• Asian Pacific Journal of Cancer Prevention
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• v.15 no.6
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• pp.2461-2464
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• 2014

Background: Cancer accounts for 12.6% of total deaths in the world (just after heart disease). Materials and Methods: Frequency and age-specific incidence rates of breast and gynecologic cancers in Iran are calculated based on the dataset of the National Cancer Registry of Iran in 2005. Results: Gynecologic and breast cancer accounted for 7.6% and 25.6% of total cancer cases, respectively. Ovarian cancer was the most frequent gynecologic cancer followed by endometrium. Endometrial cancer revealed the highest age specific incidence rate followed by ovary (after 59 years). Conclusions: Regarding disease burden, breast and gynecologic cases account for 33.4% of total cancer patients. The age specific incidence rate is a useful guide in epidemiologic and future plans.

• The Korean Journal of Applied Statistics
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• v.25 no.3
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• pp.435-446
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• 2012

Epidemiologic studies frequently try to estimate the impact of a specific risk factor. The risk difference and the risk ratio are generally useful measurements for this purpose. When using such measurements for rare events, the standard approaches based on the normal approximation may fail, in particular when no events are observed. In this paper, we discuss and evaluate several existing methods to construct confidence intervals around risk differences and risk ratios using Monte-Carlo simulations when the disease of interest is rare. The results in this paper provide guidance how to construct interval estimates of the risk differences and the risk ratios when no events are detected.

• The Journal of the Korean dental association
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• v.45 no.3 s.454
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• pp.169-181
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• 2007

In this second part of series report on evidence-based dentistry, the level of evidence and the methods for critical appraisal are discussed. The epidemiologic studies, namely clinical studies have some bias per se, and the degree of bias is somewhat predetermined by the study design. The level of evidence can be defined as the reliability of the clinical study and it is dependent on the degree of bias. Thus, it is important to determine the type of the study and to understand its structure before critically appraising them. Systematic reviews of primary studies, randomized controlled trials, nonrandomized clinical trials, cohort studies, case-control studies, and case reports / series constitute the clinical studies and the level of evidence follows the order of the studies listed above. Critical appraisal is the most important procedure in evidence-based dentistry. It is done to determine the credibility of research papers and their usefulness in the clinician s own practice. Critical appraisal is consisted of multiple questions that are helpful for evaluating validity and usefulness of the studies concerning therapy, diagnosis, prognosis, and causation.

• Journal of environmental and Sanitary engineering
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• v.2 no.2 s.2
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• pp.61-67
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• 1987

The genus Vibrio contains some of the most important intestinal pathogens of humans, including Vibrio cholerae, the cause of epidemic Asiatic cholera. A group of organisms which have been reffered to as the non-agglutinating vibrio (NAG) do not agglutinate in the Vibrio cholerae 0 group 1 antisera, but are indistinguishable from the 0-1 group both chemically and genetically. Non-O-l Vibrio cholerae can cause isolated as well as focal outbreaks of diarrhea, but the volume of fluid loss does not approach that of classic cholera, and the disease is usually self-limiting. These free-living organisms are found world-widely distributed in the environment including sewage, contaminated water, estuaries, seafood and animals. These strains involved in several cases were isolated from the environment and some patients of diarrhea, and a few epidemiologic reports indicated the wide distribution of the strains throughout the country, giving an attention to the role the organisms may play in an outbreak of diarrhea in Korea. More research on the epidemiology, serologic typing and virulence of the group of organisms, should be, therefore, done to obtain a complete understanding of their role in human disease.

• 대한예방의학회:학술대회논문집
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• 1994.02b
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• pp.129-136
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• 1994

A model was developed for a simple clinical trial in which graders had defined probabilities of misclassifying pathologic material to disease present or absent. The authors compared Kappa between graders, and efficiency and bias in the clinical trial in the presence of misclassification. Though related to bias and efficiency, Kappa did not predict these two statistics well. These results pertain generally to evaluation of systems for encoding medical information, and the relevance of Kappa in determining whether such systems are ready for use in comparative studies. The authors conclude that, by itself, Kappa is not informative Enough to evaluate the appropriateness of a grading scheme for comparative studies. Additional, and perhaps difficult, questions must be addressed for such evaluation.

• Clinical and Experimental Pediatrics
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• v.62 no.8
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• pp.292-296
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• 2019

Epidemiologic studies of Kawasaki disease (KD) have shown a new pattern or change of its occurrence suggestive of its pathophysiology or risk factors from the first patient with KD reported in 1961. The incidence of KD in Northeast Asian countries including Japan, South Korea, China, and Taiwan is 10-30 times higher than that in the United States and Europe. Knowing the true epidemiology of KD in each country and the availability of publications of KD epidemiology also could benefit general health care providers and general population. This would enable the early detection and treatment of KD, ultimately reducing the incidence of coronary artery complications and mortality. Therefore, efforts to investigate the true epidemiology of KD should be continued in every country using a questionnaire survey, National Health Insurance system data, or combined methods depending on each country's medical environment to ensure high-quality care of patients with KD.

• 대한예방의학회:학술대회논문집
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• 1994.02a
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• pp.426-430
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• 1994

The assessment of exposure is an important component of the risk assessment process. Exposure information is used in risk assessment in at least two ways: 1) in the identification of hazards and the epidemiologic research investigating exposure-response relationships and 2) in the development of population exposure estimates. In both of these cases, the value of a chemical risk assessment is enhanced by improvements in the quality of exposure assessments. The optimum exposure assessment is the direct measurement of population exposure; however, such measurements are rarely available. Recent developments in methods for exposure assessment allow estimates to be made that are valid representations of actual exposure. The use of these exposure estimates to classify exposures correctly enhances the likelihood that causal associations between exposure and response will be correctly identified and that population risks will be accurately assessed.

• Journal of Environmental Health Sciences
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• v.40 no.4
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• pp.265-278
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• 2014

Microbes such as bacteria, fungi, archaea, protists, and viruses are ubiquitous and people are exposed to them continuously. Endotoxin is a component of the outer membrane of Gram-negative bacteria and a potent proinflammaotry substance. When a person is exposed to environmental endotoxin, an innate immune response is initiated upon the initial recognition and this response produces various inflammatory mediators and recruits inflammatory cells to the exposed tissues. A purified chemical form of endotoxin is called lipopolysaccharide (LPS), and the lipid A portion of the molecule is a biologically active moiety. Exposure to endotoxin may result in various complex health effects depending on time, route, and dose of exposure, as well as host susceptibility. Gene-environment interactions play important roles in health effects of endotoxin exposure, e.g. development or aggravation of asthma. To accurately assess exposure to endotoxin in environmental or epidemiologic studies, methods of sampling, extraction, and analysis must be carefully selected since the selected methods may substantially affect analytical results and there is no internationally-agreed standard method to date. The lack of a standardized method hampers the establishment of exposure-response relationships. While an internationally-agreed health-based exposure limit does not exist, the Dutch Expert Committee on Occupational Safety recently recommended $90EU/m^3$ as a health-based occupational exposure limit. The current article reviews various scientific issues on how we measure environmental endotoxin and the health effects of endotoxin exposure.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.7
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• pp.4177-4180
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• 2013

Background: The aim of this research was to perform an epidemiologic survey of esophageal cancer in Ardabil province. Materials and Methods: In this cross-sectional descriptive study, 661 patients diagnosed with EC were studied from March 2002 to May 2011 e. The necessary data were collected with a checklist from the documents in Ardabil Cancer Registry (ACR) and analyzed by statistical methods with SPSS.18 software. Results: Of the total new cases of EC registered in ARC during study period, 430 (65.1%) of patients were male with the male to female standard ratio was 1.18, with a statistically significant gender bias. The most common morphology of EC was squamous cell carcinoma (SCC, 68.8%) followed by adenocarcinoma (28.5%). It was observed that in most of patients, EC lesions were in the middle third of esophagus. In addition, most patients were rural and about 40% had smoking habits. The age-standardized incidence rate of cancers was 48.4 per 100,000 among females and males. The annual incidence rates in males and females was 7.1 and 6.7 per 100,000; respectively. Conclusions: Results showed that the prevalence and annual incidence rate of cancer in Ardabil province is lower than other areas of the country with a male predominance and a relatively high proprortion of adenocarcinomas.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.4
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• pp.1591-1597
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• 2015

Background: Korea has experienced rapid economic development in a very short period of time. A mixture of traditional and modern risk factors coexists and the rapid change in non-genetic factors interacts with genetic constituents. With consideration of these unique aspects of Korean society, a large-scale genomic cohort study-the Health Examinees (HEXA) Study-has been conducted to investigate epidemiologic characteristics, genomic features, and gene-environment interactions of major chronic diseases including cancer in the Korean population. Materials and Methods: Following a standardized study protocol, the subjects were prospectively recruited from 38 health examination centers and training hospitals throughout the country. An interview-based questionnaire survey was conducted to collect information on socio-demographic characteristics, medical history, medication usage, family history, lifestyle factors, diet, physical activity, and reproductive factors for women. Various biological specimens (i.e., plasma, serum, buffy coat, blood cells, genomic DNA, and urine) were collected for biorepository according to the standardized protocol. Skilled medical staff also performed physical examinations. Results: Between 2004 and 2013, a total of 167,169 subjects aged 40-69 years were recruited for the HEXA study. Participants are being followed up utilizing active and passive methods. The first wave of active follow-up began in 2012 and it will be continued until 2015. The principal purpose of passive follow-up is based on data linkages with the National Death Certificate, the National Cancer Registry, and the National Health Insurance Claim data. Conclusions: The HEXA study will render an opportunity to investigate biomarkers of early health index and the chronological changes associated with chronic diseases.