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.
Bias (Epidemiology) ; Sensitivity and Specificity ; Weights and Measures

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.
Diagnosis ; Female ; Follow-Up Studies ; House Calls ; Humans ; Incidence* ; Liver ; Lung ; Male ; Medical Records ; Stomach Neoplasms

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).
Aged ; Cataract Extraction/*standards/*utilization ; Female ; Human ; Male ; Middle Aged ; *Outcome Assessment (Health Care) ; Patient Satisfaction ; Questionnaires ; Unnecessary Procedures ; Visual Acuity

The coexistence of extraadrenal pheochromocytoma and renal artery stenosis is extremely rare. The mechanisms of renal artery stenosis with pheochromocytoma include direct compression of the tumor mass on the renal artery and catecholamine-induced vasospasm, fibromuscular hyperplasia, and fibrous adhesion. We report a rare case of renal artery stenosis caused by extraadrenal pheochromocytoma in a 29- year-old female. She was admitted to the hospital because of palpitation and headache. She had been treated for hypertension for 2 years. On admission, her plasma epinephrine and norepinephrine levels were elevated as were her plasma renin activity, urinary vanillylmandelic acid (VMA) and metanephrine levels. Through the use of abdominal computed tomography, 131I-MIBG scan, and renal arteriography, a mass was found in the hilus of the left kidney which affected left renal artery stenosis. Surgical removal of the mass and left kidney restored the catecholamine excretion, plasma renin activity, and blood pressure to normal. Electronmicroscopic examination of the mass confirmed the pheochromocytoma.
Angiography ; Blood Pressure ; Epinephrine ; Female ; Headache ; Humans ; Hyperplasia ; Hypertension ; Kidney ; Metanephrine ; Norepinephrine ; Pheochromocytoma* ; Plasma ; Renal Artery Obstruction* ; Renal Artery* ; Renin ; Vanilmandelic Acid

BACKGROUND: For Neer type IIB fracture of distal clavicle with coracoclavicular ligament injury, various surgical treatments have been used in literatures. However, there was no consensus on the optimal treatment. The aim of this study is to report the clinical and radiological results of open reduction and internal fixation of unstable distal clavicle fracture and suture augmentation of disrupted coracoclavicular ligament. METHODS: A prospective study was performed in 23 patients with Neer type IIB distal clavicle fracture in Seoul Medical Center, Eulji Hospital, and National Medical Center. Firstly, suture anchors are inserted in the base of coracoid process and preliminary reduction was achieved by tie-off of three suture limbs around the clavicle. Then, the final fixation was completed with anatomical locking plate. Bony union and the distance between coracoclavicular ligaments were evaluated. Clinical results and complications including stiffness and secondary procedures were evaluated. RESULTS: Bony union was achieved in all cases except one (22 of 23). At mean 14.9 months, no significant difference in the mean coracoclavicular distance was observed compared to uninjured shoulder (8.2 +/- 7.9 mm versus 7.3 +/- 3.4 mm, p=0.14). Pain visual analogue scale, American Shoulder and Elbow Surgeons score, Constant score, and Disabilities of the Arm, Shoulder and Hand score were 0.5, 83.4, 78.5, and 6.2, respectively. Revision surgery was performed in one case of nonunion. Four patients who complained of skin irritation underwent implant removal. CONCLUSIONS: In cases of an unstable distal clavicle fracture with coracoclavicular ligament disruption, satisfactory clinical results were obtained by locking plate fixation and coracoclavicular ligament suture augmentation concurrently.
Arm ; Clavicle* ; Consensus ; Elbow ; Extremities ; Hand ; Humans ; Ligaments* ; Prospective Studies ; Seoul ; Shoulder ; Shoulder Fractures ; Skin ; Suture Anchors ; Sutures*

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.
Body Mass Index ; Cross-Sectional Studies ; Diet ; Eating* ; Feeding Behavior* ; Logistic Models ; Overweight ; Surveys and Questionnaires

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.
Chronic Disease ; Risk Factors

Foreign bodies in upper digestive tract are one of frequently encountered accidental cases in otolaryngologic fields. Esophageal hematoma have been reported in association with impaired hemostasis, emetogenic, food-related injury, and spontaneous disorder. Submucosal hematoma of the esophagus caused by food-related traumatic injury is a rare entity. A study has reported that various foods, such as fish bones, hot noodles, steak, spice, and hard confections cause esophageal injury, resulting in esophageal submucosal hematoma. Hematoma occurs within the submucosal plane of the esophagus, causing dissection of mucosa from its underlying muscle, resulting in extramucosal narrowing of the esophageal lumen. Its prognosis is good, and improvement is achieved by conservative treatment. We experienced an uncommon esophageal submucosal hematoma caused by an esophageal fish bone. Therefore, we report this case with a review of literature.
Candy ; Esophagus ; Foreign Bodies* ; Gastrointestinal Tract ; Hematoma* ; Hemostasis ; Mucous Membrane ; Prognosis ; Spices

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.
Aneurysm ; Humans ; Intracranial Aneurysm ; Retrospective Studies

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.
Breast ; Colon ; Delivery of Health Care ; Female ; Humans ; Incidence ; Korea ; Liver ; Lung ; Male ; Mortality ; Prevalence* ; Stomach Neoplasms ; Thyroid Gland ; Uterine Cervical Neoplasms