Almost stochastic dominance has been receiving a great amount of attention in the financial and economic literatures. In this paper, we characterize the properties of almost first-order stochastic dominance (AFSD) via distorted expectations and investigate the conditions under which AFSD is preserved under a distortion transform. The main results are also applied to establish stochastic comparisons of order statistics and receiver operating characteristic curves via AFSD.

Glyphosate and paraquat herbicide drift injury to crops may substantially reduce growth or yield. Determining the type and degree of injury is of importance to a producer. This research was conducted to determine whether remote sensing could be used to identify and quantify herbicide injury to crops. Soybean and corn plants were grown in 3.8-L pots to the five- to seven-leaf stage, at which time, applications of nonselective herbicides were made. Visual injury estimates were made, and hyperspectral reflectance data were recorded 1, 4, and 7 d after application (DAA). Several analysis techniques including multiple indices, signature amplitude (SA) with spectral bands as features, and wavelet analysis were used to distinguish between herbicide-treated and nontreated plants. Classification accuracy using SA analysis of paraquat injury on soybean was better than 75% for both 1/2- and 1/8× rates at 1, 4, and 7 DAA. Classification accuracy of paraquat injury on corn was better than 72% for the 1/2× rate at 1, 4, and 7 DAA. These data suggest that hyperspectral reflectance may be used to distinguish between healthy plants and injured plants to which herbicides have been applied; however, the classification accuracies remained at 75% or higher only when the higher rates of herbicide were applied. Applications of a 1/2× rate of glyphosate produced 55 to 81% soybean injury and 20 to 50% corn injury 4 and 7 DAA, respectively. However, using SA analysis, the moderately injured plants were indistinguishable from the uninjured controls, as represented by the low classification accuracies at the 1/8-, 1/32-, and 1/64× rates. The most promising technique for identifying drift injury was wavelet analysis, which successfully distinguished between corn plants treated with either the 1/8- or the 1/2× rates of paraquat compared with the nontreated corn plants better than 92% 1, 4, and 7 DAA. These analysis techniques, once tested and validated on field scale data, may help determine the extent and the degree of herbicide drift for making appropriate and, more importantly, timely management decisions.

Two experiments, one focusing on preemergence (PRE) herbicides and the other on postemergence (POST) herbicides, were conducted and repeated in time to examine the utility of hyperspectral remote sensing data for discriminating common cocklebur, hemp sesbania, pitted morningglory, sicklepod, and soybean after PRE and POST herbicide application. Discriminant models were created from combinations of multiple indices. The model created from the second experimental run's data set and validated on the first experimental run's data provided an average of 97% correct classification of soybean and an overall average classification accuracy of 65% for all species. These data suggest that these models are relatively robust and could potentially be used across a wide range of herbicide applications in field scenarios. From the data set pooled across time and experiment types, a single discriminant model was created with multiple indices that discriminated soybean from weeds 88%, on average, regardless of herbicide, rate, or species. Signature amplitudes, an additional classification technique, produced variable results with respect to discriminating soybean from weeds after herbicide application and discriminating between controls and plants to which herbicides were applied; thus, this was not an adequate classification technique.

Naming or word-finding tasks are a mainstay of the typical neuropsychological evaluation, particularly with older adults. However, many older adults have significant visual impairment and there are currently no such word-finding tasks developed for use with older visually impaired populations. This study presents a verbal, non-visual measure of word-finding for use in the evaluation of older adults with possible dysnomia. Stimuli were chosen based on their frequency of usage in everyday spoken language. A 60-item scale was created and given to 131 older Veterans. Rasch analyses were conducted and differential item functioning assessed to eliminate poorly-performing items. The final 55-item scale had a coefficient alpha of 0.84 and correlated with the Neuropsychological Assessment Battery Naming test, r=0.84, p<.01, Delis-Kaplan Executive Function System (D-KEFS) Category Fluency, r=0.45, p<.01, and the D-KEFS Letter Fluency, r=0.40, p<.01. ROC analyses found the measure to have sensitivity of 79% and specificity of 85% for detecting dysnomia. Patients with dysnomia performed worse on the measure than patients with intact word-finding, t(84)=8.2, p<.001. Patients with no cognitive impairment performed significantly better than patients with mild cognitive impairment, who performed significantly better than patients with dementia. This new measure shows promise in the neuropsychological evaluation of word-finding ability in older adults with or without visual impairment. Future directions include the development of a shorter version and the generation of additional normative data. (JINS, 2015, 21, 1–10)

A meta-analysis was conducted to reach a pooled estimate of the diagnostic accuracy of the SCOFF. The 15 selected studies represented a total of 882 cases and 4350 controls. The main criterion for inclusion was that the primary study had provided diagnostic classification with both a diagnostic reference and with the SCOFF (with five items and a cut-off point of two). The pooled estimates were .80 (sensitivity) and .93 (specificity). The moderator variables gender and type of measure for the diagnostic reference (interview versus psychometric tests) account for part of the observed variability. For diagnostic references based on interviews the estimate of the efficacy improves significantly. For the studies that match this criterion the sensitivity is .882 and the specificity .925 (diagnostic odds ratio, 92.19). The main conclusion was that the five questions of the SCOFF constitute a very useful screening tool, in several languages; it is highly recommended for screening purposes.

Objective: The aim of this study was to present a clear process of synthesizing test accuracy data when conducting economic evaluations of diagnostic tests for health technology assessment (HTA) assessors and health economists.

Methods: We appraised the methods advocated for using diagnostic test accuracy data in economic evaluations. We used a case study of fetal anemia in which data from a screening test are used in combination with a confirmatory test.

Results: We developed a step-by-step guide and consider two scenarios: when data on test accuracy from several studies are based on (i) the same test threshold for positivity and (ii) different test thresholds.

Conclusions: We conclude that each approach has its strengths and limitations. We show that the optimal operating point of the test should be identified to determine the true cost-effectiveness of the test. We advocate that these issues require a multidisciplinary team of health economists, decision modelers and statisticians.

Risk assessment is now regarded as a necessary competence in psychiatry. The area under the curve (AUC) statistic of the receiver operating characteristic curve is increasingly offered as the main evidence for accuracy of risk assessment instruments. But, even a highly statistically significant AUC is of limited value in clinical practice.

Objective: This article outlines basic methods for quantifying reproducibility and responsiveness of evaluative outcome measures.

Methods: The background noise in stable patients provides the desired information to quantify the reproducibility. From this, the smallest real difference (SRD) for longitudinal differences can be derived. We propose to use the SRD to define responsiveness: from all patients who change according to an external criterion, we take the percentage that changes at least SRD on the outcome measure. A more complete picture of the responsiveness of the outcome measure arises when the receiver operating characteristic (ROC) is constructed, corresponding to all possible cut-off change scores. The proposed methods are illustrated with an empirical example.

Results: In the illustration the methods appeared to be very useful and complemented each other. We could evaluate whether the observed change score was larger than that expected due to chance. With the methods it was possible to evaluate both the ability of an instrument to detect change if there is a real change in health status (sensitivity to change) and the ability to detect absence of change if there is no real change (specificity to change).

Conclusion: We presented the use of SRDs and ROC curves for quantifying reproducibility and responsiveness. We started with the basic notions and arrived at methods that are both understandable and useful.