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Kappa Index (kappa + index)

Distribution by Scientific Domains

Medical Sciences	71%

Selected Abstracts

An investigation of the hydrological requirements of River Red Gum (Eucalyptus camaldulensis) Forest, using Classification and Regression Tree modelling

ECOHYDROLOGY, Issue 2 2009
Li Wen
Abstract River Red Gum (Eucalyptus camaldulensis) is widely distributed throughout many water courses and floodplains within inland Australia. In recent years, accelerated decline of River Red Gum condition has been observed in many locations, and field observations of the degradation are consistent with the reduction of flooding. However, there are few publications that quantitatively investigate the relationships between River Red Gum condition and flooding history. We applied Classification and Regression Tree (CART) to model the minimum flooding requirement of River Red Gum forest/woodland in Yanga National Park, located on the Lower Murrumbidgee Floodplain, southeast Australia, using crown conditions derived from historical aerial photographs spanning more than 40 years. The model produced has a moderate reliability with an overall accuracy of 64·1% and a Kappa index of 0·543. The model brings in important insights about the relationship between River Red Gum community type, flood frequency and flood duration. Our results demonstrated that (1) CART analysis is a simple yet powerful technique with significant potential for application in river and environmental flow management; (2) River Red Gum communities on the Lower Murrumbidgee Floodplain require periodic inundation (3,5 years) for a duration of up to 64 days to be in moderate to good conditions; (3) Although the crown conditions of different community types displayed similar degradation trends, they have distinct flooding requirements; and (4) The River Red Gum community in Yanga National Park may be managed as hydrological units given limited environmental water allocations. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Peritoneal carcinomatosis from colorectal or appendiceal origin: Correlation of preoperative CT with intraoperative findings and evaluation of interobserver agreement

JOURNAL OF SURGICAL ONCOLOGY, Issue 2 2004
Eelco de Bree MD
Abstract Background and Objectives In patients with colorectal cancer, it is important to diagnose peritoneal carcinomatosis as well as to detect location and size of peritoneal tumor dissemination in view of treatment planning. The aim of this study was to investigate the detection accuracy of computed tomography (CT). Methods Preoperative CT-scans from 25 consecutive patients with peritoneal carcinomatosis from colorectal or appendiceal origin were independently blindly reviewed by 2 radiologists. The presence and diameter of tumor deposits were noted in seven abdominopelvic areas. Intraoperative findings were regarded as the gold standard. Agreement was assessed using the Kappa index and the chi-square test. Results The presence of peritoneal carcinomatosis was detected in 60 and 76% of those patients by each of the radiologist. Detection of individual peritoneal implants was poor (,,=,0.11/0.23) and varied from 9.1%/24.3% for tumor size <1 cm to 59.3%/66.7% for tumor size >5 cm. Overall sensitivity, specificity, accuracy, positive (PPV) and negative predictive value (NPV) for tumor involvement per area were 24.5%/37.3%, 94.5%/90.4%, 53.0%/60.0%, 86.2%/84.4%, and 47.3%/50.8%, respectively. Accuracy of tumor detection varied widely per anatomic site. Statistically significant interobserver differences were noted, specifically for tumor size of 1,5 cm (P,=,0.007) and localization on mesentery and small bowel (,,=,0.30, P,=,0.04). Conclusions In colorectal cancer, CT detection of peritoneal carcinomatosis is moderate and of individual peritoneal tumor deposits poor. Interobserver differences are statistically significant. Therefore, preoperative CT seems not to be a reliable tool for detection of presence, size, and location of peritoneal tumor implants in view of treatment planning in patients with colorectal cancer. J. Surg. Oncol. 2004;86:64,73. © 2004 Wiley-Liss, Inc. [source]

Mini Nutritional Assessment in geriatric rehabilitation: Inter-rater reliability and relationship to body composition and nutritional biochemistry

NUTRITION & DIETETICS, Issue 3 2007
Sonja A. NEUMANN
Abstract Aim:, To determine the inter-rater reliability of the Mini Nutritional Assessment (MNA) and relationship with body composition and nutritional biochemistry among older Australians undergoing rehabilitation. Methods:, Thirty-eight adults aged ,65 years were prospectively and consecutively recruited from an Australian rehabilitation ward. Two dietitians independently administered the 18-item MNA to determine inter-rater reliability. MNA classifications (well nourished, at risk of malnutrition, malnourished) were compared with body composition (using dual-energy X-ray absorptiometry) and serum albumin. These analyses were also performed for the short-form version of the MNA (six items). Results:, In this cross-sectional study, inter-rater reliability of the 18-item MNA score, estimated by the intraclass correlation coefficient, was 0.833, while inter-rater reliability estimated by the weighted kappa index was 0.53. The two raters reached agreement on MNA classification for 26 of 38 cases (68%). Women classified as malnourished/at risk of malnutrition using the 18-item MNA had lower total body fat (11 kg vs 29 kg, P < 0.01) and per cent body fat (25% vs 40%, P < 0.01), compared with women classified as well nourished. Similar findings were not apparent for men, although men classified as malnourished/at risk of malnutrition had lower serum albumin (32 g/L vs 36 g/L, P = 0.04) compared with men classified as well nourished. Similar findings were evident for the short-form version of the MNA. Conclusion:, The MNA was found to be useful for identifying older women with lower body fat in the Australian rehabilitation setting. The 18-item MNA score has substantial inter-rater reliability, and fair inter-rater reliability when used according to the classifications. Inclusion of subjective and self-reported items in surveys can be problematic for optimal reliability as can the use of such items in a subject population that is experiencing rapid progress in recovery. [source]

Inter-expert agreement of seven criteria in causality assessment of adverse drug reactions

BRITISH JOURNAL OF CLINICAL PHARMACOLOGY, Issue 4 2007
Yannick Arimone
What is already known about this subject ,,In pharmacovigilance, many methods have been proposed for causality assessment of adverse drug reactions. ,,Expert judgement is commonly used to evaluate the causal relationship between a drug treatment and the occurrence of an adverse event. This form of judgement relies either explicitly or implicitly on causality criteria. What this study adds ,,Our study compares the judgements of five senior experts using global introspection about drug causation and seven causality criteria on a random set of putative adverse drug reactions. ,,Even if previous publications have shown poor agreement between experts using global introspection, few have compared judgements of well trained pharmacologists, familiar with using a standardized causality assessment method. Aims To evaluate agreement between five senior experts when assessing seven causality criteria and the probability of drug causation. Methods A sample of 31 adverse event-drug pairs was constituted. For each pair, five experts separately assessed (i) the probability of drug causation, which was secondarily divided into seven causality levels: ruled out (0,0.05), unlikely (0.06,0.25), doubtful (0.26,0.45), indeterminate (0.46,0.55), plausible (0.56,0.75), likely (0.76,0.95), and certain (0.96,1); and (ii) seven causality criteria. To test discrepancies between experts, the kappa index was used. Results The agreement of the five experts was very poor (kappa = 0.05) for the probability of drug causation. Among the seven levels of causality, only ,doubtful' showed a significant rate of agreement (kappa = 0.32, P < 0.001). For all criteria, the kappa index was significant except for the item ,risk(s) factor(s)' (kappa = 0.09). Agreement between experts was good (0.64, P < 0.001) only for the criterion ,reaction at site of application or toxic plasma concentration of the drug or validated test'. However, the rate of agreement with kappa indices of the causality criteria ranged from 0.12 to 0.38. Conclusions This study confirms that in the absence of an operational procedure, agreement between experts is low. This should be considered when designing a causality assessment method. In particular, criteria inducing a low level of agreement should have their weight reduced. [source]

A Comparative Study of Computed Tomography and Magnetic Resonance Imaging for the Detection of Mandibular Canals and Cross-Sectional Areas in Diagnosis prior to Dental Implant Treatment

CLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 2 2004
Hideyuki Imamura DDS
ABSTRACT Background: Computed tomography (CT) is effective in the diagnosis of dental implants. However, it has the disadvantage of exposing patients to high doses of x-rays, and the mandibular canals cannot be detected by CT in some clinical cases. Purpose: The purpose of this study was to examine the detectability of the anatomic morphology of the molar region in the lower jaw (where implantation is common) by CT and magnetic resonance imaging (MRI), to compare the data, and to determine the usefulness of MRI in diagnosis prior to dental implant treatments. Materials and Methods: Eleven female subjects (average age, 59 years) who had partially edentulous mandibles (total of 19 sites) were included in the study. CT and MRI were performed with the same subjects, and the degrees of identification of the mandibular canal in the first and second molar regions were compared. Dimensional accuracy in the second molar region was also compared. Results: With CT, the canals of the first molar regions were not identified in 11 of 19 sites; however, MRI identified the canals in all 19 sites. Using the kappa index, we found that the inter- and intraobserver identification reliabilities (0.84 and 0.87, respectively) were excellent, especially for MRI. Dimensional positioning of the canal in the second molar region was almost the same with MRI as with CT. Conclusions: MRI is an alternative method in diagnosis prior to dental implant treatment in the mandibular molar region. [source]

Spread and current potential distribution of an alien grass, Eragrostis lehmanniana Nees, in the southwestern USA: comparing historical data and ecological niche models

DIVERSITY AND DISTRIBUTIONS, Issue 5 2006
Heather Schussman
ABSTRACT The potential distribution of alien species in a novel habitat often is difficult to predict because factors limiting species distributions may be unique to the new locale. Eragrostis lehmanniana is a perennial grass purposely introduced from South Africa to Arizona, USA in the 1930s; by the 1980s, it had doubled its extent. Based on environmental characteristics associated with its introduced and native range, researchers believed that E. lehmanniana had reached the limits of its distribution by the early 1990s. We collected data on E. lehmanniana locations from various land management agencies throughout Arizona and western New Mexico and found new records that indicate that E. lehmanniana has continued to spread. Also, we employed two modelling techniques to determine the current potential distribution and to re-investigate several environmental variables related to distribution. Precipitation and temperature regimes similar to those indicated by past research were the most important variables influencing model output. The potential distribution of E. lehmanniana mapped by both models was 71,843 km2 and covers a large portion of southeastern and central Arizona. Logistic regression (LR) predicted a potential distribution of E. lehmanniana more similar to this species current distribution than GARP based on average temperature, precipitation, and grassland species composition and recorded occurrences. Results of a cross-validation assessment and extrinsic testing showed that the LR model performed as well or better than GARP based on sensitivity, specificity, and kappa indices. [source]