Trend of Mortality Rate and Injury Burden of Transport Accidents, Suicides, and Falls / 예방의학회지

OBJECTIVES: Recently injury has become a major world-wide health problem. But studies in Korea about injuries were very few. Thus, this study was conducted to analyze the trend of major injuries from 1991 to 2006 and to provide basic data for preventing injuries. METHODS: This study was based on the National Statistical Office data from 1991 to 2006 and calculated to estimate the burden of major injuries by using the standard expected years of life lost (SEYLL) and total lost earnings equation. RESULTS: For transport accidents, mortality, SEYLL and total lost earnings were increased from 1991 to 1996 and decreased from 2000 to 2006. On the other hand, for suicides, these were increased gradually. Since 2003, falls were included in ten leading causes of death. This study showed that injury causes major social and economical losses. CONCLUSIONS: We could reduce injury related premature death through active interest in injury prevention program.

Community and Hospital Onset Methicillin-resistant Staphylococcus aureus in a Tertiary Care Teaching Hospital / 병원감염관리

BACKGROUND: This study evaluated the clinical characteristics and risk factors associated with community and hospital onset MRSA isolated from patients admitted to a tertiary care teaching hospital. METHODS: The study was carried out on MRSA isolated from clinical specimens of patients admitted into the wards and the intensive care unit in a 2,200-bed tertiary care teaching hospital from January 1st through December 31st, 2007. In order to identify the risk factors associated with MRSA acquisition, the medical records were reviewed. All statistics were computed using SPSS version 14.0. RESULTS: Of the 835 MRSA isolates, 179 (21.4%) were CO-MRSA and 656 (78.6%) were HO-MRSA. Of the 179 CO-MRSA isolates, 6 (3.4%) were CA-MRSA. Multiple logistic regression analysis showed that a history of using medical device or antibiotics within 1 year before the isolation of MRSA were significant risk factors for HO-MRSA, and a history of hospitalization within 1 year before the isolation of MRSA was a significant risk factor for CO-MRSA. Analysis on the antibiotics administered within 1 year before the isolation of MRSA showed that levofloxacin, macrolides, 1st generation cephalosporins, 3rd generation cephalosporins, 4th generation cephalosporins, vancomycin, metronidazole, and carbapenem were all significant risk factors for HO-MRSA and that TMP/SMX was a significant risk factor for CO-MRSA. Of the 6 (3.4%) CA-MRSA isolates, 1 (16.7%) was the pathogen responsible for soft tissue infection. No patients died from the CA-MRSA infection. CONCLUSION: MRSA isolated from clinical specimens of patients admitted into the wards and the ICU in a tertiary care teaching hospital was usually HO-MRSA, CO-MRSA and HO-MRSA usually had at least one of the risk factors associated with MRSA acquisition, and CO-MRSA was mainly HACO-MRSA.

Prevalence of vanA Vancomycin-Resistant Enterococci and Epidemiologic Survey of Chicken Farms Located in Seoul and Kyunggi Province / 병원감염관리

BACKGROUND: Avoparcin has been banned in Korea since 8 years ago, but vancomycin-resistant enterococci (VRE) has not been proven to be eradicated from the domestic livestock. This study was purposed to investigate the prevalence of VRE and perform an epidemiologic survey in chicken farms located in Seoul and Kyunggi Province. METHODS: Feces were collected freshly from chickens and workers and their families in three free-range chicken farms and three cage-raising chicken farms. All swabs were inoculated on enterococcosel agar containing 6 microgram/mL of vancomycin. Minimum inhibitory concentrations of teicoplanin and vancomycin were determined using the agar dilution method. Vancomycin resistance were genotyped with multiplex PCR using primers specific for vanA, vanB, and vanC1. Epidemiolgic survey was carried out using a uniform questionnaire to obtain information about the number and variety of livestock, feeding protocols, physical farming conditions, maintenance protocols, hygiene, and employment conditions. RESULTS: vanA Enterococcus facium was isolated from 37 (2.9%) of 1280 chickens. There were no VRE carriers found among the workers and their families. The prevalence of VRE among cage-raising chickens was 4.8% compared to 0.6% for free-range chickens. The difference between the two groups was highly significant (P<0.001). CONCLUSION: There still was a significant rate of VRE colonization in chicken livestock in Seoul and Kyunggi Province. Physical farming conditions of cage-raising chicken farms seemed to be associated with a high VRE colonization rate.

Prevalence of vanA Vancomycin-Resistant Enterococci and Epidemiologic Survey of Chicken Farms Located in Seoul and Kyunggi Province / 병원감염관리

BACKGROUND: Avoparcin has been banned in Korea since 8 years ago, but vancomycin-resistant enterococci (VRE) has not been proven to be eradicated from the domestic livestock. This study was purposed to investigate the prevalence of VRE and perform an epidemiologic survey in chicken farms located in Seoul and Kyunggi Province. METHODS: Feces were collected freshly from chickens and workers and their families in three free-range chicken farms and three cage-raising chicken farms. All swabs were inoculated on enterococcosel agar containing 6 microgram/mL of vancomycin. Minimum inhibitory concentrations of teicoplanin and vancomycin were determined using the agar dilution method. Vancomycin resistance were genotyped with multiplex PCR using primers specific for vanA, vanB, and vanC1. Epidemiolgic survey was carried out using a uniform questionnaire to obtain information about the number and variety of livestock, feeding protocols, physical farming conditions, maintenance protocols, hygiene, and employment conditions. RESULTS: vanA Enterococcus facium was isolated from 37 (2.9%) of 1280 chickens. There were no VRE carriers found among the workers and their families. The prevalence of VRE among cage-raising chickens was 4.8% compared to 0.6% for free-range chickens. The difference between the two groups was highly significant (P<0.001). CONCLUSION: There still was a significant rate of VRE colonization in chicken livestock in Seoul and Kyunggi Province. Physical farming conditions of cage-raising chicken farms seemed to be associated with a high VRE colonization rate.

Epidemiology of Hemorrhagic Fever with Renal Syndrome in Endemic Area of the Republic of Korea, 1995-1998

We conducted an epidemiologic study to understand temporal and spatial patterns of hemorrhagic fever with renal syndrome (HFRS) in the Republic of Korea (ROK). We estimated the incidence among civilians in endemic areas through the active surveillance system during the major epidemic periods, from September to December, between 1996 and 1998. We also estimated the prevalence among Korean military personnel from 1995 to 1998. In addition, we assessed seroprevalence, subclinical infection rate, and vaccination rates in both civilians and military personnel. The incidence in civilians ranged from 2.1 to 6.6 per 100, 000 person-months. The annual prevalence in the military personnel was 40-64 per 100, 000 military populations, and remained generally constant throughout the study period with seasonal variation. This is the prospective epidemiologic data set on HFRS in the ROK since the inactivated Hantaan virus vaccine was licensed for use in the late 1990s. These results will be invaluable in establishing a national immunization program against HFRS.

Study of nosocomial pneumoniae in ICU of a hospital / 한국역학회지

PURPOSE: As a retrospective study by using of medical records, this was to investigate the incidence rate of nosocomial pneumonia and risk factors and to determine the causing agent. METHODS: Subjects were 336 patients during the period from January 2003 through December 2003. Nosocomial pneumonia was defined according to the definition(CDC, 1992).The statistical SPSS was used to analyze data that included chi-square, t-test and multiple logistic regression. RESULTS: The actual number of patients with nosocomial pneumonia turned out to be 42 out of total 336 patients during the survey period. The incidence rate was 125 per 1,000 patients and 16.7 patients per 1,000 patient-days, which is comparable with 217 patients with ventilator-associated pneumonia per 1,000 patients and 34.8 per 1,000 patient-days. The significant risk factors for nosocomial pneumonia were identified as cardiomegaly based on chest radiography (OR=4.93; 95% CI=1.11-21.94), cerebral hemorrhage(OR=6.27; 95% CI=1.63-24.16), cerebral infarction(OR=4.39; 95% CI=1.05-18.40) and the duration of admission (OR=5.57; 95% CI=3.14-9.88). Causing agents of nosocomial pneumonia were Staphylococcus aureus 21.8%, Pseudomonas aeruginosa 17.4% and Acinetobacter baumani 17.4%. Ventilator-associated pneumonia were Acinetobacter baumani 27.5%, Staphylococcus aureus 24.2%, Pseudomonas aeruginosa 13.8%. CONCLUSIONS: The cardiomegaly at admission, diagnosis and duration of admission were considered to enhance the incidence rate of nosocomial pneunoniae. Further studies and intervention actions would be necessary to deal with the nosocomial pneunoniae.

A Study on the Academic Paper Review Process of Medical Societies / 대한의료정보학회지

The subjects in this study were the directors in charge of article inspection from 127 academies that are registered with the Korea Academy of Medical Science. After a questionnaire was prepared covering the examination process, judging committee organization, problems with examination and possible reform measures, a survey was conducted by e-mail and facsimile from October 4 through 20, 2001. The responses from 79 academies were gathered, a response rate of 62.2%, and the collected data were analyzed with SAS. The most common examination process was C type, which convenes publishing committees, employed by 59 academies_(74.6%), and these institutes found it satisfactory. Thirty-four academies_(43.0%) had 10 to 19 judges, and these judges were separately in charge of different fields, whereas 79 academies_(77.3%) allocated five or less judges to each field. Thirty_(38.0%) academies had their judges comply with related official directions or guidelines, and 50 academies_(63.3%) conducted investigation just twice. Fifty-four academies_(68.4%) weren't satisfied with their examination process. As for the problems with the examination process, many_(41.8%) pointed out that it's time-consuming work and that a lot of procedures were repeated. Concerning the benefit of the online examination program, 41 academies_(51.9%) thought that it was more efficient and less time-consuming. Forty-one academies_(51.9%) were aware of the online examination program, but only 23 academies_(29.1%) were willing to use it. In order to realize an online paper review, there should be appropriate criteria and guidelines for the construction of an online paper review system that suits various types of paper review process employed by the academies. The usability of online information and technology for more efficient and higher-quality judgment should be widely be publicized, and consideration should be given for the types of paper review system that might be suitable for those who are neither aware of the use of the internet nor willing to utilize.

A Study for Effects of Economic Growth Rate and Unemployment Rate to Suicide Rate in Korea / 예방의학회지

OBJECTIVES: We investigated the effects of the economic growth and unemployment rates on the suicide rate in Korea, between 1983 and 2000, using a time-series regression model. The purpose of this study was to model and test the magnitude of the rate of suicide, with the Korean unemployment rate and GDP. METHODS: Using suicide rate per 100, 000 Koreans and the unemployment rates between 1983 and 2000, as published by the Korea National Statistical Office, and the rate of fluctuation of the Korean GDP (Gross Domestic Product), as provided by the Bank of Korea, as an index of the economic growth rate, a time-series regression analysis, with a first-order autoregressive regression model, was performed. RESULTS: An 81.5% of the variability in the suicide rate was explained by GDP, and 82.6% of that was explained by the unemployment rate. It was also observed that the GDP negatively correlated with the suicide rate, while the unemployment and suicide rates were positively correlated. For subjects aged over 20, both the GDP and unemployment rate were found to be a significant factors in explaining suicide rates, with coefficients of determination of 86.5 and 87.9%, respectively. For subjects aged under 20, however, only the GDP was found to be a significant factor in explaning suicide rates (the coeficient of determination is 38.4%). CONCLUSION: It was found that the suicide rate was closely related to the National's economic status of Korea, which is similar to the results found in studies in other countries. We expected, therefore, that this study could be used as the basis for further suicide-related studies.

Analysis of the Characteristics Appeared in the Cancer Information Provided as a Form of Question and Answer on the Internet / 대한의료정보학회지

This study was carried out to investigate the characteristics of contents and utilization for cancer information that is serviced on the internet in the form of Q&A and FAQ. A total of 947 cases (340 in Q&A and 607 in FAQ) were collected from August 20th to November 20th, 2001. Data were analyzed with descriptive statistical methods regarding the type of service, contents, and cancer included in the contents. The prevalent pattern of cancer information service was FAQ, and the distribution of contents and kind of cancer that were serviced differed depending on their service pattern and resources. The contents for prevention and screening, general understanding of cancer, and rehabilitation appeared more often in FAQ than in Q&A and were also more frequent in cancer specialized websites than any others. This pattern may be because FAQ and cancer specialized websites have a view of contents provider. Clinical symptoms and diagnosis were the contents provided more frequently in Q&A than in FAQ. Additionally, information on breast cancer was the most frequently asked question in regard to major cancer in Korea. However, information on hematopoietic system was the most frequently asked in Q&A. From the results of this study, it is clear that cancer-related information varies according to the cancer types, service patterns, and website characteristics. However, the fundamental difference depends on whether the contents are created in terms of the information user or not. This study demonstrated that there is a difference between users and developers in the requested information regarding available cancer-related. It is therefore necessary to establish a basic plan for appropriate cancer information services according to the needs of the users.

An Epidemiologic Study on the Nosocomial Bloodstream Infection in Two Hospitals / 한국역학회지

PURPOSE: In this study, nosocomial bloodstream infection rate and fatality rate for 774 and 386 patients, who whose blood cultivation were obtained after 48 hours of hospitalization between March 1999 and February 2000 in two university hospitals, were sought. A distribution of etiologic agent and risk factors of the nosocoial bloodstream infection were also investigated. METHODS: This study was carried out through medical record review and a structural questionnaire. Besides registers of microbe cultivation in the department of clinical pathology and medical records of patients were checked. The nosocomial bloodstream infection was also checked through medical records of patients using the standard of CDC. Statistical analysis were performed using SAS 6.12. RESULTS: The nosocomial bloodstream infection rate in hospital K and hospital A were 3.9 and 3.5 per 1,000 discharged patients, respectively. Although the rates were increased accoding to patients' age, they were different by medical departments, showing the highest level in the ICU. The fatality rate from nosocomial bloodstream infection in hospital K and hospital A were 12.5% and 21.8%, respectively. A distribution of etiologic agent of the nosocomial bloodstream infection in hospital K was 17 cases(21.8%) of Coagulase negative staphylococcus(CNS), 12 cases(15.0%) of Staphylococcus aureus and 8 cases(10.0%) of Enterococcus spp. For hospital A, it was 14 cases925.4%) of Coagulase negative taphylococcus(CNS), 9 cases(16.4%) of Staphylococcus aureus and 7 cases(12.7%) of Klebsiella pneumoniae. While risk factors of the nosocomial bloodstream infection edentified in hospital K were ICU, intracranial injury and hospitalization period, those for hospital A were a use of the central nenous tube, intracranial injury and hospitalization period. CONCLUSION: It is expected that nosocomial bloodstream infection increases as aged group increases by the change of the population structure, as the usage of invasive instrument increases by development of new medical instrument as well as large scale hospitals. For these reasons, further studies developing countermeasures against nosocomial bloodstream infection are recommended.

Heart Diseases Prevalence of Elementary School Children in Kyonggi Province / 예방의학회지

OBJECTIVE: The heart diseases are known as a major cause of sudden death, as well as a cause of poor life-quality of school-age children. But there have been few mass screening of heart diseases in these children in Korea. This study was done to estimate the prevalence of heart diseases of these population. METHODS: We screened all elementary students(grade 1) in 12 cities and 16 counties(Gun) in Kyonggi province from 1992 to 1995. The first screening was done by auscultation of doctors and simultaneously by checking using 'auto-interpreter of EKG-cardiac sound'(Fukuda Densi ECP 50A). We conducted futher examinations to whom classified as being abnormal condition in first screening, by using EKG, chest x-ray, doppler echocardiograpy(if needed). RESULTS: The total number of examined students was 161,308(92% of the population), the male were 83,238 and female were 78,070. The congenital heart diseases(CHD) patients were 290(18 per 10,000) - male 155(18.6 per 10,000) and female 135(17.3 per 10,000). The most frequent disease was ventricula septal defect(VSD, 45.5%), Atrial septal defect(ASD, 14.8%), Tetralogy of Follot(TOF, 11.7%), and Patent Dutus Arteriosis(PDA, 7.6%) in order. In female, the order was VSD(48.1%), ASD(13.3%), TOF(11.1%), and PDA(10.4%). The total number of EKG abnormality were 433(62.7 per 10,000) among 69,056 screened children in 1995. The complete right bundle branch block(CRBBB) and paroxymal ventricular contraction(PVC) were frequent(26.6%, 26.3% in each), and incomplete right bunddle branch block(IRBBB,14.6%), paroxymal atrial contraction(PAC, 6.7%), abnormal Q(5.8%), Wolf-Pakinson-White syndrom (5.5%) in order. In female, the most frequent abnormality was PVC(29.8%), and CRBBB(19.9%) in order. CONCLUSION: We could present the stable prevalence of the rare heart disease. The prevalence of congenital heart diseases was 18.0 per 10,000 and of EKG abnormality was 62.7 per 10,000 among school children.

Activities of Hospital Infections Program in the United States / 병원감염관리

No Abstract available.

A Population-Based Case-Control Study on the Risk Factors of Congenital Heart Malformations / 한국역학회지

The multifactorial hypothesis is proposed as a working hypothesis which encompass both the genetic and environmental factors known to participate in the etiology of congenital heart malformations. So, it is believed that avoidance of suspected environmental factors in early pregnancy is the most certain preventive measure of congenital heart malformations. This study has been undertaken in order to find the possible environmental risk factors for congenital heart malformations in Korea. A total of 114 mothers of first graders of the elementary schools with congenital heart malformations confirmed through the screening program in Kyonggi Province from 1992 to 1995 were included as cases. And 206 mothers of healthy students matched by sex and elementary schools comprised the control group. Environmental risk factors including drug use during the first trimester of pregnancy, and other confounders were collected by telephone interview using standardized questionnaires by well trained interviewers. The result of multivariate logistic regression analysis showed that congenital heart malformation were associated with family history of congenital heart malformations(OR=2.94, 95% CI: 1.08, 7.96), the order of birth(OR=0.49, 95% CI: 0.31, 0.79). And the coffee consumption over 14 cups/week during early pregnancy showed marginal significance(OR=3.52, 95%CI: 0.98, 12.62). The mother's age at the subject birth and father's smoking at home were significant in linear trend test(p<0.05). It is recommended that the genetic counselling and the avoidance of known environmental risk factors in early pregnancy were needed to prevent congenital heart malformations.

Occupational Dermatoses in Metalworking Fluid Exposed Workers . ( II ) Allergic Contact Dermatitis / 대한피부과학회지

BACKGROUND: Skin contact with metalworking fluid(MWF) remains a frequent cause of occupational dermatitis. However, no precise data is available about sensitization in metalworkers exposed to MWF in Korea. OBJECTIVES: The purpose of this study was to evaluate the prevalence of contact sensitivity among metalwokers who handle MWFs and to investigate the suitability of a screening test with MWFs being actually used in metalworkers. METHODS: An epidemiological study was performed using a'questionnaire in 771 workers in 9 derpartments of a motor company. 278 out of 771 workers had actual contact with MWF. Patch tests were performed in 73 metalworkers who had suspected dermatits in relation to exposure of MWF, which was selected via interviews and dermatologic examinations. Patch tests were included with a routine series of common components of MWF(materials obtained from Chemotechnique, Sweden), a solvent series and several dilutions of various crude MWFs(8 species) RESULTS: Contact sensitization was established in 14 metalworkers(5% of 278). Sensitising substances were biocide(6 cases), corrosion inhibitors(2 cases), emulsifiers(2 cases), biostatic substances(1 cses) and others(4 cases). Therefore 10 out of 14 metalworkers had true occupational allergic contact dermatitis. 10 out of 73 screening patch tests showed positive reactions to MWF elements, and 9 people who were positive to MWF elements showed positive reactions to crude MWF, but 1 person did not. CONCLUSION: The prevalence of occupational allergic contact dermatitis(3.5% of 278) was low. The screening patch test by crude MWFs actually used in metalworkers may give false negatives. Therefore for the purpose of diagnosis of allergic contact dermatitis, we need a process of patch tests with MWF elements.

Indigenous Malaria Surveillance in Korea / 한국역학회지

Malaria, one of the compulsory notifiable diseases, has been diappeared from Korea based on that fact no notification on malaria case was received from local health agencies during the last decade or so. Recently, Indigenous malaria has been re-emerged since 1993 and 549 cases was notificated till 1996. We conducted a surveillance system on the resurgent malaria outbreaks in the northern area of Kyonggi Province around the Imjin River. Malaria Surveillance Networks(MSNs) were established in Paju and Yoncheon between August 1996 and December 1996. When a febrile patient visits a clinic or a hospital, clinician takes a blood sample and refer to district malaria laboratory for the sample. The blood sample is examined in the malaria laboratory(public health center), and if malaria parasites are found, a radical or curative treatment is offered to patients. MSNs took 94 febrile cases and identified 23 malaria cases(24.5%). All malaria cases were infected by the indigenous vivax malaria. In Paju, 14 of 62 febrile cases(22.6%) were malaria outbreaks and 9 of 32 febrile cases(28.1%) in Yoncheon. In Korea resurgent malaria, malaria surveillance system should be operated for a program based on the district public health center with the coupled laboratory and dispensary.

Diagnosis of Tertian Malaria Using Acridine Orange Stain / 감염

BACKGROUND: In South Korea, indigenous malaria has been reappeared since 1993 and more than 350 cases diagnosed in 1996. For the diagnosis of malaria the classic methods such as thin and thick blood smears with Giemsa or Wright stain has been routinely used. Since recently fluorochrome staining has been shown to be more sensitive, easy to do, and less time-consuming, we applied the new method, Acridine orange stain, for diagnosis of clinically suspected cases. METHODS: Thin and thick blood smears were prepared from civilian patients of Kyunggi Province (n=20) and Republic Of Korea army patients pre- (n=67) and post-treatment (n=13) of malaria. The slides were fixed by methanol and stained by either Giemsa or Acridine orange solution (10-50 g/mL). For comparison, an expert on malaria diagnosis examined them by light and fluorescent microscope, respectively. RESULT: Acridine orange stain was found to be a rapid technique, and as sensitive (83%) as thick smears (83%) for diagnosis of malaria. The detection limit of acridine orange stain was 23.5 parasites/ul of blood. The staining time was much shorter (30 sec) than that of Giemsa stain (30-60min). CONCLUSION: Acridine orange stain is evaluated as a simple, rapid, and sensitive method for malaria diagnosis compared with Giemsa stain.

Evaluation of Mercury Concentration in Spot Urine for Biological Monitoring Among Metallic Mercury Exposed Workers / 대한산업의학회지

Biological monitoring for exposures permits estimation of organ doses or body burdens from exposures through all relevant portals of entry. Biological monitoring data may be used to estimate environmental concentrations when the latter cannot be measured directly. Biological indices are usually surrogates for the concentration of a chemical or its metabolites or its effect at the true receptors. Mercury concentration in urine has-been most-coinmoialy-recommended as a biological exposure index of mercury. For data based on urine analysis, variation in urine volume is the most significant. The urinary concentration related to excretion of the solute provides some correction for fluctuation of urine output. Sampling time must be carefully observed because distribution and elimination of a chemical are kinetic events. This study has evaluated mercury concentration in spot urine compared to the results of 24 hour collected urine by the adjustment methods (specif ic gravity, creatinine) and sampling time. The subjects were 43 workers who had been exposed to the metallic mercury. The results were as follows: 1. The correlation coefficients between mercury concentration in 24 hour urine and that in spot urine were 0.639-0.715 and were not different by adjustment methods. 2. In the high exposure group who were over lOOug/1 of urinary mercury, the correlation coefficients between mercury concentration in 24 hour urine and that in spot urine were 0. 687-0.824 and were not different by adjustment methods. 3. Mercury concentration in spot urine were very variable by sampling time or exposure time. The correlation coefficients between mercury concentration in 24 hour urine and that in spot urine were most highest as 0.85-0.91 at first voiding urine in the morning, and were 0. 77-0.86 at urine collected within four hours before end of shift. In the biological monitoring to exposure of mercury, sampling of spot urine were most proper at first voiding urine in the morning, and then at urine collected within four hours before end of shift. But the adjustment methods of specific gravity and creatinine were no difference of the results.

A study on dermatologic diseases of workers exposed to cutting oil / 예방의학회지

We investigated the 1,004 workers who worked in a automobile factory to study the epidemiologic characterist of dermatoses due to cutting oils. Among the workers, 667(66.4%) answered the questionnaire. They are belong to 5 departments of the factory-the Engine-Work(86), Power train Assembly(17). We measured the oil mist concentration in air of the departments and examined the workers who had dermatologic symptoms. The results were follows; 1) Oil mist concentration; Of all measured points(52), 9 points(17.2%) exceeded 5mg/m3-the time-weighed PEL- and one department had a upper confidence limit(95%) higher than 5mg/m3. 2) Dermatologists examined 213 workers. 172 of them complained any skin symptoms at that time-itching(32.5%), papule(21.6%), scale(15.7%), vesicle(12.5%) in order. The abnormal skin site found by dermatologist were palm(29.3%), finger & nail(24.6%), forearm(16.2%), back of hand(8.4%) in order. 3) As the result of physical examination, we found that 160 workers had skin diseases. Contact dermatitis was the most common; 69 workers had contact dermatitis alone(43.1%), 11 had contact dermatitis with acne(6.9%), 10 had contact dermatitis with folliculitis(6.3%), 1 had contact dermatitis with acne & folliculitis, and 1 had contact dermatitis with abnormal pigmentation. Others were folliculitis(9 workers, 5.6%), acne(8, 5.0%), folliculitis & acne(2, 1.2%), keratosis(1, 0.6%), abnormal pigmentation(1, 0.6%), and non-specific hand eczema(47, 29.3%). 4) The prevalence of any skin diseases was 34.0 per 100 in cutting oil users, and 13.3 per 100 in non-users. Especially, the prevalence of contact dermatitis was 23.0 per 100 in cutting oil users and 4.3 per 100 in non-users. 5) We tried patch test(standard series, oil series, organic solvents) on 49 patients to differentiate allergic contact dermatitis from irritant contact dermatitis and found 20 were positive. 6) In a multivariate analysis(independent=age, tenure, kinds of cutting oil), the risk of skin diseases was higher in the water-based cutting oil user and both oil user than non-user or neat oil user(odds ratio were 2.16 and 2.78, respectively). And the risk of contact dermatitis was much higher at the same groups(odds ratio were 5.16 and 6.82, respectively).

Cohort Study / 한국역학회지

The cohort study is an observational epidemiological study which selects the specific study population attempting to study the relatiqnship between an exposure to the purported cause and the subsequent risk of developing disease in accordance of time direction. Since Doll and Hill had studied the association between lung cancer and smoking behavior among the British medical doctors in the years of the last fifties, the defined group cohort studies analysing the relationship between an exposure and the occurence of a disease have become very popular. Cohort studies can be classified as either prospective or retrospective, depending on the temporal relationship between the initiation of the study and the occurence of the disease. Cohort studies are admitted as the very valuable studies for demonstrating the association between an exposure and a disease because it is possible to drive relative and attributable risks and often incidence measures. They can even examine multiple effects of a single exposure. However, they are usually expensive to carry out and large cohorts are required for rare diseases in addition to the time consum ing works. There are also very significant problems associated with selection of appropriate groups to be studied as far as complete ascertainment of disease occurence in them. Usually it is necessary that we must compromise to provide the opportunity for various types of bias such as selection bias, follow-up bias, information bias or misclassification, confounding bias and post hoc bias to occur which can result in incorrect conclusions. Only the success of a cohort study would be expected when the investigator pay the deep care in recognizing and correcting for these biases.

Reference(cut-off) values of serum total cholesterol for risk groupof atherosclerosis among normal adults in Korea

No abstract available.