PURPOSE: The study analyzed and categorized the colorectal cancers related medical journals published in Korea by the name of the journal, research materials, study method, statistical method and by content of study for the quality improvement of colorectal cancers related studies. METHODS: The authors reviewed a total of 567 colorectal cancer-related studies published in the Korean medical journals during the period 1967 and 2004 and kept in the National Assembly Library. The distribution of research materials, study method, statistical method and content of these studies were analyzed by the 5 year publication interval. RESULTS: By study period, the number of published studies steeply increase during the period between 2000 and 2004. As the research materials, hospital patients(64.6%) and In-vitro(16.6%) were the most prevalently used research materials, but health adults were the lowest research materials by only taking up 0.4%. In study methods, patient follow up studies(28.7%) and human in vitro experimental(27.9%) were prevalent, and human in vitro experimental were relatively the most popular performed studies during the years of 1990-1994. As the statistical method, life table and survival analysis(27.0%) were the mostly performed methods, and the use of statistical method was applied in nearly all studies. The contents of the studies mainly focused on the patient prognostic estimations(27.6%) of therapeutic safety & efficacy(25.6%), but only the 4.1% of risk factors studies. Among the 109 studies which analyzed the survival term 78.9% of the studies mainly used the 5 year term in the analysis of survival rates. CONCLUSION: The results of the study could be utilized as the basic data for the quality improvement of further colorectal cancers related studies.
Adult ; Colorectal Neoplasms* ; Follow-Up Studies ; Humans ; Korea ; Life Tables ; Publications ; Quality Improvement ; Research Design ; Risk Factors ; Survival Rate

OBJECTIVES: N100 amplitude slope(the intensity dependence of the cortical auditory evoked potentials) is widely considered as an indirect indicator of central serotonergic neurotransmission. However, there are only a few studies about N100 amplitude slopes of major psychiatric disorders. In this study, we examined N100 amplitude slope differences among major depressive disorder(MDD), bipolar disorder(BD), schizophrenia (SCZ) and normal controls(NC). METHODS: We measured the N100 amplitude slopes of 35 patients with MDD, 33 patients with BD, 27 patients with SCZ and 35 NC subjects. Amplitude differences from N1 to P2 at the five different sound intensities(55, 65, 75, 85 and 95dB) were examined at Cz electrode. The N100 amplitude slope was calculated as the linear regression of five N1/P2 peak-to-peak amplitudes across stimulus intensities. RESULTS: BD patients showed significantly reduced N100 amplitude slope compared with NC(0.54+/-0.70 vs. 0.96+/-0.72, p=0.035). N100 amplitude slope of SCZ patients was significantly reduced compared with NC(0.50 +/-0.47 vs. 0.96+/-0.72, p=0.027). N100 amplitude slope of BD patients was significantly lower than that of MDD patients(0.54+/-0.70 vs. 0.94+/-0.60, p=0.046). SCZ patients also showed significant reduction of N100 amplitude slope compared with MDD patients(0.50+/-0.47 vs. 0.94+/-0.60, p=0.036). There was no significant difference of N100 amplitude slope between MDD patients and NC(0.94+/-0.60 vs. 0.96+/-0.72, p=1.000). CONCLUSION: Interestingly, the N100 amplitude slopes of BD and SCZ were reduced compared to NC and MDD patients. Our results suggest the predictive use of N100 amplitude slope in making differential diagnoses of major psychiatric disorders. Clinical implications of N100 amplitude slope in major psychiatric disorders were discussed.
Bipolar Disorder ; Depressive Disorder, Major ; Diagnosis, Differential ; Electrodes ; Humans ; Linear Models ; Schizophrenia ; Synaptic Transmission