Determination of the optimal cutoff value for a serological assay: an example using the Johne's Absorbed EIA.

Introduction The Purdue Pegboard Test (PPT) is crucial for assessing fine dexterity of patients with hand injury. Determining the PPT cutoff value is needed to distinguish patients with impaired hand dexterity from those with unimpaired hand dexterity. The aim of this article is to examine the construct validity of PPT and to determine its cutoff values for patients with hand injuries. Method The PPT and Disabilities of Arm Shoulder and Hand Questionnaire Turkish version (DASH-T) were used to measure hand dexterity. To examine construct validity, we measured the correlation between PPT and DASH-T. The cutoff values were determined using the receiver operating characteristic (ROC) curve generated with sensitivity and 1-specificity. We recruited 101 patients with hand injury and 162 healthy participants. Results Correlation between all subtests of PPT and DASH-T were weak ( r = −0.282; −0.473: p<0.05). The cutoff value for the assembly subtest of PPT was 24.5. The range of area under the curve (AUC) values for PPT subtests was good to excellent (AUC: 0.82–0.92). Conclusion The current study demonstrates that PPT is a valid instrument for measuring hand dexterity in patients with hand injury. Results also suggest that PPT distinguished the patients with impaired hand function from those with unimpaired hand dexterity.

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A Novel “Maximizing Kappa” Approach for Assessing the Ability of a Diagnostic Marker and Its Optimal Cutoff Value

Journal of Biopharmaceutical Statistics ◽

10.1080/10543406.2014.920347 ◽

2014 ◽

Vol 25 (5) ◽

pp. 1005-1019 ◽

Cited By ~ 1

Author(s):

Chia-Hao Chang ◽

Jen-Tsung Yang ◽

Ming-Hsueh Lee

Keyword(s):

Diagnostic Marker ◽

Optimal Cutoff ◽

Cutoff Value

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Optimal cutoff value of assessing changes in intrahepatic fat amount by using the controlled attenuation parameter in a longitudinal setting

Journal of Hepatology ◽

10.1016/s0168-8278(18)31415-6 ◽

2018 ◽

Vol 68 ◽

pp. S578

Author(s):

B.-K. Kang ◽

D.W. Jun ◽

M.M. Kim ◽

S.B. Ahn ◽

Y.C. Joo ◽

...

Keyword(s):

Controlled Attenuation Parameter ◽

Optimal Cutoff ◽

Cutoff Value ◽

Attenuation Parameter

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Association between HbA1C (glycated hemoglobin) and clinical outcomes in patients with subarachnoid hemorrhage after neuro-intervention

Current Neurovascular Research ◽

10.2174/1567202618666210225103057 ◽

2021 ◽

Vol 18 ◽

Author(s):

Chan Woong Park ◽

Ho Jun Yi ◽

Dong Hoon Lee ◽

Jae Hoon Sung

Keyword(s):

Subarachnoid Hemorrhage ◽

Clinical Outcome ◽

Clinical Outcomes ◽

Glycated Hemoglobin ◽

Aneurysmal Subarachnoid Hemorrhage ◽

Roc Curve Analysis ◽

Optimal Cutoff ◽

Cutoff Value ◽

Unfavorable Clinical Outcome ◽

High Hba1c

Objective: Our study investigated the association between level of HbA1c (glycated hemoglobin) at admission and the prognosis of aneurysmal subarachnoid hemorrhage (SAH). Methods: A total of 510 patients treated with neuro-intervention for aneurysmal SAH and with data for admission HbA1c (glycated hemoglobin) were included. Favorable clinical outcome was defined as Modified Rankin Scale (mRS) score of 0–2 at 3 months. Receiver operating characteristic (ROC) curve analysis was used to identify the optimal cutoff value of HbA1C for unfavorable clinical outcomes. Logistic regression was used to evaluate the association between HbA1C level and outcomes. Results: The optimal cutoff value of HbA1C was identified as 6.0% (P < 0.001), and patients with a high HbA1C (≥ 6.0%) had a lower prevalence of favorable clinical outcomes than patients with low HbA1C (< 6.0%) (P < 0.001). High HbA1C (≥ 6.0%) was independently associated with unfavorable clinical outcome (OR 2.84; 95% CI: 1.52-5.44; P = 0.004). The risk of unfavorable clinical outcome was significantly increased in patients with HbA1C (≥ 7.0%, < 8%) and HbA1C (≥ 8.0%) compared with lower baseline HbA1C (≥ 6.0%, < 7%) values (OR 2.17; 95% CI: 1.87-5.13; P = 0.011 and OR 4.25; 95% CI: 3.17-8.41; P = 0.005). Conclusions: Our study showed that HbA1C could be an independent predictor of worse outcome following neuro-intervention for aneurysmal SAH. High HbA1C (≥ 6.0%) was associated with unfavorable clinical outcome, and gradual elevation of HbA1C contributed to an increase in the risk of worse clinical outcome after SAH.

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Analytical and clinical evaluation of an electrochemiluminescence immunoassay for the determination of CA 125

Clinical Chemistry ◽

10.1093/clinchem/44.12.2530 ◽

1998 ◽

Vol 44 (12) ◽

pp. 2530-2536 ◽

Cited By ~ 25

Author(s):

Huub E van Ingen ◽

Daniel W Chan ◽

Walter Hubl ◽

Hayato Miyachi ◽

Rafael Molina ◽

...

Keyword(s):

Multicenter Trial ◽

Ca 125 ◽

Newly Diagnosed ◽

Cutoff Value ◽

Gynecological Diseases ◽

Electrochemiluminescence Immunoassay ◽

Benign Gynecological Diseases ◽

International Multicenter ◽

Apparently Healthy

Abstract The CA 125 II assay on the Elecsys® 2010 analyzer was evaluated in an international multicenter trial. Imprecision studies yielded within-run CVs of 0.8–3.3% and between-day CVs of 2.4–10.9%; CVs for total imprecision in the manufacturer’s laboratory were 2.4–7.8%. The linear range of the assay extended to at least 4500 kilounits/L (three decades). Interference from triglycerides (10.3 mmol/L), bilirubin (850 μmol/L), hemoglobin (1.1 mmol/L), anticoagulants (plasma), and several widely used drugs was undetectable. Method comparisons with five other CA 125 II assays showed good correlation but differences in standardization. A 95th percentile cutoff value of 35 kilounits/L was calculated from values measured in 593 apparently healthy (pre- and postmenopausal) women. In 95% of patients with benign gynecological diseases CA 125 was ≤190 kilounits/L; 63% of patients with newly diagnosed ovarian carcinoma had values >190 kilounits/L. A comparison of CA 125 values obtained with the Elecsys test and with other common CA 125 tests in monitored patients being treated for ovarian cancer showed identical patterns. In conclusion, the Elecsys CA 125 II assay is linear over a broad range, yields precise and accurate results, is free from interferences, and compares well with other assays.

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D-dimer as a biomarker for assessment of COVID-19 prognosis: D-dimer levels on admission and its role in predicting disease outcome in hospitalized patients with COVID-19

PLoS ONE ◽

10.1371/journal.pone.0256744 ◽

2021 ◽

Vol 16 (8) ◽

pp. e0256744

Author(s):

Ayusha Poudel ◽

Yashasa Poudel ◽

Anurag Adhikari ◽

Barun Babu Aryal ◽

Debika Dangol ◽

...

Keyword(s):

Proportional Hazards ◽

Characteristic Curve ◽

Area Under The Curve ◽

Respiratory Illness ◽

Immunofluorescence Assay ◽

Cox Proportional Hazards ◽

Optimal Cutoff ◽

Cutoff Value ◽

Potential Biomarker ◽

D Dimer

Introduction Coronavirus Disease 2019 is a primarily respiratory illness that can cause thrombotic disorders. Elevation of D-dimer is a potential biomarker for poor prognosis in COVID-19, though optimal cutoff value for D-dimer to predict mortality has not yet been established. This study aims to assess the accuracy of admission D-dimer in the prognosis of COVID-19 and to establish the optimal cutoff D-dimer value to predict hospital mortality. Methods Clinical and laboratory parameters and outcomes of confirmed COVID-19 cases admitted to four hospitals in Kathmandu were retrospectively analyzed. Admitted COVID-19 cases with recorded D-dimer and definitive outcomes were included consecutively. D-dimer was measured using immunofluorescence assay and reported in Fibrinogen Equivalent Unit (μg/ml). The receiver operating characteristic curve was used to determine the accuracy of D-dimer in predicting mortality, and to calculate the optimal cutoff value, based on which patients were divided into two groups and predictive value of D-dimer for mortality was measured. Results 182 patients were included in the study out of which 34(18.7%) died during the hospital stay. The mean admission D-dimer among surviving patients was 1.067 μg/ml (±1.705 μg/ml), whereas that among patients who died was 3.208 μg/ml (±2.613 μg/ml). ROC curve for D-dimer and mortality gave an area under the curve of 0.807 (95% CI 0.728–0.886, p<0.001). Optimal cutoff value for D-dimer was 1.5 μg/ml (sensitivity 70.6%, specificity 78.4%). On Cox proportional hazards regression analysis, the unadjusted hazard ratio for high D-dimer was 6.809 (95% CI 3.249–14.268, p<0.001), and 5.862 (95% CI 2.751–12.489, p<0.001) when adjusted for age. Conclusion D-dimer value on admission is an accurate biomarker for predicting mortality in patients with COVID-19. 1.5 μg/ml is the optimal cutoff value of admission D-dimer for predicting mortality in COVID-19 patients.

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The Optimal Cutoff Value of D-dimer Levels to Predict in Hospital Mortality in Severe Cases of Coronavirus Disease 2019

Open Access Macedonian Journal of Medical Sciences ◽

10.3889/oamjms.2021.7600 ◽

2021 ◽

Vol 9 (B) ◽

pp. 1561-1564

Author(s):

Ngakan Ketut Wira Suastika ◽

Ketut Suega

Keyword(s):

Hospital Mortality ◽

Receiver Operating Characteristic Curve ◽

Receiver Operating Characteristic ◽

Operating Characteristic ◽

Characteristic Curve ◽

Area Under The Curve ◽

Optimal Cutoff ◽

Cutoff Value ◽

Operating Characteristic Curve ◽

D Dimer

Introduction: Coronavirus disease 2019 (Covid-19) can cause coagulation parameters abnormalities such as an increase of D-dimer levels especially in severe cases. The purpose of this study is to determine the differences of D-dimer levels in severe cases of Covid-19 who survived and non-survived and determine the optimal cut-off value of D-dimer levels to predict in-hospital mortality. Method: Data were obtained from confirmed Covid-19 patients who were treated from June to September 2020. The Mann-Whitney U test was used to determine differences of D-dimer levels in surviving and non-surviving patients. The optimal cut-off value and area under the curve (AUC) of the D-dimer level in predicting mortality were obtained by the receiver operating characteristic curve (ROC) method. Results: A total of 80 patients were recruited in this study. Levels of D-dimer were significantly higher in non-surviving patients (median 3.346 mg/ml; minimum – maximum: 0.939 – 50.000 mg/ml) compared to surviving patients (median 1.201 mg/ml; minimum – maximum: 0.302 – 29.425 mg/ml), p = 0.012. D-dimer levels higher than 1.500 mg/ml are the optimal cut-off value for predicting mortality in severe cases of Covid-19 with a sensitivity of 80.0%; specificity of 64.3%; and area under the curve of 0.754 (95% CI 0.586 - 0.921; p = 0.010). Conclusions: D-dimer levels can be used as a predictor of mortality in severe cases of Covid-19.

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