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Cohen's Kappa Statistic (cohen + kappa_statistic)
Selected AbstractsModelling species distributions in Britain: a hierarchical integration of climate and land-cover dataECOGRAPHY, Issue 3 2004Richard G. Pearson A modelling framework for studying the combined effects of climate and land-cover changes on the distribution of species is presented. The model integrates land-cover data into a correlative bioclimatic model in a scale-dependent hierarchical manner, whereby Artificial Neural Networks are used to characterise species' climatic requirements at the European scale and land-cover requirements at the British scale. The model has been tested against an alternative non-hierarchical approach and has been applied to four plant species in Britain: Rhynchospora alba, Erica tetralix, Salix herbacea and Geranium sylvaticum. Predictive performance has been evaluated using Cohen's Kappa statistic and the area under the Receiver Operating Characteristic curve, and a novel approach to identifying thresholds of occurrence which utilises three levels of confidence has been applied. Results demonstrate reasonable to good predictive performance for each species, with the main patterns of distribution simulated at both 10 km and 1 km resolutions. The incorporation of land-cover data was found to significantly improve purely climate-driven predictions for R. alba and E. tetralix, enabling regions with suitable climate but unsuitable land-cover to be identified. The study thus provides an insight into the roles of climate and land-cover as determinants of species' distributions and it is demonstrated that the modelling approach presented can provide a useful framework for making predictions of distributions under scenarios of changing climate and land-cover type. The paper confirms the potential utility of multi-scale approaches for understanding environmental limitations to species' distributions, and demonstrates that the search for environmental correlates with species' distributions must be addressed at an appropriate spatial scale. Our study contributes to the mounting evidence that hierarchical schemes are characteristic of ecological systems. [source] Using the cardiac depression scale in men recovering from coronary artery bypass surgeryJOURNAL OF CLINICAL NURSING, Issue 11 2009Kathryn M King Aims., To examine the utility and validate the use of the Cardiac Depression Scale in patients who had first-time coronary artery bypass graft surgery. Background., The Beck Depression Inventory, though frequently used, may not be sufficiently sensitive for use in cardiac patients. The Cardiac Depression Scale has been shown to identify the range of depression in medical cardiac patients. Design., Survey. Methods., The Beck Depression Inventory and Cardiac Depression Scale were administered to 120 men at hospital discharge, as well as six, 12 and 36 weeks postoperatively. Cronbach's , scores were calculated for the measures at each point. Changes in scores over time were analysed using repeated measures analysis of variance. Associations between the measures scores were calculated using Pearson product,moment correlations. Agreement between the measures' dichotomised scores (depression/no depression) was examined using Cohen's Kappa statistic. Results., Internal consistency was similar for the Beck Depression Inventory (0·793,0·904) and Cardiac Depression Scale (0·859,0·910). Depression scores decreased over time with the Beck Depression Inventory [F(2·50, 175·29) = 22·27, p < 0·001] and Cardiac Depression Scale [F(2·68, 190·37) = 13·18, p < 0·001]. The measures had similar power [Cohen's f = 0·65 (Beck Depression Inventory) and 0·43 (Cardiac Depression Scale)] to reveal changes over time. The continuous scores were highly correlated at each point [0·737 (p < 0·001),0·819 (p < 0·001)]. However, when dichotomised scores were compared, the chance corrected level of agreement was less impressive [0·198 (p = 0·014),0·381 (p < 0·001)]. Conclusions., The Cardiac Depression Scale may have utility for use with surgical cardiac patients. However, continued examination of this measure of depression is warranted. Relevance to clinical practice., Given the prevalence of depression and its negative impact on coronary artery disease, it is important to identify even mild depression in cardiac patients. Using a measure of depression specifically for cardiac patients, rather than a generic measure, may best accomplish this goal. [source] Inter-observer agreement for multichannel intraluminal impedance,pH testingDISEASES OF THE ESOPHAGUS, Issue 7 2010K. Ravi SUMMARY Twenty-four-hour ambulatory multichannel intraluminal impedance (MII),pH detects both acid and nonacid reflux (NAR). A computer-based program (AutoscanÔ, Sandhill Scientific, Highlands Ranch, CO, USA) automates the detection of reflux episodes, increasing the ease of study interpretation. Inter-observer agreement between multiple reviewers and with AutoscanÔ for the evaluation of significant NAR with MII,pH has not been studied in the adult population. Twenty MII,pH studies on patients taking a proton pump inhibitor twice daily were randomly selected. AutoscanÔ analyzed all studies using the same pre-programmed parameters. Four reviewers interpreted the MII,pH studies, adding or deleting reflux episodes detected by AutoscanÔ. Positive studies for NAR and total reflux episodes were based on published criteria. Cohen's kappa statistic (,) evaluated inter-observer agreement between reviewers and AutoscanÔ analysis. The average , for pathologic NAR between reviewers was 0.57 (0.47,0.70), and between reviewers and AutoscanÔ was 0.56 (0.4,0.8). When using the total reflux episode number as a marker for pathologic reflux (acid and NAR), the , score was 0.72 (0.61,0.89) between reviewers, and 0.74 (0.53,0.9) when evaluating total reflux episodes. Two reviewers agreed more often with each other and with AutoscanÔ on the number of NAR episodes, while the other two reviewers agreed with each other, but did not agree with either AutoscanÔ or the first two reviewers. Inter-observer agreement between reviewers and AutoscanÔ for detecting pathologic NAR is moderate, with reviewers either excluding more of the AutoscanÔ-defined events or excluding fewer events and therefore agreeing with AutoscanÔ. [source] Inter-Rater Reliability of the Diagnoses of Psychosis and Depression in Individuals with Intellectual DisabilitiesJOURNAL OF APPLIED RESEARCH IN INTELLECTUAL DISABILITIES, Issue 5 2007S. Einfeld Background, There is a history of over-prescription of antipsychotics to individuals with intellectual disability (ID), while antidepressants may be under-prescribed. However, appropriate treatment is best supported when the diagnosis of psychosis or depression is valid and carries good predictive validity. The present authors report a study examining one aspect of validity, namely whether skilled clinicians can agree on whether an individual with an ID is psychotic or depressed. Materials and Methods, Pairs of clinicians assessed 52 individuals. Agreement was assessed using Cohen's kappa statistic and agreement proportion. Results, Overall agreement was high for both psychosis and depression. Whether the individual had mild ID or moderate/severe ID did not have a significant impact on agreement. Conclusions, Experienced clinicians achieved a high level of agreement as to whether a person with ID was psychotic or depressed similar to that found for those without ID. The findings provide some support for treatment interventions based on diagnosis. [source] | ||||||||||