symptom score based on the presence of cough before or concomitant with fever, myalgia, diarrhea, and rhinorrhea or sore throat detects SARS with 100% sensitivity and 75.9% specificity; a 6-item clinical score based on lymphopenia (<1.0x10(9)/L), thrombocytopenia (<150x10(9)/L) and the 4 symptom items detects SARS with 100% sensitivity and 86.3% specificity. CONCLUSION: Certain symptoms and laboratory tests indicate higher risk of febrile probable SARS. In nonendemic areas, the febrile patients with recent contact with SARS or travel history to endemic areas could be screened for the probability of SARS by the use of clinical and symptom scores.

Adolescent↗
PubMed1999

A legislative view on science and predictive models.

Preparation of European environmental policy needs detailed and consistent assessments. All possible and available means have to be applied to get the optimal solution for current and upcoming problems in the environment. As there will be a recognition of the increasing importance of linkages between the various aspects in the environment, a sound and appropriate method for tackling the integration problem is needed. One of the main features of Integrated Environmental Assessment (IEA) deals with the linkage between societal activities and the relevant environmental issues. The European Environment Agency (EEA) uses a chain of linkages between the driving forces within society (D), the pressure on the environment (P), the state of the environment itself (S), the impact on people and nature (I) and the desirable response (R). This approach is called the DPSIR chain. For each environmental issue a chain, including the linkages, could be developed by combining available knowledge and data. In fact it is a complex multi-dimensional system of relations between the chains belonging to the various aspects. Modelling the integration of all available scientific knowledge and data is the only way to deliver adequate information for the policy preparation process. The EEA made use of this approach for its assessments of Europe's environment. Every three years the EEA will publish an "Assessment" and a "State of the Environment". The latest publication was "Europe's Environment: The Second Assessment", in June 1998 (EEA,1998). The next will be the "State of the Environment 1998" (EEA,1998), to be published in 1999. A prospective analysis forms part of the preparation of this report, in which modelling, based on the same DPSIR-approach is essential. The above-mentioned publications contribute to the preparation of new policy lines within the European Community.

Journal Article↗
PubMed1999

A regulatory view on science and predictive models.

A lot of scientific knowledge is required to carry out and enforce environmental regulations. The paper deals with the relationship between law and science from a legal perspective. First, some difficulties in using science to carry out environmental regulations are outlined. After this, some legal concepts which try to cope with the problems are presented. Aspects discussed are the precautionary principle, the legal concept of 'state of the art', general standard setting, the flexibility of the regulations, and procedural regulations for the standard-setting process. Finally, the new challenge for science that derives from the legal demand of an integrated approach to environmental protection is addressed.

Journal Article↗
PubMed1999

Predictive modeling of effects under global change.

The status of computer simulation models from around the world for evaluating the possible ecological, environmental, and societal consequences of global change is presented in this paper. In addition, a brief synopsis of the state of the science of these impacts is included. Issues considered include future changes in climate and patterns of land use for societal needs. Models discussed relate to vegetation (e.g. crop), soil, bio-geochemistry, water, and wildlife responses to conventional, forecasted changes in temperature and precipitation. Also described are models of these responses, alone and interactively, to increased CO(2), other air pollutants and UV-B radiation, as the state of the science allows. Further, models of land-use change are included. Additionally, global multiple sector models of environment, natural resources, human population dynamics, economics, energy, and political relations are reviewed for integrated impact assessment. To the extent available, information on computer software and hardware requirements is presented for the various models. The paper concludes with comments about using these technologies as they relate to ecological risk assessment for policy decision analysis. Such an effort is hampered by considerable uncertainties with the output of existing models, because of the uncertainties associated with input data and the definitions of their dose-response relationships. The concluding suggestions point the direction for new developments in modeling and analyses that are needed for the 21st century.

Journal Article↗
PubMedDate not supplied

Skin sensitization thresholds: determination in predictive models.

For many years, test methods for the prospective identification of skin sensitizing chemicals have been widely available. However, although these techniques have permitted the identification of the great majority of skin sensitizers, their use in assessing the relative potency of a particular chemical as a human contact allergen has not been well described. A primary reason for this is the inherent difficulty of such an exercise. A complex phenomenon involving interactions between the vehicle, the allergen, the skin and its inflammatory responses takes place during the induction and elicitation of sensitization. All these factors can have a profound effect on the threshold values determined for a skin sensitizer. Consequently, whether the assessment is conducted in humans or in animal models, a threshold concentration is always a function of the method of measurement as much as the potency of the allergen. Although an exhaustive review has not been carried out, this paper considers the attempts that have been made to assess relative potency by the measurement of dose-response relationships and the determination of induction and elicitation thresholds in both animal models and in humans. The latter has special relevance for regulatory toxicology and this matter is given particular attention in this article. Finally, recommendations are made: (a) that threshold concentrations for skin sensitizers should be determined on a case by case basis in relation to the likely mode of skin contact; (b) where the data are used in comparisons of skin sensitization potency, then there should be standardization of the method used for the determinations.

Animals↗
PubMed1995

Hospital falls: development of a predictive model for clinical practice.

A retrospective case-control study related to falls was conducted at an 1,120-bed acute care tertiary hospital. The case (fall) sample consisted of 102 falls and 236 control (nonfall) charts during a 1-month period. An instrument developed by Hendrich (1988) was modified for use in the study. Demographic data and risk factors were recorded. Descriptive statistics included risk factor percentages for each sample and the corresponding univariate relative risks. Logistic regression was used to develop a multivariate risk factor model with seven risk factors. The significant risk factors were recent history of falls, depression, altered elimination patterns, dizziness or vertigo, primary cancer diagnosis, confusion, and altered mobility. The adjusted relative risks were converted to risk points to be used to assess a patient's level of fall risk. Within the data set, a sensitivity of 77% (79 of 102) and specificity of 72% (169 of 236) were calculated. The model was cross-validated in a 1987 data set with a sensitivity of 83% (59 of 71) and specificity of 66% (106 of 161).

Accidental Falls↗
PubMed2001

Social approval and facilitation in predicting modeling effects in alcohol consumption.

PURPOSE: An important question for alcohol abuse prevention and treatment is whether individuals with high needs for social approval, or those who drink heavily in social contexts, are particularly vulnerable to modeling effects in alcohol consumption. METHODS: Male and female heavy social drinkers (N=202), as distinguished by these cognitive and situational variables, participated in a multisession dyadic modeling effects study along with a same-sex confederate model who exhibited alternating patterns of heavy and light consumption in an experimental barroom. RESULTS: Subjects with high needs for social approval, and those who tend to drink heavily in social contexts, were particularly vulnerable to imitating directional changes in modeled drinking levels across heavy and light consumption experimental sessions. Additionally, modeling effects were revealed, including reductions in drinking levels, regardless of individual characteristics such as demographics or levels of intoxication achieved on "usual drinking occasions." IMPLICATIONS: Findings suggest that individuals exhibiting high needs for social approval, and those who tend to drink heavily in social contexts, may benefit from (1) befriending lower risk models and (2) prevention and/or intervention efforts to reduce risk for substance use by reducing excessive needs for social approval and/or reducing exposure to social contexts where heavy drinking and related risk behavior is normative.

Adult↗
PubMedDate not supplied

Discrimination of glass sources using elemental composition and refractive index: development of predictive models.

Refractive index and metal ion concentrations (Al, Ba, Ca, Fe, Mg, Mn, Sr, Ti and Zr) were determined for four product-use categories: headlamp glass; container glass, non-vehicle window float glass, and vehicle float glass. Linear discriminant modelling using these data allowed differentiation of the four glass types but further discrimination was not possible within a product-use category. For this specific set of glasses, the concentrations of a number of metal ions were found to be correlated in some cases. This precluded the use of traditional probability calculations in using elemental composition data for interpretation of glass evidence. Alternative approaches to glass data interpretation are suggested.

Forensic Medicine↗
PubMed2005

Biochemical reaction network modeling: predicting metabolism of organic chemical mixtures.

All organisms are exposed to multiple xenobiotics, through food, environmental contamination, and drugs. These xenobiotics often undergo biotransformation, a complex process that plays a critical role in xenobiotic elimination or bioactivation to toxic metabolites. Here we describe the results of a new computer-based simulation tool that predicts metabolites from exposure to multiple chemicals and interconnects their metabolic pathways, using four common drinking water pollutants (trichloroethylene, perchloroethylene, methylchloroform, and chloroform) as a test case. The simulation tool interconnected the metabolic pathways for these compounds, predicted reactive intermediates, such as epoxides and acid chlorides, and uncovered points in the metabolic pathways where typical endogenous compounds, such as glutathione or carbon dioxide, are consumed or generated. Moreover, novel metabolites, not previously reported, were predicted via this methodology. Metabolite prediction is based on a reaction-mechanism-based methodology, which applies fundamental organic and enzyme chemistry. The tool can be used to (a) complement experimental studies of chemical mixtures, (b) aid in risk assessment, and (c) help understand the effects of complex chemical mixtures. Our results indicate that this tool is useful for predictive xenobiotic metabolomics, providing new and important insights into metabolites and the interrelationship between diverse chemicals that hitherto may have remained unnoticed.

Computer Simulation↗
PubMed2000

Posttraumatic stress disorder and retrospectively reported stressor exposure: a longitudinal prediction model.

There has been recent concern about the degree to which posttraumatic stress disorder (PTSD) symptomatology influences reports of prior exposure to highly stressful life events. In this longitudinal study of 2,942 male and female Gulf War veterans, the authors documented change in stressor reporting across 2 occasions and the association between change and PTSD symptom severity. A regression-based cross-lagged analysis was used to examine the relationship between PTSD symptom severity and later reported stressor exposure. Shifts in reporting over time were modestly associated with PTSD symptom severity. The cross-lagged analysis revealed a marginal association between Time 1 PTSD symptom severity and Time 2 reported stressor exposure for men and suggested that later reports of stressor exposure are primarily accounted for by earlier reports and less so by earlier PTSD symptomatology.

Adult↗