Treatment of the Posterior Circulation Aneurysms / 대한뇌혈관외과학회지

OBJECTIVE: Endovascular treatment is now accepted as an initial treatment modality, especially in cases of posterior circulation aneurysms. The purpose of this study was to review the treatment outcomes and to emphasize the necessity of maintaining the surgical ability for posterior circulation aneurysms. METHODS: During the past 10 years, 570 patients have been treated for cerebral aneurysms at our institute. Among these patients, 34 harbored posterior circulation aneurysms. From January 2004 to June 2008, 13 of the 34 patients were treated by endovascular coiling. We retrospectively reviewed the clinical outcome, cerebral angiograms, and other radiological imagings through a comparative study of the pre- and post-endovascular treatment periods. RESULTS: Overall, 9 (69.2%) of the pre-endovascular treatment period group and 20 (95.2%) of the endovascular treatment period group had good outcomes. The mean post-operative hospital days for these groups were 38.6 and 21.1, respectively. Patients in the endovascular treatment period group had shorter post-operative hospital periods and better outcomes than those in the pre-endovascular treatment period group. CONCLUSION: It is recommended that multimodality treatment involving microsurgical clipping and endovascular coiling is used to obtain better results in the treatment of posterior circulation aneurysms. These results suggest that although the trend toward endovascular treatment as the initial aneurysm therapy for posterior circulation aneurysms is also enhancing, it might be necessary to maintain the surgical ability for posterior circulation aneurysm.

The Analysis of Tumor Aggressiveness accord- ing to Tumor Size in Occult Papillary Thyroid Carcinoma

PURPOSE: Occult papillary thyroid carcinomas (OPC) are defined as tumors measuring 0.5 cm. A near-total or total thyroidectomy with a central lymph node dissection is the preferred treatment. The early detection and treatment of OPC might be warranted through the routine use of thyroid USG and USG-guided FNA.

The Factors Associated with the Abnormal Eating Behavior in University Hospital's Nurses / 한국역학회지

OBJECTIVES: To compare eating behavior according to the shift work and to find the factors associated with the abnormal eating behavior in university hospital's nurses. METHODS: For this assessment, a cross-sectional study was conducted with 300 university hospital's nurses. Nurses were questioned with self-reported questionnaire forms. After excluding cases with incomplete data, 276 cases are enrolled in the study. To find the factors associated with the abnormal eating behavior, we conducted multiple logistic regression analysis. RESULTS: The proportions of shift work nurses were 63.77%(176 cases). The proportions of abnormal eating behavior among shift work nurses were 22.73%(40 cases), but only 6.00%(6 cases) among non-shift work nurses had the abnormal eating behavior. Considering the shift work period, the proportions of abnormal eating behavior were 31.25%, 22.92% and 17.50% in case of shift work period were less than 1 year, 1~3 years and more than 3 years, respectively. The abnormal eating behavior was associated with having shift work, doing exercise, more weekly working hours, being on a diet and having perception of overweight. But age and body mass index were not influenced the abnormal eating behavior. CONCLUSIONS: In this study, we found that the factors associated with the abnormal eating behavior are the shift work, exercise, weekly working hours, perception of overweight and diet.

Appropriateness Ratings in Cataract Surgery

This study aimed to evaluate the appropriateness of cataract surgery and identify the characteristics of patients and surgeons, clinical and functional outcomes, and surgical methods associated with appropriate cataract surgery. For this purpose, Korean cases of cataract surgery were rated as either 'necessity', 'appropriate', 'uncertain' or 'inappropriate', based on RAND/UCLA Ratings. For this assessment, the cases of 222 patients who underwent cataract surgery, on either one or both eyes, were studied. The surgeries were performed by 20 ophthalmologists practicing at one of fourteen medical institutions (university hospitals and general hospitals). Patients were interviewed and clinical data collected. The Doctors were questioned with self-entered questionnaire forms. The medical records were also examined to gain an understanding of the surgical process. The ratings were as follows: 30.6% (68 patients) of surgeries belonged to the bracket "necessity", 46.4% (103 patients) to "appropriate", 15.3% (34 patients) to "uncertain" and 7.7% (17 patients) to "inappropriate". In this study, "necessity" and "appropriate" were defined as "appropriate" (77.0%, 171 patients), and "uncertain" and "inappropriate" as "inappropriate" (23.0%, 51 patients). The low preoperative Snellen visual acuity and visual function, advanced age and male patients were associated with appropriate surgery. It is concluded that appropriate surgery was related to the clinical and functional outcomes (visual acuity and visual function) and patient characteristics (age and male).

Time Series Observations of Outcome Variables and the Factors Associated with the Improvement in the Patient Outcomes of Cataract Surgery / 예방의학회지

OBJECTIVES: To compare the multiple outcomes of patients with cataract surgery at perioperative time, 3-4 months and 12 months after surgery and to assess patient outcomes associated with visual improvement(visual acuity of operated eye, visual function-14(VF-14), symptom score). METHODS: For this assessment, a prospective study was conducted with 389 patients who had undergone cataract surgery for either one eye or both eyes. The surgery was performed by 20 ophthalmologists who were practicing at university hospitals and general hospitals. Patients were interviewed and clinical data were obtained. Doctors were questioned with self-reported questionnaire forms. Medical records were examined in order to measure variables related to the surgical process such as surgical methods and ocular comorbidity. The survey was conducted at 4 stages : preoperative time(389 cases), perioperative time(344 cases, 88.4%), postoperative 3-4 months (343 cases, 88.2%), and postoperative 12 months (281 cases, 72.2%). After excluding cases with incomplete data, 198 cases were enrolled in the study. Patient outcomes was measured for any improvement in the functional outcomes(visual acuity of operated eye, visual function, symptom score) at postoperative 3-4 months. RESULTS: The visual acuity(operated, weighted average), symptom score, VF-14 score, satisfaction with vision, and subjective health status were shown to be improved at the perioperative time, postoperative 3-4 months and 12 months. An improvement in the Snellen visual acuity score was observed in 190 patients(96.0%), whereas improvements of the VF-14 score and cataract symptom score were observed in 151 patients(76.3%) and 179 patients(90.4%), respectively. All three outcome measures demonstrated improvement in 137 patients(69.2%). The improvement of the three functional outcomes at 3-4 months after receiving surgery was associated with a lower level of visual function and a higher level of cataract symptom score at perioperative time, as well as a greater experience level of the surgeon. CONCLUSIONS: In this study, the estimates of the proportion of patients benefiting from cataract surgery varied with the outcome measure of benefit. Preoperative VF-14 score, a measure of functional impairment related to vision, and symptom score may be better measures of the benefit derived from cataract surgery than the change in visual acuity.

Risk Factors of Low Back Pain in a General Population

OBJECTIVE: To examine the correlation between the prevalence and the risk factors of low back pain. METHOD: The number of subjects in this study was 575 men and 325 women who have visited the health center of the CHA hospital. The prevalence of low back pain was evaluated and the risk factors were assessed by history taking, physical examination and the questionnaires. Estimated factors influencing low back pain were age, sex, height, weight, body mass index, waist to hip ratio, range of motion, smoking, alcohol drinking, fitness and other disease. RESULTS: 1) Low back pain was correlated with age, sex, waist to hip ratio, flexibility, arthritis, nervous and depressive disorder and daily activities. 2) Chronic low back pain was correlated with age, right lateral bending, arthritis, cardiovascular disorder and daily activities. 3) Radicular symptom was correlated with age, left and right lateral bending, smoking, exercise, arthritis, nervous and depressive disorder, diabetes and daily activities. 4) Height, weight, body mass index and alcohol drinking had no correlation with low back pain. CONCLUSION: Understanding of the risk factors for low back pain will be helpful for providing objective standards for assessment of low back pain and preventing occurrence and recurrence of low back pain.

The Prevalence of Cancer in Kangwha County / 예방의학회지

OBJECTIVES: Most descriptive studies of cancer have focused either on cancer incidence or mortality. Cancer prevalence has rarely been estimated. Cancer prevalence data can be used as a measure of the economic and social burden of cancer and are also useful for health care planning. This study attempts to estimate cancer prevalence in Kangwha county. METHODS: This investigation is based on data of Kangwha cancer registry. The data include all cases of cancer diagnosed from 1983 through 1992. We define "prevalent cases" as cancer patients who is alive as of January 1, 1993. For each five-year age group, the number of "known prevalent cases" is added to the number of "estimated prevalent cases". Prevalence is calculated by dividing these sums by the populations of Kangwha County on December 31, 1992(derived from Kangwha Statistics Annual). RESULTS: Crude prevalence of cancer among males and females are 536.7 and 601.1 per 100,000 respectively. Gastric cancer is the most common malignant neoplasm(213.2 per 100,000, crude prevalence) among males. It is followed by lung cancer(45.1 per 100,000), liver cancer(32.8 per 100,000), rectal cancer(25.4 per 100,000) and colon cancer(25.4 per 100,000). Cervical cancer is the most common cancer(201.9 per 100,000, crude prevalence) and is followed by gastric cancer(91.5 per 100,000), thyroid cancer(64.8 per 100,000), breast cancer(57.2 per 100,000) and rectal cancer(32.7 per 100,000) among females. CONCLUSIONS: We tried to estimate cancer prevalence based on the Kangwha cancer registry for the first time in Korea. The estimation of cancer prevalence based on a population-based cancer registry will be more correct and useful as the data accumulate. We will make another estimation in the near future.

Survival Analysis of the Children with Down Syndrome / 대한주산의학회잡지

OBJECTIVE: To determine the life expectancy and causes of death of the children with Down syndrome(DS), longitudinal follow-up study was done for 29 cases of DS who were born at CHA hospital located in Seoul During the period from July 1991 to Dec. 1994. METHODS: 29 cases were divided into groups according to the presence of congenital heart disease (CHD) and leukemia. CHD group was subdivided into DS with complete AVSD(atrioventricular septal defect) and DS without complete AVSD. Survival curves were calculated by kaplan-Meier product limit method. Each group were compared by log rank test. The factors affecting mortality rate were analyzed by Cox's proportional hazard regressional model. RESULTS: There were no statistical differences in mortality rate between groups with CHD(35.3%) and without CHD(33.3%)(p=0.7373). Statistical difference was not observed between CHD subgroups with AVSD and with CHD other than AVSD. There were significant statistical difference in mortality rate between groups with leukemia and without leukemia(p=0.0001). CONCLUSION: The factor affecting mortality rate of DS was the presence of leukemia regardless of presence of CHD in our study cases with DS.

Cancer Incidence in Kangwha County(1986 - 1992) / 예방의학회지

OBJECTIVES: This paper presents the information on the incidence of cancer from the population-based cancer resistry in Kangwha County. Material and METHODS: This investigation is based on Kangwha cancer registry. The data included cases of cancer diagnosed from 1986 through 1992. The diagnosis of cancer was confirmed by a team of physicians and nurses with the medical records kept in the clinics and hospitals based on the diagnostic criteria recommended by WHO. Home visitings were also made to cancer patients confirmed in every 6 months for the follow up and for the collection of relevant information directly from the patients. RESULTS: A total of 992 cancer cases were registered during 1986 - 1992. The age-adjusted cancer incidence rate of all site is 201.7 in men and 110.7 in women. The most common cancer is the stomach cancer in both sexes. The age-adjusted incidence rate of the stomach cancer is 65.9 in men and 25.0 in women per 100,000 population. The lung cancer(33.8) and liver cancer(27.7) are next common cancers in men. The cervical cancer(21.8) and lung cancer(8.4) are next in women. CONCLUSION: The most common cancer is the stomach cancer in both sexes. The annual age-adjusted incidence rate of the stomach cancer is 65.9 in men and 25.0 in women per 100,000 population.

A Case-Control Study on Risk Factors of CHD: Vegetable consumption and risk for CHD in Korean men / 한국역학회지

The purpose of this study was to investigate the association of vegetable consumption with the incidence of CHD in Korean men by a case-control study. The case group consisted of 108 patients with EKG-confirmed myocardial infarct or angiographically-confirmed(>or=50% stenosis) angina pectoris admitted to a university teaching hospital in Seoul, Korea. Controls were 142 age-matched patients admitted to the departments of ophthalmology and orthopedic surgery at the same hospital. Dietary intake was assessed by a nutritionist using a semiquantitative food frequency method, while body mass index (BMI), tobacco use, and past history of cardiovascular disease were determined during an interview and examination. The consumption of vegetables was classified by the average frequency of intake(less than 3 times/week, 3~4 times/week, 5~6 times/week, more than once/day). The percentage of subjects who consumed vegetables less than 3 times per week was 29.6% for cases and 17.6% for controls; while men who consumed vegetavle more than once per day were 16.7% for cases and 32.4% for controls. After the adjustment for age, body mass index, and tobacco use, the odds ratio of men who consumed vegetables at least once per day was 0.38(95% confidence interval, 0.18-0.85) compared with men who consumed vegetables less than three times per week. These results suggested that in a population with a relatively low fat intake, consumption of vegetables at least once per day may reduce the risk of CHD in men.

Changes in blood pressure and determinants of blood pressure level and change in Korean adolescents / 예방의학회지

Many studies have led to the notion that essential hypertension in adults is the result of a process that starts early in life: investigation of blood pressure(BP) in children and adolescents can therefore contribute to knowledge of the etiology of the condition. a A unique longitudinal study on BP in Korea, known as Kangwha Children's Blood Pressure(KCBP) Study was initiated in 1986 to investigate changes in BP in children. This study is a part of the KCBP study. The purposes of this study are to show changes in BP and to determine factors affecting to BP level and change in Korean adolescents during age period 12 to 16 years. A total of 710 students(335 males, 375 females) who were in the first grade at junior high school(12 years old) in 1992 in Kangwha County, Korea have been followed to measure BP and related factors(anthropometric, serologic and dietary factors) annually up to 1996. A total of 562 students(242 males, 320 females) completed all five annual examinations. The main results are as follows: 1. For males, mean systolic diastolic BP at age 12 and 16 years old were 108.7 mmHg & 118.1 mmHg(systolic), and 69.5 mmHg & 73.4 mmHg(diastolic), respectively. BP level was the highest when students were at 15 years old. For females, mean systolic and diastolic BP at age 12 and 16 years were 114.4 mmHg & 113.5 mmHg(systolic) and 75.2 mmHg & 72.1 mmHg(diastolic), respectively. BP level reached the highest point when they were 13-14 years old. 2. Anthropometric variables(height, weight and body mass index etc) increased consitantly during the study period for males. However, the rate of increase was decreased for females after age 15 years. Serum total cholesterol decreased and triglyceride increased according to age for males, but they did not show any significant trend for females. Total fat intake increased at age 16 years compared with that at age 14 years. Composition of carbohydrate, protein and fat among total energy intake was 65:15:20 at age 14 and 16 years. 3. Most of anthropometric measures, especially, height, body mass index(BMI) and triceps skinfold thickness, showed a significant correlation with BP level in both sexes. When BMI was adjusted, serum total cholesterol showed a significant negative correlation with systolic BP at age 12 years in males, but at age 14 years the direction of correlation changed to positive. In females serum total cholesterol was negatively correlated with diastolic BP at age 15 and 16 years. Triglyceride and creatine showed positive correlation with systolic and diastolic BP in males, but they did not show any correlation in females. There was no consistent findings between nutrient intake and BP level. However, protein intake correlated positively with diastolic BP level in males. 4. Blood pressure change was positively associated with changes in BMI and serum total cholesterol in both sexes. Change in creatine was associated with BP change positively in males and negatively in females. Students whose sodium intake was high showed higher systolic and diastolic BP in males, and students whose total fat intake was high maintained lower level of BP in females. The major determinants on BP change was BMI in both sexes.

A Study on Tracking by Using Random Coefficient Model / 한국역학회지

There are many epidemiologic studies to find the tracking phenomenon. In repeated measurement data, a population is said to have tracking phenomenon with respect to particular chracteristic if, for each individual, the relative rank of observed value maintained over time. Understanding tracking phenomena in epidemiologic study is quite important. If the risk factors of chronic disease have tracking phenomenon, early detection of these risk factors can lead to the possibility of early treatment. In this study, we defined tracking as relative maintenance and proposed new measure of tracking by using random coefficient model. We compared our measure with McMahan's using simulation study. And we applied ours to real data. We may conclude that our new measure of tracking is adequate in explaining and dectecting the tracking phenomenon.

Four-year change and tracking of serum lipids in Korean adolescents / 예방의학회지

It has been known that there is a tracking phenomenon in the level of serum lipids. However, no study has been performed to examine the change and tracking of serum lipids in Korean adolescents. The purpose of this study is to examine the changes of serum lipids in Korean adolescents from 12 to 16 years of age, and to examine whether or not there is a tracking phenomenon in serum lipids level during the period. In 1992 serum lipids(total cholesterol(TC), triglyceride(TG), LDL cholesterol(LDL-C), HDL cholesterol(HDL-C)) were measured in 318 males, 365 females who were 12 years of age in Kangwha county, Korea. These participants have been followed up to 1996 and serum lipids level were examined in 1994 and 1996. Among the participants 162 males and 147 females completed all three examinations in fasting state. To examine the effect of eliminating adolescents with incomplete data, we compared serum lipids, blood pressure and anthropometric measures at baseline between adolescents with complete follow-up and adolescents who were withdrawn. To examine the change of serum lipids we compared mean values of serum lipids according to age in males and females. Repeated analysis of variance was used to test the change according to age. We used three methods to examine the existence of tracking. First, we analyzed the trends in serum lipids over 4-year period within quartile groups formed on the basis of the first-year serum lipids level to see whether or not the relative ranking of the mean serum lipids among the quartile groups remained in the same group for 4-year period. Second, we quantified the degree of tracking by calculating Spearman's rank correlation coefficient between every tests. Third, the persistence extreme quartile method was used. This method divides the population into quartile groups according to the initial level of blood lipids and then calculates the percent of the subjects who stayed in the same group at follow-up measurement. The decreases in levels were noted during 4 years for TC, LDL-C, primarily for boys. The level of HDL-C decreased between baseline and first follow-up for both sexes and girls. Tracking, as measured by both correlation coefficients and persistence extreme quartiles, was evident for all of the lipids. The correlation coefficients of TC between baseline and 4 years later in boys and girls were 0.55 and 0.68, respectively. And the corresponding values for HDL-C were 0.58 and 0.69. More than 50% of adolescents who belonged to the highest quartile group in TC, HDL-C and LDL-C at the baseline were remained at the same group at the examination performed 2 years later for both sexes. The probability of remaining at the same group was more than 35% when examined 4 years later. The tracking phenomenon of TG was less evident compared with the other lipids. Percents of girls who stayed at the same group 2 years later and 4 years later were 42.9% and 25.7%, respectively. It was evident that serum lipid levels tracked in Korean adolescents. Researches with longer follow-up would be needed in he future to investigate the long-term change of lipids from adolescents to adults.

A Study on Misclassification Arising from Random Error in Exposure Measurement / 한국역학회지

There are many epidemiologic studies to find the relationship between disease occurrence and categorized exposure variables which are measured in continuous scales. Recently, it has been found that the differential misclassification can arise when exposure variables are observed with measurement errors and categorized for the analysis. Even though the differential misclassification leads to serious misclassification bias, there is no theoretical attempt to correct the misclassification bias occuring in these circumstances. In this paper, we propose a new statistical method to reduce the misclassification bias due to dichotomizing continuous exposure variables. Since the exposure values are more likely to be misclassified when the true exposure values are close to the cutoff point, the method proposed here gives smaller weights in these case and more weights when these values are far from cutoff point. Simulation studies are performed to compare the bias and the power of the proposed method compared to other methods. Main results are as follows: 1. The proposed method produces the smaller bias and the higher power than the simple method which modifies misclassified data using sensitivity and specificity of exposure misclassification. 2. When the standard deviation of the measurement error are moderately large, the bias and the power of the proposed estimate are somewhat better than those of the modified estimate which excluding the misclassified observations in the analysis. In conclusion, the method proposed here is found to be useful in epidemiologic studies when continuous exposure variables are obtained with measurement error and categorized in the analysis.

Cross-specialty linkage and extrapolation of resource-based relative value scales

This article describes methods used to produce a RBRVS (resource-based relative value scales), a common scale from two specialties (internal medicine and general surgery) and explains the newly developed extrapolation process within each specialty. To produce a common scale, we selected six 'same' services as linking services common to both specialties. Then we used the bi-weighted least squares method to locate all the same services on a single, common scale. By using the same method, we tried to extrapolate all the services within each specialty, not by the method of Kelly et al, dividing all the services within the specialty into families (small homogeneous groups of services) to apply charge-based ratios. To compare both methods, we extrapolated all the services of general surgery according to each method. With the correlation analysis to compare both results to American RVUs, we found that general surgery's RVUs from our own extrapolation method turned out to be more highly correlated with American RVUs than from Kelly's extrapolation method. Consequently, extrapolation with bi-weighted least squares method gave reasonable results.

Comparison of work measures for some physician services in Obstetrics & Gynecology / 예방의학회지

We have never seen any method to cope basically with complicated situation and problems around medical reimbursement rates here in Korea since 1977 witnessed by the beginning of medical insurance. By the way researchers concerned are beginning to propose some kinds of innovative and detailed ideas to government these days. They are Diagnosis-related group(DRG)and Resource-based relative value scale(RBRVS). In the light of this situation it is so encouraging that our government can come up with that and move. In case of RBRVS research we have already been reaching even to the level of reviewing and revising methodology for its further development after naive pilot study on internal medicine and general surgery last year. However there might be something different conditions between USA and Korea to apply the same Dr. Hsiao's method and it must be vital to check so called 'total work approach' compared with 'intra-service work approach' before expanding to the whole medical fields. According to the 'Intra-service approach', the physician's work is supposed to be divided into three sub-works by the name of intraservice work, pre, and post service work. These sub-works, again should be merged together to be the pre-postwork subset through some statistical methods of the estimation process applied by Dr. Hsiao's methodology in RBRVS development later on. But in this paper that estimation process was not taken because we could have real values for all of those surveyed items related to just one specialty, OB & GY. Instead, we used some statistical comparison procedures relevant to demographic characteristics, reliability & validity and correlation analysis with American RVU(Relative value unit) between the total work and merged total work from intraservice work approach. The unit of analysis was individual physicians of OB & GY and 300 physicians were selected for each approach through statistical sampling method based on national population of OB & GY physicians in korea. And also with the thankful help of Advisory committee under Korean Association of OB & GY, questionnaires were made and mailed to the subjects, two times. As a result there were not any statistically significant differences in demographic characteristics between the two approaches except for the variable 'Response time for the questionnaire', but in other sections of comparisons, response rate, representative values, reliability & validity test, correlation analysis with American RVU, all showed 'Total approach' was not only more rational and statistically meaningful than ,'Intra-service approach' but also had considerable merits. But we are not absolutely sure about this paper's robustness. Because of some limitations, we'd rather like to suggest further researches should be followed. In that sense the first thing would be a research for the influence of doctor's haracteristics, especially 'frequency' on the rating of work and the way to define total work more clearly.

A methodological study on simplifying claims review system in medical insurance / 예방의학회지

After the introduction of National Medical Insurance in 1989, the medical demand has rapidly increased. The impact of increased medical demand was followed by an increase in the number of claims in need of review. We studied a new, fair method for reducing the number of claims reviewed. we analysed 90,583 outpatient claims submitted between september and october; claims were made for services given August of 1994. We finally suggested a screening system for claims review using a statistical method of discriminant analysis of the medical costs. The results were as follows. 1. In the cut-off group, age, days of medication, number of hospital or clinic visits, and total change were significantly high The cut-off rates according to the hospital-type and existence of accompanied disease were significantly different. 2. According to ICD, the cut-off rate was highest in peripheral enthesopathies and allied syndromes(20.76%), lowest in acute sinusitis(0.93%). The mean charges were significantly different according to ICD and existence of cut-off. 3. we build discriminant functions by ICD with such discriminant variables as patient age, sex, existence of accompanied disease, number of hospital or clinic visits, and 9 detailed hospital or clinic charges included in claim. 4. we applied the discriminant function for screening those claims that were expected to be cut-off. The sensitivities comprised from 40% to 70%, and specificities from 70% to 95% by ICD. Acute rhinitis had highest sensitivity(100.00%)and other local infections of skin and subcutaneous tissue had highest specificity(98.45%). The excepted number of cut-off was 17,762(19.61%). The total sensitivity was 49.62%, the total specificity was 82.57% and the error rate was 19.66%. We lacked economic analysis such as cost-benefit analysis. But, if the few method of screening claims using discriminant analysis were applied, the number of claims in need of review will reduce considerably.