Principles and theories
Emily Ying Yang Chan in Disaster Public Health and Older People, 2019
Epidemiology is the study of the determinants and distribution patterns of disease and health outcomes in a population. This technical discipline presumes health outcomes in a population do not occur randomly, but follow a predictable pattern. Thus, although members of a population are exposed to the same health risks or environmental hazards, not everyone will be affected equally or suffer from their adverse health impact to the same extent (i.e. the varying distribution of health outcomes as affected by various factors). For example, if someone lives in a well-constructed, earthquake-resistant concrete building, the risk of this individual being injured by the building collapsing during an earthquake is likely to be lower than for those who live in makeshift lumber-and-brick shelters. Through epidemiological analysis, risk factors identified will help explain why certain communities are more prone to the negative health impact of disasters and protective measures may be developed to protect these vulnerable groups before a disaster strikes.
The Ecology of Parasitism
Eric S. Loker, Bruce V. Hofkin in Parasitology, 2015
The disciplines of epidemiology and ecology have much in common. Both seek to understand patterns in the distribution and abundance of organisms (such as a particular parasite species that causes a human disease), and both are interested in revealing the processes (determinants) that underlie the patterns. The goal of epidemiology is often to identify risk factors and to anticipate and prevent disease outbreaks. Epidemiological studies are often undertaken in the context of human public health, but epidemiologists also study disease outbreaks in different kinds of hosts, ranging from oak trees to honeybees to horses. For example, the term epizootiology refers to the study of the distribution and determinants of disease in animals. Epidemiologists are interested in a triad of factors (host, parasite, and environment) and how they intersect to create the opportunity for disease transmission.
Limitations of epidemiologic exposure studies on the health effects of asbestos
Dorsett D. Smith in The Health Effects of Asbestos, 2015
Epidemiologic studies are usually divided into four types: Cohort studies, or a prospective observational study, of a group that is exposed to asbestos as compared with a group not exposed to asbestos, and then following their outcomes over a defined period. The results in cohort studies are commonly expressed as the (RR; risk ratio), meaning the incidence of disease in the exposed group divided by the corresponding incidence in the unexposed group.Case–control studies are retrospective studies evaluating groups, in which a certain outcome such as mesothelioma is compared to a control group without a mesothelioma and then determining risk factors for the disease. The data are commonly expressed as the odds ratio (OR) or the odds of exposure in the group with disease as compared to the control group.Cross-sectional studies are observational studies that evaluate the absence or presence of an exposure and disease at a specific time.Case reports, or case series, are descriptive reports on a single case or series of cases with a specific disease and a specific exposure reported to raise a hypothesis, but they cannot test a hypothesis because they do not include an appropriate comparison group.
Extinction and persistence of a stochastic delayed Covid-19 epidemic model
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
Amir Khan, Rukhsar Ikram, Anwar Saeed, Mostafa Zahri, Taza Gul, Usa Wannasingha Humphries
Epidemiology is the study of the determinants, occurrence, and distribution of health and disease in a defined population. The importance of this field can be seen in the fact that its interest is growing day by day. Therefore, many mathematical models have been created in the past, such as SI, SIR, H1N1, HBV, SIS model, SARS, SIER model, H5N1, etc., as you can see in Kermack et al. (1927), Billard and Dayananda (2014), and Pongsumpun and Tang (2014). All these problems have been formulated mathematically to make realistic predictions and provide information to society about the diseases which are helpful for a stable society and stable health (Upadhyay et al. 2008; Naheed et al. 2014; Din et al. 2020). The stability and prevention of various diseases in human population societies are important and necessary issues. After the first attempt of Mckendrick and Kermack (Kermack et al. 1932; Khan et al. 2021), the mentioned models for the control of various diseases were analyzed in detail. Based on this approach and the basic concepts, different researchers have modified and developed the epidemic models by including vaccine class and time delay (Edmunds et al. 1996; Atangana and Koca 2016; Ullah et al. 2018; Danane et al. 2020; Din et al. 2020; Khan et al. 2021).
Toward a science-based testing strategy to identify maternal thyroid hormone imbalance and neurodevelopmental effects in the progeny – part I: which parameters from human studies are most relevant for toxicological assessments?
Published in Critical Reviews in Toxicology, 2020
Ursula G. Sauer, Alex Asiimwe, Philip A. Botham, Alex Charlton, Nina Hallmark, Sylvia Jacobi, Sue Marty, Stephanie Melching-Kollmuss, Joana A. Palha, Volker Strauss, Bennard van Ravenzwaay, Gerard Swaen
Epidemiology is the discipline addressing the distribution of disease among human populations thereby aiming at identifying its causes and contributory factors (Hajat 2011). The scientific methodologies available in epidemiology are fundamentally different from those available for toxicological assessments. Toxicologists assessing chemical-induced effects can apply experimental study designs and testing strategies using a broad spectrum of test methods, many of which are standardised and adopted as internationally agreed formal guidance. By contrast, epidemiologists, when evaluating human health effects potentially caused by chemical exposure, are nearly always limited to non-experimental, observational study designs (WHO IPCS 2004), and the types of health parameter measurements that can be made are much more restricted than e.g. in regulatory toxicology.
Epidemiology of major chronic inflammatory immune-related skin diseases in 2019
Published in Expert Review of Clinical Immunology, 2020
The final aim of epidemiologic research is to find ways to prevent the onset of a disease and/or influence its natural history, by acting on environmental risk factors. Such an issue is particularly important for common diseases posing a high economic burden as are ISDs as a whole. We are far from preventing ISDs or even reducing their increase in incidence. At this stage, the only risk factor for which there is proof that a modification can result in reduced severity and consequent disability, has been overweight/obesity in relation with psoriasis. Unfortunately, the evidence has not been translated into changes in healthcare provision. Research is needed to look at barriers for implementation of preventive measures. There is also a need to develop research on risk factors for ISDs in a more systematic way, taking into account genetic-environmental interactions.
Related Knowledge Centers
- Clinical Research
- Disease Surveillance
- Environmental Epidemiology
- Statistical Inference
- Risk Factor
- Public Health
- Preventive Healthcare
- Pathogen Transmission
- Disease Outbreak
- Forensic Epidemiology