• Title/Summary/Keyword: Sensitivity and specificity

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Reliability of Stool Antigen Tests: Investigation of the Diagnostic Value of a New Immunochromatographic Helicobacter pylori Approach in Dyspeptic Patients

  • Korkmaz, Huseyin;Findik, Duygu;Ugurluoglu, Ceyha;Terzi, Yuksel
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.2
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    • pp.657-660
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    • 2015
  • Background: A diagnosis of H. pylori infection can be made by invasive or non-invasive methods. Several noninvasive diagnostic tests based on the detection of H. pylori stool antigen (HpSA) have been developed. The Genx H. pylori stool antigen card test is a new rapid, non-invasive test that is based on monoclonal immunochromatographic assay. The aim of this study was to determine its sensitivity, specificity, and diagnostic accuracy for diagnosing H. pylori infection in adult patients. Materials and Methods: A total of 162 patients were included in the study. A gastric biopsy was collected for histopathology and rapid urease testing. Stool specimens for HpSA testing were also collected. Patients were considered H. pylori positive if two invasive tests (histological and rapid urease tests) were positive. Results: Using the reference test, 50.6% of the samples were positive for H. pylori infection. The Genx H. pylori antigen test was positive in 19.7% of patients. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of the Genx H. pylori antigen test were 51.6%, 96.0%, 88.8%, 76.1%, and 79.0%, respectively. Conclusions: The Genx H. pylori stool antigen card test is a new non-invasive method that is fast and simple to perform but provides less reliable results.

Reliability and Accuracy of Infrared Temperature: A Systematic Review (적외선 체온의 진단 정확도 평가 연구: 체계적 문헌고찰)

  • Park, Seong-Hi
    • Korean Journal of Adult Nursing
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    • v.26 no.6
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    • pp.668-680
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    • 2014
  • Purpose: The aim of this study was to investigate the accuracy of infrared temperature measurements compared to axillary temperature in order to detect fever in patients. Methods: Studies published between 1946 and 2012 from periodicals indexed in Ovid Medline, Embase, CINAHL, Cochrane, KoreaMed, NDSL, KERIS and other databases were selected using the following key words: "infrared thermometer". QUADAS-II was utilized to assess the internal validity of the diagnostic studies. Selected studies were analyzed through a meta-analysis using MetaDisc 1.4. Results: Twenty-one diagnostic studies with high methodological quality were included representing 3,623 subjects in total. Results of the meta-analysis showed that the pooled sensitivity, specificity, and area under the curve (AUC) of infrared tympanic thermometers were 0.73 (95% CI 0.70~0.75), 0.92 (95% CI 0.91~0.92), and 0.90, respectively. For axillary temperature readings, the pooled sensitivity was 0.67 (95% CI 0.62~0.73), the pooled specificity was 0.87 (95% CI 0.85~0.90), and the AUC was 0.80. Conclusion: Infrared tympanic temperature can predict axillary temperature in normothermic and in febrile patients with an acceptable level of diagnostic accuracy. However, further research is necessary to substantiate this finding in patients with hyperthermia.

SELDI-TOF MS Combined with Magnetic Beads for Detecting Serum Protein Biomarkers and Establishment of a Boosting Decision Tree Model for Diagnosis of Pancreatic Cancer

  • Qian, Jing-Yi;Mou, Si-Hua;Liu, Chi-Bo
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.5
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    • pp.1911-1915
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    • 2012
  • Aim: New technologies for the early detection of pancreatic cancer (PC) are urgently needed. The aim of the present study was to screen for the potential protein biomarkers in serum using proteomic fingerprint technology. Methods: Magnetic beads combined with surface-enhanced laser desorption/ionization (SELDI) TOF MS were used to profile and compare the protein spectra of serum samples from 85 patients with pancreatic cancer, 50 patients with acute-on-chronic pancreatitis and 98 healthy blood donors. Proteomic patterns associated with pancreatic cancer were identified with Biomarker Patterns Software. Results: A total of 37 differential m/z peaks were identified that were related to PC (P < 0.01). A tree model of biomarkers was constructed with the software based on the three biomarkers (7762 Da, 8560 Da, 11654 Da), this showing excellent separation between pancreatic cancer and non-cancer., with a sensitivity of 93.3% and a specificity of 95.6%. Blind test data showed a sensitivity of 88% and a specificity of 91.4%. Conclusions: The results suggested that serum biomarkers for pancreatic cancer can be detected using SELDI-TOF-MS combined with magnetic beads. Application of combined biomarkers may provide a powerful and reliable diagnostic method for pancreatic cancer with a high sensitivity and specificity.

Ovarian Malignancy Probability Score (OMPS) for Appropriate Referral of Adnexal Masses

  • Arab, Maliheh;Honarvar, Zahra;Hosseini-Zijoud, Seyed-Mostafa
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.20
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    • pp.8647-8650
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    • 2014
  • Background: Ovarian cancer is the most common cancer cause of gynecologic cancer deaths. In order to increase the likelihood of patient survival through primary operation by gyneco-oncologists, an appropriate algorithm for referral is considered here. Materials and Methods: Suspicious adnexal mass cases including ovarian malignancy probability score-1 (OMPS1) scores between 2.3-3.65 are re-evaluated by OMPS2. Sensitivity and specificity of each score were determined. Results: Sensitivity and specificity with a 3.82 score of OMPS2 in the studied subgroup (OMPS1 scores between 2.3-3.65) were 64% and 76.9% respectively. Conclusions: Management of OMPS1 scores of below 2.3 with sensitivity of 100% and above 3.65 with specificity of 72.9% is clear. In the subgroup of cases with OMPS1 score between 2.3-3.65, OMPS2 is helpful for triage with a cutoff score of 3.82.

Development of Quantitative Real-Time PCR Primers for Detection of Streptococcus sobrinus

  • Park, Soon-Nang;Kook, Joong-Ki
    • International Journal of Oral Biology
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    • v.41 no.3
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    • pp.149-154
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    • 2016
  • The purpose of this study was to develop Streptococcus sobrinus-specific qPCR primers based on the nucleotide sequence of the RNA polymerase ${\beta}-subunit$ gene (rpoB). The specificity of the primers was determined by conventional polymerase chain reaction (PCR) with 12 strains of S. sobrinus and 50 strains (50 species) of non-S. sobrinus bacteria. The sensitivity of the primers was determined by quantitative real-time PCR (qPCR) with serial dilutions of the purified genomic DNAs (40 ng to 4 fg) of S. sobrinus ATCC $33478^T$. The specificity data showed that the S. sobrinus-specific qPCR primers (RTSsob-F4/RTSsob-R4) detected only the genomic DNAs of S. sobrinus strains with a detection limit of up to 4 fg of S. sobrinus genomic DNA. Our results suggest that the RTSsob-F4/RTSsob-R4 primers are useful in detecting S. sobrinus with high sensitivity and specificity for epidemiological studies of dental caries..

Determination of the Optimal Cutoff Point using Adjusted Stratum-Specific Likelihood Ratios when Disease Verification is subject to Verification Bias (선택편향이 존재할 때, 수정 층화우도비를 이용한 최적절사점의 결정)

  • Kim, Hu-Nam;Park, Yong-Gyu
    • The Korean Journal of Applied Statistics
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    • v.20 no.3
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    • pp.515-530
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    • 2007
  • Stratum-specific likelihood ratio, which is ratio of the sensitivity to 1-the specificity in each stratum of the test, could be biased if the sensitivity and specificity of diagnostic test are affected by verification bias. Therefore, the optimal cutoff point determined by biased stratum-specific likelihood ratios is incorrect. In this study, we derived adjusted stratum-specific likelihood ratios using the adjusted sensitivity and specificity, and obtained the adjusted optimal cutoff point. The influence of the verification bias on the optimal cutoff point was described through the relation between adjusted and unadjusted stratum-specific likelihood ratios.

Reconsideration of F1 Score as a Performance Measure in Mass Spectrometry-based Metabolomics

  • Jeong, Jaesik;Kim, Han Sol;Kim, Shin June
    • Journal of Integrative Natural Science
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    • v.11 no.3
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    • pp.161-164
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    • 2018
  • Over the past decade, mass spectrometry-based metabolomics, especially two dimensional gas chromatography mass spectrometry (GCxGC/TOF-MS), has become a key analytical tool for metabolomics data because of its sensitivity and ability to analyze complex biological or biochemical sample. However, the need to reduce variations within/between experiments has been reported and methodological developments to overcome such problem has long been a critical issue. Along with methodological developments, developing reasonable performance measure has also been studied. Following four numerical measures have been typically used for comparison: sensitivity, specificity, receiver operating characteristic (ROC) curves, and positive predictive value (PPV). However, more recently, such measures are replaced with F1 score in many fields including metabolomics area without any carefulness of its validity. Thus, we want to investigate the validity of F1 score on two examples, with the goal of raising the awareness in choosing appropriate performance comparison measure. We noticed that F1 score itself, as a performance measure, was not good enough. Accordingly, we suggest that F1 score be supplemented with other performance measure such as specificity to improve its validity.

Multicenter Evaluation of Seegene Anyplex TB PCR for the Detection of Mycobacterium tuberculosis in Respiratory Specimens

  • Lim, Jinsook;Kim, Jimyung;Kim, Jong Wan;Ihm, Chunhwa;Sohn, Yong-Hak;Cho, Hyun-Jung;Kim, Jayoung;Koo, Sun Hoe
    • Journal of Microbiology and Biotechnology
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    • v.24 no.7
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    • pp.1004-1007
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    • 2014
  • Culture is the gold standard for diagnosis of tuberculosis, but it takes 6 to 8 weeks to confirm the result. This issue is complemented by the detection method using polymerase chain reaction, which is now widely used in a routine microbiology laboratory. In this study, we evaluated the performance of the Seegene Anyplex TB PCR to assess its diagnostic sensitivity and specificity, and compared its results with the Roche Cobas TaqMan MTB PCR, one of the most widely used assays in the world. Five university hospitals located in the Chungcheong area in South Korea participated in the study. A total of 1,167 respiratory specimens ordered for acid-fast bacilli staining and culture were collected for four months, analyzed via the Seegene Anyplex TB PCR, and its results were compared with the Roche Cobas TaqMan MTB PCR. For detection of Mycobacterium tuberculosis, the diagnostic sensitivity and specificity of the Anyplex TB PCR were 87.5% and 98.2% respectively, whereas those of the Cobas TaqMan were 92.0% and 98.0% respectively (p value > 0.05). For smear-positive specimens, the sensitivity of the Anyplex TB PCR was 95.2%, which was exactly the same as that of the Cobas TaqMan. For smear-negative specimens, the sensitivity of the Anyplex TB PCR was 69.2%, whereas that of the Cobas TaqMan TB PCR was 84.6%. For detection of MTB, the Seegene Anyplex TB PCR showed excellent diagnostic performance, and high sensitivity and specificity, which were comparable to the Roche Cobas TaqMan MTB PCR. In conclusion, the Anyplex TB PCR can be a useful diagnostic tool for the early detection of tuberculosis in clinical laboratories.

A Comparision of Surepath$^{TM}$ Liquid-Based Smear with a Conventional Smear for Cervicovaginal Cytology-with Reference to a Histological Diagnosis (자궁경부 조직 진단을 기준으로 Surepath$^{TM}$ 액상세포검사와 고식적 직접도말 자궁경부 세포검사법의 비교)

  • Lee, Kyung-Chul;Jung, Chan-Kwon;Jung, Eun-Sun;Choi, Yeong-Jin;Park, Jong-Sup;Lee, Kyo-Young;Lee, Ah-Won
    • The Korean Journal of Cytopathology
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    • v.18 no.1
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    • pp.20-28
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    • 2007
  • This study was performed to compare Surepath$^{TM}$ liquid-based smear and a conventional cervicovaginal smear with reference to a histological diagnosis. A hybrid capture test (HCII) was also performed and analyzed. We collected matched cases for cervicovaginal cytology-histology: 207 cases for conventional cytology (CC) and 199 cases for liquid-based cytology (LBC). HCII was performed in 254 patients. When a cytological diagnosis of ASCUS or above (ASCUS+) is classified as positive and a histological diagnosis of LSIL+ is classified as positive, the sensitivity and specificity for LBC was 91.7% and 75.9%, respectively and the sensitivity and specificity for CC was 62.6% and 96.1%, respectively. When a cytological and histological diagnosis of LSIL+ is classified as positive, the sensitivity and specificity for LBC was 77.5 and 96.6%, respectively and the sensitivity and specificity for CC was 49.7% and 100%, respectively. When a histological diagnosis of LSIL+ is classified as positive, the sensitivity and specificity for HCII was 78.9% and 78.1%, respectively. The concordance ratio between the cytological and histological diagnosis was 80.4% (kappa=76.0) for LBC and 56.5% (kappa=55.1) for CC. LBC is more sensitive and less specific then CC, as a cytological cutoff level of ASCUS, but more sensitive and equally specific, as a cytological cutoff level LSIL or HSIL. LBC is more reliable with a high concordance ratio between the cytological and histological diagnosis.

The Usefulness of Whole-blood Interferon-gamma Release Assay for the Diagnosis of Extra-pulmonary Tuberculosis (폐외 결핵에서 전혈 인터페론 감마 측정법의 진단적 유용성)

  • Lee, Hye-Min;Cho, Sung Gun;Kang, Hyung Koo;Park, Sung Woon;Lee, Byung Ook;Lee, Jae Hee;Jeon, Eun Ju;Choi, Jae Chol
    • Tuberculosis and Respiratory Diseases
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    • v.67 no.4
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    • pp.331-337
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    • 2009
  • Background: The whole-blood interferon-gamma release assay (QuantiFERON-TB Gold [QFT-G]: Cellestis, Carnegie, Victoria, Australia) has been studied primarily for the use of diagnosing active pulmonary tuberculosis (TB) or latent TB. In the present study, the usefulness of QFT-G was evaluated for the diagnosis of extra-pulmonary tuberculosis (EP-TB). Methods: From June 2006 to February 2009, we evaluated the usefulness of QFT-G in patients (n=65) suspected with EP-TB, retrospectively. The diagnostic sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the QFT-G assay were analyzed. Results: EP-TB was diagnosed in 33 (51%) participants. The overall sensitivity, specificity, PPV, and NPV of the QFT-G assay for EP-TB were 78%, 79%, 81%, and 77%, respectively. Of the 33 with EP-TB, 14 (42%) were diagnosed with TB pleurisy, 7 (21%) with TB lymphadenitis, 7 (21%) with intestinal TB, and 5 (15%) with EP-TB in other sites. In subgroup analyses according by site of infection, the QFT-G showed 86% sensitivity, 64% specificity, and 78% NPV in TB pleurisy. On the other hand, the sensitivity, specificity, and NPV of the assay were 71%, 83% and 71%, respectively in TB lymphadenitis, and 86%, 100% and 88%, respectively in intestinal TB. Among the patients with suspected alternative site EP-TB, the sensitivity, specificity, and NPV of the assay were 50%, 80% and 67%, respectively. Conclusion: The QFT-G assay showed moderate diagnostic accuracy in EP-TB. However, negative QFT-G assay does not exclude EP-TB because of the low NPV of this assay.