scholarly journals Dual Tasking With the Timed “Up & Go” Test Improves Detection of Risk of Falls in People With Parkinson Disease

2015 ◽  
Vol 95 (1) ◽  
pp. 95-102 ◽  
Author(s):  
Roisin C. Vance ◽  
Dan G. Healy ◽  
Rose Galvin ◽  
Helen P. French
Keyword(s):  
Parkinson Disease ◽  
Receiver Operating Characteristic ◽  
Likelihood Ratio ◽  
Sensitivity And Specificity ◽  
Fall Risk ◽  
Operating Characteristic ◽  
Risk Of Falling ◽  
Discriminative Performance ◽  
Study Objective ◽  
Receiver Operating

BackgroundFalls are a common and disabling feature of Parkinson disease (PD). Early identification of patients at greatest risk of falling is a key goal of physical therapy assessment. The Timed “Up & Go” Test (TUG), a frequently used mobility assessment tool, has moderate sensitivity and specificity for identifying fall risk.ObjectiveThe study objective was to investigate whether adding a task (cognitive or manual) to the TUG (TUG-cognitive or TUG-manual, respectively) increases the utility of the test for identifying fall risk in people with PD.DesignThis was a retrospective cohort study of people with PD (N=36).MethodsParticipants were compared on the basis of self-reported fall exposure in the preceding 6 months (those who had experienced falls [“fallers”] versus those who had not [“nonfallers”]). The time taken to complete the TUG, TUG-cognitive, and TUG-manual was measured for both groups. Between-group differences were calculated with the Mann-Whitney U test. The discriminative performance of the test at various cutoff values was examined, and estimates of sensitivity and specificity were based on receiver operating characteristic curve plots.ResultsFallers took significantly longer than nonfallers (n=19) to complete the TUG under all 3 conditions. The TUG-cognitive showed optimal discriminative performance (receiver operating characteristic area under the curve=0.82; 95% confidence interval [CI]=0.64, 0.92) at a cutoff of 14.7 seconds. The TUG-cognitive was more likely to correctly classify participants with a low risk of falling (positive likelihood ratio=2.9) (<14.7 seconds) and had higher estimates of sensitivity (0.76; 95% CI=0.52, 0.90) than of specificity (0.73; 95% CI=0.51, 0.88) at this threshold (negative likelihood ratio=0.32).LimitationsRetrospective classification of fallers and nonfallers was used.ConclusionsThe addition of a cognitive task to the TUG enhanced the identification of fall risk in people with PD. The TUG-cognitive should be considered a component of a multifaceted fall risk assessment in people with PD.

Diagnostic studies

2010 ◽  
pp. 339-351
Author(s):  
Janet L. Peacock ◽  
Philip J. Peacock
Keyword(s):  
Receiver Operating Characteristic ◽  
Likelihood Ratio ◽  
Sensitivity And Specificity ◽  
Operating Characteristic ◽  
Characteristic Curve ◽  
Diagnostic Testing ◽  
Roc Curves ◽  
Clinical Situation ◽  
Post Test ◽  
Receiver Operating

Sensitivity and specificity 340 Calculations for sensitivity and specificity 342 Effect of prevalence 344 Likelihood ratio, pre-test odds, post-test odds 346 Receiver operating characteristic (ROC) curves 348 Links to other statistics 350 In this chapter we describe how statistical methods are used in diagnostic testing to obtain different measures of a test’s performance. We describe how to calculate sensitivity, specificity, and positive and negative predictive values, and show the relevance of pre- and post-test odds and likelihood ratio in evaluating a test in a clinical situation. We also describe the receiver operating characteristic curve and show how this links with logistic regression analysis. All methods are illustrated with examples....

scholarly journals Accuracy and adequacy of waist circumference cut-off points currently recommended in Brazilian adults

2013 ◽  
Vol 17 (4) ◽  
pp. 861-869 ◽  
Author(s):  
Carolina Avila Vianna ◽  
Rogério da Silva Linhares ◽  
Renata Moraes Bielemann ◽  
Eduardo Coelho Machado ◽  
David Alejandro González-Chica ◽  
...  
Keyword(s):  
Cardiovascular Risk ◽  
Waist Circumference ◽  
Receiver Operating Characteristic ◽  
Sensitivity And Specificity ◽  
Operating Characteristic ◽  
Characteristic Curve ◽  
Predictive Ability ◽  
Youden Index ◽  
Southern Brazil ◽  
Receiver Operating

AbstractObjectiveTo evaluate the adequacy and accuracy of cut-off values currently recommended by the WHO for assessment of cardiovascular risk in southern Brazil.DesignPopulation-based study aimed at determining the predictive ability of waist circumference for cardiovascular risk based on the use of previous medical diagnosis for hypertension, diabetes mellitus and/or dyslipidaemia. Descriptive analysis was used for the adequacy of current cut-off values of waist circumference, receiver operating characteristic curves were constructed and the most accurate criteria according to the Youden index and points of optimal sensitivity and specificity were identified.SettingPelotas, southern Brazil.SubjectsIndividuals (n2112) aged ≥20 years living in the city were selected by multistage sampling, since these individuals did not report the presence of previous myocardial infarction, angina pectoris or stroke.ResultsThe cut-off values currently recommended by WHO were more appropriate in men than women, with overestimation of cardiovascular risk in women. The area under the receiver operating characteristic curve showed moderate predictive ability of waist circumference in men (0·74, 95 % CI 0·71, 0·76) and women (0·75, 95 % CI 0·73, 0·77). The method of optimal sensitivity and specificity showed better performance in assessing the accuracy, identifying the values of 95 cm in men and 87 cm in women as the best cut-off values of waist circumference to assess cardiovascular risk.ConclusionsThe cut-off values currently recommended for waist circumference are not suitable for women. Longitudinal studies should be conducted to evaluate the consistency of the findings.

scholarly journals Systematic Review with Meta-Analysis: Fecal Calprotectin as a Surrogate Marker for Predicting Relapse in Adults with Ulcerative Colitis

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Jiajia Li ◽  
Xiaojing Zhao ◽  
Xueting Li ◽  
Meijiao Lu ◽  
Hongjie Zhang
Keyword(s):  
Ulcerative Colitis ◽  
Receiver Operating Characteristic ◽  
Likelihood Ratio ◽  
Odds Ratio ◽  
Operating Characteristic ◽  
Diagnostic Odds Ratio ◽  
Fecal Calprotectin ◽  
Clinical Relapse ◽  
Sensitivity Specificity ◽  
Receiver Operating

The clinical course of ulcerative colitis (UC) is featured by remission and relapse, which remains unpredictable. Recent studies revealed that fecal calprotectin (FC) could predict clinical relapse for UC patients in remission, which has not yet been well accepted. To detect the predictive value of FC for clinical relapse in adult UC patients based on updated literature, we carried out a comprehensive electronic search of PubMed, Web of Science, Embase, and the Cochrane Library to identify all eligible studies. Diagnostic accuracy including pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and pooled area under the receiver operating characteristic (AUROC) was calculated using a random effects model. Heterogeneity across studies was assessed by the I2 metric. Sources of heterogeneity were detected using subgroup analysis. Metaregression was used to test potential factors correlated to DOR. Publication bias was assessed using Deek’s funnel plots. In our study, 14 articles enrolling a total of 1110 participants were finally included, and all articles underwent a quality assessment. Pooled sensitivity, specificity, PLR, and NLR with 95% confidence intervals (CIs) were 0.75 (95% CI: 0.70–0.79), 0.77 (95% CI: 0.74–0.80), 3.45 (95% CI: 2.31–5.14), and 0.37 (95% CI: 0.28–0.49) respectively. The area under the summary receiver operating characteristic (sROC) curve was 0.82, and the diagnostic odds ratio was 10.54 (95% CI: 6.16–18.02). Our study suggested that FC is useful in predicting clinical relapse for adult UC patients in remission as a simple and noninvasive marker.

scholarly journals Skor Prediksi Kematian Pneumonia pada Anak Usia di Bawah Lima Tahun

Sari Pediatri ◽  
2017 ◽  
Vol 18 (3) ◽  
pp. 214
Author(s):  
Ambarsari Latumahina ◽  
Rina Triasih ◽  
Kristia Hermawan
Keyword(s):  
Receiver Operating Characteristic ◽  
Likelihood Ratio ◽  
Operating Characteristic ◽  
Receiver Operating

Latar belakang. Pneumonia merupakan penyebab utama kematian pada anak usia di bawah lima tahun di negara berkembang. Pengembangan sistem skor yang sederhana untuk memprediksi kematian pada pneumonia dapat meningkatkan kualitas pelayanan dan menurunkan angka kematian anak akibat pneumonia.Tujuan. Menyusun skor prediksi kematian pada anak dengan pneumonia.Metode. Penelitian kohort retrospektif pada anak (umur 2 bulan sampai 5 tahun) yang dirawat di RSUP Dr. Sardjito dengan pneumonia sejak Januari 2009 sampai Desember 2014. Anak dengan rekam medis tidak lengkap atau dengan infeksi HIV dieksklusi. Digunakan metode Spiegelhalter Knill-Jones untuk penyusunan skor kematian. Prediktor kematian dengan likelihood ratio (LHR) ≤0,5 atau ≥2 dimasukkan dalam sistem skor. Cut off point dari skor total ditentukan dengan kurva receiver operating characteristic (ROC).Hasil. Di antara 225 anak yang memenuhi kriteria, 42 (18,7%) meninggal. Prediktor kematian yang memenuhi kriteria LHR adalah usia <6 bulan (LHR 2,05), takikardia (LHR 2,11), saturasi oksigen (SpO2) <92% (LHR 2,54), anemia (LHR 0,38) dan leukositosis (LHR 2,04). Skor prediksi kematian terdiri atas usia (skor=5 bila usia <6 bulan dan 0 bila >6 bulan); frekuensi nadi skor=6 bila takikardia dan -8 bila normal); saturasi oksigen (skor=3 bila SpO2 <92% dan 0 bila SpO2 >92%); hemoglobin (skor=4 bila anemia dan -6 bila normal), leukosit (skor=3 bila leukosit dan 0 bila normal). Total skor >3 Mempunyai sensitivitas dan spesifitas terbaik, yaitu 85,7% dan 72,1%.Kesimpulan. Skor prediksi kematian pneumonia >3 dapat digunakan untuk memprediksi kematian pada anak dengan pneumonia.

scholarly journals 215 Assessment of the Diagnostic Sensitivity and Specificity of Pain Biomarkers in Cattle Using Receiver Operating Characteristic Curves

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 7-8
Author(s):  
Miriam S Martin ◽  
Michael Kleinhenz ◽  
Karen Schwartzkopf-Genswein ◽  
Johann Coetzee
Keyword(s):  
Diagnostic Accuracy ◽  
Receiver Operating Characteristic ◽  
Sensitivity And Specificity ◽  
Predictive Value ◽  
Roc Analysis ◽  
Operating Characteristic ◽  
Diagnostic Sensitivity ◽  
Diagnostic Sensitivity And Specificity ◽  
Good Diagnostic Accuracy ◽  
Receiver Operating

Abstract Biomarkers are commonly used to assess pain and analgesic drug efficacy in livestock. However, the diagnostic sensitivity and specificity of these biomarkers for different pain conditions over time have not been described. Receiver operating characteristic (ROC) curves are graphical plots that illustrate the diagnostic ability of a test as its discrimination threshold is varied. The objective of this analysis was to use area under the curve (AUC) values derived from ROC analysis to assess the predictive value of pain biomarkers at specific timepoints. The biomarkers included in the analysis were blood cortisol, salivary cortisol, hair cortisol, infrared thermography (IRT), mechanical nociceptive threshold (MNT), substance P, and outcomes from a pressure/force measurement system and visual analog scale. A total sample size of 7,992 biomarker outcomes were collected from 6 pain studies involving pain associated with castration, dehorning, lameness, and surgery were included in the analysis. Each study consisted of three treatments; pain, no pain, and analgesia. All statistics were performed using statistical software (JMP Pro 14.0, SAS Institute, Inc., Cary, NC). Results comparing analgesia verses pain yielded good diagnostic accuracy (AUC &gt; 0.7; 95% CI: 0.40 to 0.99) for blood cortisol (timepoints 1.5, 2, and 6 hours); IRT (timepoints 6, 8, 12, and 72 hours); and MNT (timepoints 6, 25, and 49 hours). These results indicate that ROC analysis can be a useful indicator of the predictive value of pain biomarkers and certain timepoints seem to yield good diagnostic accuracy while many do not.

Overall severities of gastrointestinal symptoms in pediatric outpatients with and without autism spectrum disorder

Autism ◽  
2018 ◽  
Vol 23 (2) ◽  
pp. 524-530 ◽  
Author(s):  
Venkatraman Thulasi ◽  
Robert A Steer ◽  
Iona M Monteiro ◽  
Xue Ming
Keyword(s):  
Autism Spectrum Disorder ◽  
Receiver Operating Characteristic ◽  
Sensitivity And Specificity ◽  
Operating Characteristic ◽  
Gastrointestinal Disorder ◽  
Severity Index ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
Gastrointestinal Disorders ◽  
Receiver Operating

In order to determine the effectiveness of a Gastrointestinal Severity Index to screen for gastrointestinal disorders, the Gastrointestinal Severity Index was administered to 135 children with autism spectrum disorders and 146 comparisons with and without gastrointestinal disorders. The mean Gastrointestinal Severity Index scores of the groups were 3.53 ± 1.78, 3.15 ± 1.99, 0.81 ± 1.25, and 0.29 ± 0.76 (comparative pediatric patients with gastrointestinal disorder = autism spectrum disorder + gastrointestinal disorder > autism spectrum disorder-gastrointestinal disorder > comparative pediatric patients without gastrointestinal disorder, respectively), Ps < 0.05. Receiver operating characteristic curves and areas under the receiver operating characteristic curves were calculated to ascertain which Gastrointestinal Severity Index cutoff scores yielded the highest sensitivity and specificity rates for the diagnosis of gastrointestinal disorders. The area under the receiver operating characteristic curve (0.97) for the comparison group was higher (P < 0.001) than the area under the receiver operating characteristic curve (0.85) for autism spectrum disorder children indicating that the Gastrointestinal Severity Index was more effective in screening for gastrointestinal disorders in comparisons. However, the same Gastrointestinal Severity Index cutoff score of 2 and above yielded, respectively, sensitivity and specificity rates of 92% and 93% for comparisons and 80% and 79% for autism spectrum disorder children. The negative and positive predictive values based on these sensitivity and specificity rates were calculated for a range of prevalences of gastrointestinal disorders and indicated that the Gastrointestinal Severity Index may be useful for screening children with and without autism spectrum disorder for gastrointestinal symptoms.

A simple method to estimate the time-dependent receiver operating characteristic curve and the area under the curve with right censored data

2016 ◽  
Vol 27 (8) ◽  
pp. 2264-2278 ◽  
Author(s):  
Liang Li ◽  
Tom Greene ◽  
Bo Hu
Keyword(s):  
Receiver Operating Characteristic Curve ◽  
Receiver Operating Characteristic ◽  
Sensitivity And Specificity ◽  
Operating Characteristic ◽  
Characteristic Curve ◽  
Disease Onset ◽  
Area Under The Curve ◽  
Time Dependent ◽  
Operating Characteristic Curve ◽  
Receiver Operating

The time-dependent receiver operating characteristic curve is often used to study the diagnostic accuracy of a single continuous biomarker, measured at baseline, on the onset of a disease condition when the disease onset may occur at different times during the follow-up and hence may be right censored. Due to right censoring, the true disease onset status prior to the pre-specified time horizon may be unknown for some patients, which causes difficulty in calculating the time-dependent sensitivity and specificity. We propose to estimate the time-dependent sensitivity and specificity by weighting the censored data by the conditional probability of disease onset prior to the time horizon given the biomarker, the observed time to event, and the censoring indicator, with the weights calculated nonparametrically through a kernel regression on time to event. With this nonparametric weighting adjustment, we derive a novel, closed-form formula to calculate the area under the time-dependent receiver operating characteristic curve. We demonstrate through numerical study and theoretical arguments that the proposed method is insensitive to misspecification of the kernel bandwidth, produces unbiased and efficient estimators of time-dependent sensitivity and specificity, the area under the curve, and other estimands from the receiver operating characteristic curve, and outperforms several other published methods currently implemented in R packages.

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