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Receiver Operator Characteristic Curve (receiver + operator_characteristic_curve)
Selected AbstractsNormal values of pulmonary capillary wedge pressure and the blood pressure response to the Valsalva manoeuvre in healthy elderly subjectsCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 6 2005Jaap J. Remmen Summary The blood pressure response to the Valsalva manoeuvre is related to pulmonary capillary wedge pressure (PCWP) and can be used to diagnose heart failure. However, this has never been studied specifically in the elderly, in whom the prevalence of heart failure is highest. Furthermore, normal values of the Valsalva manoeuvre are lacking. We aimed to obtain normal values of PCWP and the blood pressure response to the Valsalva manoeuvre in elderly subjects. Therefore, 28 healthy subjects, aged 70 ± 4 years, performed Valsalva manoeuvres before and after anti-G garment inflation, which was used for temporary increase of PCWP. Before inflation, PCWP was 9·8 ± 1·9 mmHg in supine and 8·9 ± 2·1 in semi-recumbent position. From the blood pressure response, measured with Finapres, the systolic blood pressure ratio (SBPR), pulse pressure ratio (PPR), stroke volume ratio (SVR) and heart rate ratio (HRR) were calculated. In supine position, SBPR was 0·76 ± 0·11, PPR 0·51 ± 0·16, SVR 0·42 ± 0·11, and HRR 1·17 ± 0·12. Semi-recumbently, SBPR was 0·74 ± 0·10, PPR 0·46 ± 0·14, SVR 0·41 ± 0·10, and HRR 1·24 ± 0·23. After inflation of the anti-G garment, the areas under the Receiver Operator Characteristics curves of SBPR, PPR and SVR for elevated (,15 mmHg) PCWP were >0·85 in supine position. In conclusion, this is the first study to obtain normal values of the blood pressure response to the Valsalva manoeuvre and PCWP in healthy elderly subjects, which is essential for the interpretation of patient data. The Valsalva manoeuvre showed significant discriminatory power in the detection of elevated PCWP, which underscores its potential in the non-invasive diagnosis of heart failure. [source] Diagnostic performance of clinical motor and non-motor tests of Parkinson disease: a matched case,control studyEUROPEAN JOURNAL OF NEUROLOGY, Issue 7 2008N. I. Bohnen Background and purpose:, The diagnosis of Parkinson disease (PD) is made typically on the basis of motor abnormalities. PD is now recognized to have both motor and non-motor manifestations, indicating a need for the development of reliable non-motor diagnostic tests for PD. The aim of the present study was to compare the accuracy of various clinical motor and non-motor tests for the diagnosis of PD. Methods:, Forty-five PD patients (Hoehn and Yahr stages 1,3; mean age 59.5 ± 10.0 years) and 45 healthy controls matched for gender and age completed a clinimetric motor test battery to assess limb bradykinesia, tremor and balance. Non-motor tests consisted of depression, anxiety and smell identification ratings. Area under the receiver operator characteristic curve (AUC) analysis was used. Results:, We found that smell identification was the most accurate predictor of the presence of PD within the overall group of patients and matched control subjects (AUC = 0.886) and also in the subgroups of mild severity (Hoehn and Yahr stages 1,1.5; AUC = 0.923), young-onset (AUC = 0.888) and female PD patients (AUC = 0.797). The second best diagnostic test was the grooved pegboard test for the clinically most affected body side. Conclusions:, We conclude that olfactory function is the most accurate diagnostic predictor within a heterogeneous sample of patients with PD. [source] Testing alternative models for the conservation of koalas in fragmented rural,urban landscapesAUSTRAL ECOLOGY, Issue 4 2006CLIVE A. MCALPINE Abstract Predicting the various responses of different species to changes in landscape structure is a formidable challenge to landscape ecology. Based on expert knowledge and landscape ecological theory, we develop five competing a priori models for predicting the presence/absence of the Koala (Phascolarctos cinereus) in Noosa Shire, south-east Queensland (Australia). A priori predictions were nested within three levels of ecological organization: in situ (site level) habitat (<1 ha), patch level (100 ha) and landscape level (100,1000 ha). To test the models, Koala surveys and habitat surveys (n = 245) were conducted across the habitat mosaic. After taking into account tree species preferences, the patch and landscape context, and the neighbourhood effect of adjacent present sites, we applied logistic regression and hierarchical partitioning analyses to rank the alternative models and the explanatory variables. The strongest support was for a multilevel model, with Koala presence best predicted by the proportion of the landscape occupied by high quality habitat, the neighbourhood effect, the mean nearest neighbour distance between forest patches, the density of forest patches and the density of sealed roads. When tested against independent data (n = 105) using a receiver operator characteristic curve, the multilevel model performed moderately well. The study is consistent with recent assertions that habitat loss is the major driver of population decline, however, landscape configuration and roads have an important effect that needs to be incorporated into Koala conservation strategies. [source] The predictive value of serum 1,5-anhydro-D-glucitol in pregnancies at increased risk of gestational diabetes mellitus and gestational impaired glucose toleranceBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 7 2001Wing-Hung Tam The objective of the study was to determine the efficacy of 1,5-anhydro-D-glucitol (1,5 AG) for the prediction of gestational diabetes and gestational impaired glucose tolerance (GIGT). One hundred and eighty-five pregnant women with epidemiological risk factors of gestational diabetes or GIGT underwent 75 g oral glucose tolerance test and plasma 1,5 AG assay at 26 to 28 weeks of gestation. There was no significant difference in plasma 1,5 AG either before or after an oral glucose load. The area under the receiver operator characteristic curve for 1,5 AG was only 0.485 which implies that 1,5 AG is a poor predictor of GIGT or gestational diabetes. [source] Predicting neurodevelopmental impairment in preterm infants by standardized neurological assessments at 6 and 12 months corrected ageACTA PAEDIATRICA, Issue 4 2010I Grimmer Abstract Aim:, Neurodevelopmental impairment in very preterm infants can be reasonably diagnosed by 18,24 months corrected age, whereas the predictive value of earlier assessments is debated. We hypothesized that neurological findings at 6 and 12 months indicative of subsequent cerebral palsy predict 18,24 months' neurodevelopmental impairment. Methods:, Neurodevelopmental examinations (Griffiths scales) at 20 months of age in 561 preterm infants (birth weight <1 500 g) were compared with results of standardized neurological examinations (Early Motor Pattern Profile; EMPP) and Griffiths scales at 6 (n = 451) and 12 months (n = 496) corrected age. Results:, Griffiths developmental quotients at 20 months were weakly but significantly related to EMPP scores at 6 (Rs = 0.328) and 12 months (Rs = 0.493). Areas under receiver operator characteristic curves for the EMPP to predict neurodevelopmental impairment (Griffiths scores ,75) at 20 months were 0.772 (0.890) at 6 (12) months, compared to 0.915 (0.962) for Griffiths scores. By contrast, EMPP and Griffiths scores had equal power to predict unability to walk unaided at 2 years of age (EMPP 6/12 months: 0.946/0.983; Griffiths 6/12 months: 0.935/0.985). Conclusion:, Neurological examinations with the EMPP at 6 and 12 months corrected age are of limited value to predict neurodevelopmental impairment at 20 months. [source] | ||||||||||