• Journal of Nutrition and Health
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• 제33권8호
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• pp.864-872
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• 2000

This study intended to evaluate the validity of the simple nutrition screening test that had been developed with the elderly living in Cheongju as a subject. Nutrition screening score(NSS) and reference standards for nutritional and health status(nutrient intakes, mean adequacy ratio, perceive health, and serum albumin, hematocrit, and hemoglobin) were estimated by using the date obtained in 1996 from the 174 elderly living in Taejon, Statistical analysis showed significant correlations between mean adequacy ratio(MAR) and NSS(r=0.341) and also between NSS and biological indices such as albumin and hematocrit, Around 65-75% of the elderly with perceive health and low level of serum albumin, hemoglobin and hematocrit had NSS$\leq$ll. Sensitivity, specificity, and positive predictive values(PPV) were calculated from the crosstabulation of the three categories of NSS(high, moderate, and low nutritional risk) and low categories MAR(< 0.75, undernutrition;$\geq$0.75, normal) to validate the cut-off point for high or low nutritional risk by NSS. It was suggested that point l1 was appropriate as a criterion to determine high risk of undernutrition, but point 16 was better than 17 as criterion to determine low nutritional risk in the Taejon elderly. When point ll was used as a criterion of high nutritional risk, sensitivity, specificity, and PPV are 59.5, 60.5 and 82.1 respectively. When point 16 was used as a criterion of low nutritional risk, sensitivity, specificity, and PPV are 25.6, 95.4, and 64.7%, respectively. In conclusion, nutrition screening test that had been developed can be a simple, easy, and proper instrument to classify the high risk group of undernutrition. A further validation study seems to be required among other groups of individuals for the screening test to the finalized as a more valid instrument identifying Korean elderly at nutrition and health risk(Korean J Nutrition 33(8) : 864-872, 2000)

• Journal of Preventive Medicine and Public Health
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• 제22권1호
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• pp.45-50
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• 1989

The purpose of this study was to select the manageable diseases which are prevalent in Korea for periodic health examinations and to evaluate the sensitivity and specificity of periodic health examination in detecting these diseases. The data was derived from reimbursement data of the Korea Medical Insurance Corporation over a two year period (April 15, 1986 to April 14,1988) and interviews with Yonsei Medical School professors. This study demonstrated that: 1. The manageable diseases which were selected for periodic health examinations are pulmonary tuberculosis, viral hepatitis, diabetes mellitus, syphilis groups, essential hypertension, renal disease groups, and iron deficiency anemia. 2. The sensitivity of the health screening for each disease was as follows: pulmonary tuberculosis 51.5%, viral hepatitis 60.3%, diabetes mellitus 64.7%, syphilis groups 63.3%, essential hypertension 49.9%, renal disease groups 44.0%, and iron deficiency anemia 80.9%. We conclude that peiodic health esaminations should focus on the manageable diseases that we have defined. The number of items in periodic health screening tests and hospital quality control should be increased for the diseases with a demonstrated low sensitivity.

• Korean Journal of Radiology
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• 제24권2호
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• pp.155-165
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• 2023

Objective: Little is known about the effects of using different expert-determined reference standards when evaluating the performance of deep learning-based automatic detection (DLAD) models and their added value to radiologists. We assessed the concordance of expert-determined standards with a clinical gold standard (herein, pathological confirmation) and the effects of different expert-determined reference standards on the estimates of radiologists' diagnostic performance to detect malignant pulmonary nodules on chest radiographs with and without the assistance of a DLAD model. Materials and Methods: This study included chest radiographs from 50 patients with pathologically proven lung cancer and 50 controls. Five expert-determined standards were constructed using the interpretations of 10 experts: individual judgment by the most experienced expert, majority vote, consensus judgments of two and three experts, and a latent class analysis (LCA) model. In separate reader tests, additional 10 radiologists independently interpreted the radiographs and then assisted with the DLAD model. Their diagnostic performance was estimated using the clinical gold standard and various expert-determined standards as the reference standard, and the results were compared using the t test with Bonferroni correction. Results: The LCA model (sensitivity, 72.6%; specificity, 100%) was most similar to the clinical gold standard. When expert-determined standards were used, the sensitivities of radiologists and DLAD model alone were overestimated, and their specificities were underestimated (all p-values < 0.05). DLAD assistance diminished the overestimation of sensitivity but exaggerated the underestimation of specificity (all p-values < 0.001). The DLAD model improved sensitivity and specificity to a greater extent when using the clinical gold standard than when using the expert-determined standards (all p-values < 0.001), except for sensitivity with the LCA model (p = 0.094). Conclusion: The LCA model was most similar to the clinical gold standard for malignant pulmonary nodule detection on chest radiographs. Expert-determined standards caused bias in measuring the diagnostic performance of the artificial intelligence model.

• 대한임상검사과학회지
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• 제45권1호
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• pp.26-31
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• 2013

The cytology of sputum specimens, at a medical facility in Korea, is using the liquid-based cytology and conventional smear method. It confirms the diagnosis using conventional smear methods and the liquid-based cytology. In addition, the diagnosis uses two kinds of each method, compares the suitability, sensitivity and specificity for each test and tries to understand the efficient method needed. It divided sputum specimens in half and liquid-based cytology. A conventional smear method was conducted and the Papanicolaou's staining was conducted using Autostainer. Diagnosed each slide of staining produced smear slides specimens by using an optical microscope. The result of the liquid-based cytology and conventional smear method was that the liquid-based cytology was of a higher-grade than the conventional smear method. It was 36.8%, and 62.8% in the same condition. But only one case was of a lower grade. Liquid-based cytology showed 86.2% of adequacy, 31.0% of sensitivity and 97.5% of specificity. The conventional smear method showed 54.4% of adequacy, 19.6% of sensitivity and 100% of specificity. If it was conducted with two methods at the same time, the results would be similar to the liquid-based cytology. In conclusion, liquid-based cytology has a more superior adequacy and sensitivity than the conventional smear method. The combination of the two methods is similar to the result of only conducting a liquid-based cytology. Conducting a liquid-based cytology rather than the combination of the two ways of sputum cytoscopy, is to be considered as an efficient method to achieve diagnostic accuracy, reduce labor of clinical technologist and pathologist, and to reduce the expense of patients.

• Annals of Laboratory Medicine
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• 제39권1호
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• pp.50-57
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• 2019

Background: The Automated Fluorescent Immunoassay System (AFIAS) rotavirus assay (Boditech Med Inc., Chuncheon, Korea) is a new rapid antigen test for rotavirus detection. We evaluated the performance of this assay for detecting rotaviruses and their specific genotypes in clinical stool samples. Methods: AFIAS rotavirus assay was performed in 103 rotavirus-positive and 103 rotavirus-negative stool samples (confirmed by both PCR and ELISA), and its results were compared with those of PCR, ELISA, and immunochromatographic assay (ICA). We evaluated diagnostic sensitivity/specificity, the detectability of rotavirus subtypes, lower limit of detection (LLOD), reproducibility, cross-reactivity, and interference of AFIAS rotavirus assay. Results: Based on PCR and ELISA results, diagnostic sensitivity and specificity of the AFIAS rotavirus assay were both 99.0%. LLOD results showed that the AFIAS assay had sensitivity similar to or greater than ICA and ELISA. High reproducibility was confirmed, and no cross-reactivity or interference was detected. This assay could detect genotypes G1P[8], G2P[4], G3P[8], G4P[6], G4P[8], G8P[4], G8P[8], G9P[4], and G9P[8]. Conclusions: The AFIAS rotavirus assay showed high reproducibility, sensitivity, and specificity as well as excellent agreement with ELISA, PCR, and ICA. It detected the most common as well as unusual genotypes of rotavirus prevalent in Korea. It could be a useful onsite assay for rapid, convenient, and cost-effective detection of rotavirus infection.

• Tuberculosis and Respiratory Diseases
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• 제84권3호
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• pp.226-236
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• 2021

Background: Although the Quidel Sofia rapid influenza fluorescent immunoassay (FIA) is widely used to identify influenza A and B, the diagnostic accuracy of this test remains unclear. Thus, the objective of this study was to determine the diagnostic performance of this test compared to reverse transcriptase-polymerase chain reaction. Methods: A systematic literature search was performed using MEDLINE, EMBASE, and the Cochrane Central Register. Pooled sensitivity, specificity, diagnostic odds ratio (DOR), and a hierarchical summary receiver-operating characteristic curve (HSROC) of this test for identifying influenza A and B were determined using meta-analysis. A sensitivity subgroup analysis was performed to identify potential sources of heterogeneity within selected studies. Results: We identified 17 studies involving 8,334 patients. Pooled sensitivity, specificity, and DOR of the Quidel Sofia rapid influenza FIA for identifying influenza A were 0.78 (95% confidence interval [CI], 0.71-0.83), 0.99 (95% CI, 0.98-0.99), and 251.26 (95% CI, 139.39-452.89), respectively. Pooled sensitivity, specificity, and DOR of this test for identifying influenza B were 0.72 (95% CI, 0.60-0.82), 0.98 (95% CI, 0.96-0.99), and 140.20 (95% CI, 55.92-351.54), respectively. The area under the HSROC for this test for identifying influenza A was similar to that for identifying influenza B. Age was considered a probable source of heterogeneity. Conclusion: Pooled sensitivities of the Quidel Sofia rapid influenza FIA for identifying influenza A and B did not quite meet the target level (≥80%). Thus, caution is needed when interpreting data of this study due to substantial betweenstudy heterogeneity.

• Clinical and Experimental Pediatrics
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• 제60권7호
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• pp.208-215
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• 2017

Purpose: Activation of Toll-like receptor 2 (TLR2) present on circulating monocytes in patients with Kawasaki disease (KD) can lead to the production of proinflammatory cytokines and interleukin-10 (IL-10). We aimed to determine the association of the frequency of circulating TLR2+/ CD14+ monocytes (FTLR2%) with the outcomes of KD, as well as to compare FTLR2% to the usefulness of sIL-10. Methods: The FTLR2% in patients with KD was measured by flow cytometry. Serum levels of IL-10 (sIL-10) were determined in 31 patients with KD before the initial treatment with intravenous immunoglobulin (IVIG) and in 21 febrile controls by using enzyme-linked immunosorbent assay. Patients were classified as having coronary artery lesions (CALs) based on the maximal internal diameters of the proximal right coronary artery and proximal left anterior descending coronary artery one month after the initial diagnosis. Results: We found that FTLR2% greater than 92.62% predicted CALs with 80% sensitivity and 68.4% specificity, whereas FTLR2% more than 94.61% predicted IVIG resistance with 66.7% sensitivity and 71.4% specificity. Moreover, sIL-10 more than 15.52 pg/mL predicted CALs and IVIG resistance with 40% and 66.7% sensitivity, respectively, and 73.7% and 76.2% specificity, respectively. Conclusion: We showed that measuring FTLR2% before the initial treatment could be useful in predicting CAL development with better sensitivity than sIL-10 and with results comparable to sIL-10 results for the prediction of IVIG resistance in patients with KD. However, further studies are necessary to validate FTLR2% as a marker of prognosis and severity of KD.

• 대한핵의학회지
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• 제31권1호
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• pp.50-56
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• 1997

관상 동맥 질환에서 심근 혈류의 평가를 위하여 사용되는 심근 관류 SPECT는 여성에서의 유방이나 횡격막 감쇠 등 인공 산물에 의하여 위양성으로 나타날 수 있다. 이 연구에서는 게이트 SPECT를 이용하여 관류 SPECT에 나타나는 의심스러운 관류 감소 부위의 벽 운동을 평가하여 관류 감소 부위가 인공 산물인지 판정하였다. 판정 결과는 관상 동맥 조영술 결과와 비교하였다. 대상 환자 275명에서 관류 SPECT의 예민도와 특이도는 각각 87%와 55%였고 게이트 SPECT를 진단에 이용하였을 때 관류 SPECT에서 위양성을 보인 5례의 벽운동이 정상임이 확인되어 특이도가 66%로 향상되었다. 이상의 결과로 게이트 SPECT는 관상 동맥 질환의 특이도를 높이는 데 이용될 수 있을 것으로 생각한다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권16호
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• pp.6881-6885
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• 2014

Background: The present study aimed to investigate the utility and importance of the various parameters of complete blood count panel for benign-malignant differentiation of adnexal masses. Materials and Methods: This retrospective study involved 316 patients with documented benign and 253 patients with malignant adnexal masses who underwent primary surgical treatment at a tertiary referral center. Prior to the study, all benign and malignant cases were compared within their own groups and then the benign and malignant cases were compared to each other. For all cases, cut-off, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for the neutrophil lymphocyte ratio (NLR), platelet lymphocyte ratio (PLR), neutrophil, lymphocyte, platelet and CA-125 parameters, and the results were compared in regards to the groups. Results: NLR, PLR, neutrophil, CA-125, and platelet values were higher in the malignant compared to the benign cases (p<0.01). The lymphocyte value was lower in the malignant cases (p<0.01). No significant differences were found for basophils and eosinophils (p > 0.05). For CA-125, the sensitivity, specificity, PPV and NPV for all cases were 78%, 62%, 62% and 78%, respectively. For NLR, they were 65.6%, 72.1%, 65.3%, and 72.3%, and for PLR, 48%, 81%, 67%, and 66%. Additionally, the sensitivity and specificity were 55% and 77% for CA-125, 66% and 58% for NLR, and 61% and 58% for PLR in early malignant cases. Conclusions: NLR and PLR appear to be useful methods that can be applied together with CA-125 due to the relatively high sensitivity values for the malign-benign differentiation of ovarian masses. Although the specificity of these parameters is lower than CA-125, especially in cases with early malignant ovarian pathology, their sensitivity being higher is promising for the early diagnosis of ovarian cancer. It can be used to detect ovarian malignancies in the early stages, and it will increase the treatment options and improve survival rates.

• 지능정보연구
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• 제19권2호
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• pp.125-140
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• 2013

어떤 클래스에 속한 레코드의 개수가 다른 클래스들에 속한 레코드의 개수보다 매우 많은 경우에, 이 데이터 집합을 '불균형 데이터 집합'이라고 한다. 데이터 분류에 사용되는 많은 기법들은 이러한 불균형 데이터에 대해서 저조한 성능을 보인다. 어떤 기법의 성능을 평가할 때에 적중률뿐만 아니라, 민감도와 특이도도 함께 측정하여야 한다. 고객의 이탈을 예측하는 문제에서 '유지' 레코드가 다수 클래스를 차지하고, '이탈' 레코드는 소수 클래스를 차지한다. 민감도는 실제로 '유지'인 레코드를 '유지'로 예측하는 비율이고, 특이도는 실제로 '이탈'인 레코드를 '이탈'로 예측하는 비율이다. 많은 데이터 마이닝 기법들이 불균형 데이터에 대해서 저조한 성능을 보이는 것은 바로 소수 클래스의 적중률인 특이도가 낮기 때문이다. 불균형 데이터 집합에 대처하는 과거 연구 중에는 소수 클래스를 Oversampling하여 균형 데이터 집합을 생성한 후에 데이터 마이닝 기법을 적용한 연구들이 있다. 이렇게 균형 데이터 집합을 생성하여 예측을 수행하면, 특이도는 다소 향상시킬 수 있으나 그 대신 민감도가 하락하게 된다. 본 연구에서는 민감도는 유지하면서 특이도를 향상시키는 모델을 개발하였다. 개발된 모델은 Support Vector Machine (SVM), 인공신경망(ANN) 그리고 의사결정나무 기법 등으로 구성된 하이브리드 모델로서, Hybrid SVM Model이라고 명명하였다. 구축과정 및 예측과정은 다음과 같다. 원래의 불균형 데이터 집합으로 SVM_I Model과 ANN_I Model을 구축한다. 불균형 데이터 집합으로부터 Oversampling을 하여 균형 데이터 집합을 생성하고, 이것으로 SVM_B Model을 구축한다. SVM_I Model은 민감도에서 우수하고, SVM_B Model은 특이도에서 우수하다. 입력 레코드에 대해서 SVM_I와 SVM_B가 동일한 예측치를 도출하면 그것을 최종 해로 결정한다. SVM_I와 SVM_B가 상이한 예측치를 도출한 레코드에 대해서는 ANN과 의사결정나무의 도움으로 판별 과정을 거쳐서 최종 해를 결정한다. 상이한 예측치를 도출한 레코드에 대해서는, ANN_I의 출력값을 입력속성으로, 실제 이탈 여부를 목표 속성으로 설정하여 의사결정나무 모델을 구축한다. 그 결과 다음과 같은 2개의 판별규칙을 얻었다. 'IF ANN_I output value < 0.285, THEN Final Solution = Retention' 그리고 'IF ANN_I output value ${\geq}0.285$, THEN Final Solution = Churn'이다. 제시되어 있는 규칙의 Threshold 값인 0.285는 본 연구에서 사용한 데이터에 최적화되어 도출된 값이다. 본 연구에서 제시하는 것은 Hybrid SVM Model의 구조이지 특정한 Threshold 값이 아니기 때문에 이 Threshold 값은 대상 데이터에 따라서 얼마든지 변할 수 있다. Hybrid SVM Model의 성능을 UCI Machine Learning Repository에서 제공하는 Churn 데이터 집합을 사용하여 평가하였다. Hybrid SVM Model의 적중률은 91.08%로서 SVM_I Model이나 SVM_B Model의 적중률보다 높았다. Hybrid SVM Model의 민감도는 95.02%이었고, 특이도는 69.24%이었다. SVM_I Model의 민감도는 94.65%이었고, SVM_B Model의 특이도는 67.00%이었다. 그러므로 본 연구에서 개발한 Hybrid SVM Model이 SVM_I Model의 민감도 수준은 유지하면서 SVM_B Model의 특이도보다는 향상된 성능을 보였다.