Can a novel web-based computer test predict poor simulated driving performance? A pilot study with healthy and cognitive-impaired participants

BACKGROUND Driving a car is a complex instrumental activity of daily living and driving performance is very sensitive to cognitive impairment. The assessment of driving-relevant cognition in older drivers is challenging and requires reliable and valid tests with good sensitivity and specificity to predict safe driving. Driving simulators can be used to test fitness to drive. Several studies have found strong correlation between driving simulator performance and on-the-road driving. However, access to driving simulators is restricted to specialists and simulators are too expensive, large, and complex to allow easy access to older drivers or physicians advising them. An easily accessible, Web-based, cognitive screening test could offer a solution to this problem. The World Wide Web allows easy dissemination of the test software and implementation of the scoring algorithm on a central server, allowing generation of a dynamically growing database with normative values and ensures that all users have access to the same up-to-date normative values. OBJECTIVE In this pilot study, we present the novel Web-based Bern Cognitive Screening Test (wBCST) and investigate whether it can predict poor simulated driving performance in healthy and cognitive-impaired participants. METHODS The wBCST performance and simulated driving performance have been analyzed in 26 healthy younger and 44 healthy older participants as well as in 10 older participants with cognitive impairment. Correlations between the two tests were calculated. Also, simulated driving performance was used to group the participants into good performers (n=70) and poor performers (n=10). A receiver-operating characteristic analysis was calculated to determine sensitivity and specificity of the wBCST in predicting simulated driving performance. RESULTS The mean wBCST score of the participants with poor simulated driving performance was reduced by 52%, compared to participants with good simulated driving performance (P<.001). The area under the receiver-operating characteristic curve was 0.80 with a 95% confidence interval 0.68-0.92. CONCLUSIONS When selecting a 75% test score as the cutoff, the novel test has 83% sensitivity, 70% specificity, and 81% efficiency, which are good values for a screening test. Overall, in this pilot study, the novel Web-based computer test appears to be a promising tool for supporting clinicians in fitness-to-drive assessments of older drivers. The Web-based distribution and scoring on a central computer will facilitate further evaluation of the novel test setup. We expect that in the near future, Web-based computer tests will become a valid and reliable tool for clinicians, for example, when assessing fitness to drive in older drivers.

Economic efficiency analysis of different strategies to control post-weaning multi-systemic wasting syndrome and porcine circovirus type 2 subclinical infection in 3-weekly batch system farms.

The study assessed the economic efficiency of different strategies for the control of post-weaning multi-systemic wasting syndrome (PMWS) and porcine circovirus type 2 subclinical infection (PCV2SI), which have a major economic impact on the pig farming industry worldwide. The control strategies investigated consisted on the combination of up to 5 different control measures. The control measures considered were: (1) PCV2 vaccination of piglets (vac); (2) ensuring age adjusted diet for growers (diets); (3) reduction of stocking density (stock); (4) improvement of biosecurity measures (bios); and (5) total depopulation and repopulation of the farm for the elimination of other major pathogens (DPRP). A model was developed to simulate 5 years production of a pig farm with a 3-weekly batch system and with 100 sows. A PMWS/PCV2SI disease and economic model, based on PMWS severity scores, was linked to the production model in order to assess disease losses. This PMWS severity scores depends on the combination post-weaning mortality, PMWS morbidity in younger pigs and proportion of PCV2 infected pigs observed on farms. The economic analysis investigated eleven different farm scenarios, depending on the number of risk factors present before the intervention. For each strategy, an investment appraisal assessed the extra costs and benefits of reducing a given PMWS severity score to the average score of a slightly affected farm. The net present value obtained for each strategy was then multiplied by the corresponding probability of success to obtain an expected value. A stochastic simulation was performed to account for uncertainty and variability. For moderately affected farms PCV2 vaccination alone was the most cost-efficient strategy, but for highly affected farms it was either PCV2 vaccination alone or in combination with biosecurity measures, with the marginal profitability between 'vac' and 'vac+bios' being small. Other strategies such as 'diets', 'vac+diets' and 'bios+diets' were frequently identified as the second or third best strategy. The mean expected values of the best strategy for a moderately and a highly affected farm were £14,739 and £57,648 after 5 years, respectively. This is the first study to compare economic efficiency of control strategies for PMWS and PCV2SI. The results demonstrate the economic value of PCV2 vaccination, and highlight that on highly affected farms biosecurity measures are required to achieve optimal profitability. The model developed has potential as a farm-level decision support tool for the control of this economically important syndrome.

A Bootstrap Test for the Probability of Ruin in the Compound Poisson Risk Process

In this article we propose a bootstrap test for the probability of ruin in the compound Poisson risk process. We adopt the P-value approach, which leads to a more complete assessment of the underlying risk than the probability of ruin alone. We provide second-order accurate P-values for this testing problem and consider both parametric and nonparametric estimators of the individual claim amount distribution. Simulation studies show that the suggested bootstrap P-values are very accurate and outperform their analogues based on the asymptotic normal approximation.

Efficiency and safety of bosentan in child C cirrhosis with portopulmonary hypertension and renal insufficiency

Bosentan has lately been described as a successful therapeutic agent for portopulmonary hypertension consecutive to child A cirrhosis. This is the first report of the effect of this substance with advanced liver cirrhosis (child C) and renal insufficiency. Low doses of bosentan (initially twice 31.25 mg/day and then 62.5 mg/day) increased cardiac output and allowed correction of renal insufficiency; it allowed one to stop the requirement of oxygen and not only improved the 6-min walking test by more than 400 m, but also decreased the severity of the liver cirrhosis to child B stadium. This suggests that patients, who would be excluded from a liver transplantation program because of their portopulmonary hypertension, could profit from a careful therapy with bosentan.

Accuracy of B-type natriuretic peptide tests to exclude congestive heart failure: systematic review of test accuracy studies

BACKGROUND: Congestive heart failure (CHF) is a major public health problem. The use of B-type natriuretic peptide (BNP) tests shows promising diagnostic accuracy. Herein, we summarize the evidence on the accuracy of BNP tests in the diagnosis of CHF and compare the performance of rapid enzyme-linked immunosorbent assay (ELISA) and standard radioimmunosorbent assay (RIA) tests. METHODS: We searched electronic databases and the reference lists of included studies, and we contacted experts. Data were extracted on the study population, the type of test used, and methods. Receiver operating characteristic (ROC) plots and summary ROC curves were produced and negative likelihood ratios pooled. Random-effect meta-analysis and metaregression were used to combine data and explore sources of between-study heterogeneity. RESULTS: Nineteen studies describing 22 patient populations (9 ELISA and 13 RIA) and 9093 patients were included. The diagnosis of CHF was verified by echocardiography, radionuclide scan, or echocardiography combined with clinical criteria. The pooled negative likelihood ratio overall from random-effect meta-analysis was 0.18 (95% confidence interval [CI], 0.13-0.23). It was lower for the ELISA test (0.12; 95% CI, 0.09-0.16) than for the RIA test (0.23; 95% CI, 0.16-0.32). For a pretest probability of 20%, which is typical for patients with suspected CHF in primary care, a negative result of the ELISA test would produce a posttest probability of 2.9%; a negative RIA test, a posttest probability of 5.4%. CONCLUSIONS: The use of BNP tests to rule out CHF in primary care settings could reduce demand for echocardiography. The advantages of rapid ELISA tests need to be balanced against their higher cost.

Treatment of hyperactive children: increased efficiency through modifications of homeopathic diagnostic procedure

BACKGROUND: The rigorous test to which homeopathy was subject in our recent double-blind clinical trail of homeopathic treatment of attention deficit hyperactivity disorder (ADHD) necessitated optimized treatment meeting the highest standards. METHODS: Optimization was performed in three steps: (1) In successfully treated children, prescriptions leading to an insufficient response were analysed by a general questionnaire to identify unreliable symptoms. (2) Polarity analysis, a further development of Bönninghausen's concept of contraindications, was introduced in response to the frequently one-sided symptoms. This enabled us to use few but specific symptoms to identify the medicine whose genius symptoms exhibit the closest match to the patient's characteristic symptoms. (3) We investigated the influence of the primary perception symptoms on the result of the repertorization. Perception symptoms are not normally recorded during a patient interview even though they are among the most reliable facts related by the patients. At the same time we were able to improve the continuity of improvement of ADHD symptoms using liquid Q-potencies. RESULTS: Introducing the questionnaire, polarity analysis, and including perception symptoms, lead to an improvement in the success rate of the first prescription from 21% to 54%, of the fifth prescription from 68% to 84%.

Avoidant coping partially mediates the relationship between patient problem behaviors and depressive symptoms in spousal Alzheimer caregivers

OBJECTIVE: Caring for a loved one with Alzheimer disease is a highly stressful experience that is associated with significant depressive symptoms. Previous studies indicate a positive association between problem behaviors in patients with Alzheimer disease (e.g., repeating questions, restlessness, and agitation) and depressive symptoms in their caregivers. Moreover, the extant literature indicates a robust negative relationship between escape-avoidance coping (i.e., avoiding people, wishing the situation would go away) and psychiatric well-being. The purpose of this study was to test a mediational model of the associations between patient problem behaviors, escape-avoidance coping, and depressive symptoms in Alzheimer caregivers. METHODS: Ninety-five spousal caregivers (mean age: 72 years) completed measures assessing their loved ones' frequency of problem behaviors, escape-avoidance coping, and depressive symptoms. A mediational model was tested to determine if escape-avoidant coping partially mediated the relationship between patient problem behaviors and caregiver depressive symptoms. RESULTS: Patient problem behaviors were positively associated with escape-avoidance coping (beta = 0.38, p < 0.01) and depressive symptoms (beta = 0.26, p < 0.05). Escape-avoidance coping was positively associated with depressive symptoms (beta = 0.33, p < 0.01). In a final regression analysis, the impact of problem behaviors on depressive symptoms was less after controlling for escape-avoidance coping. Sobel's test confirmed that escape-avoidance coping significantly mediated the relationship between problem behaviors and depressive symptoms (z = 2.07, p < 0.05). CONCLUSION: Escape-avoidance coping partially mediates the association between patient problem behaviors and depressive symptoms among elderly caregivers of spouses with dementia. This finding provides a specific target for psychosocial interventions for caregivers.

Success rate and efficiency of activator treatment

In a retrospective multicentre study, the success rate and efficiency of activator treatment were analysed. All patients from two University clinics (Giessen, Germany and Berne, Switzerland) that fulfilled the selection criteria (Class II division 1 malocclusion, activator treatment, no aplasia, no extraction of permanent teeth, no syndromes, no previous orthodontic treatment except transverse maxillary expansion, full available records) were included in the study. The subject material amounted to 222 patients with a mean age of 10.6 years. Patient records, lateral head films, and dental casts were evaluated. Treatment was classified as successful if the molar relationship improved by at least half to three-fourths cusp width depending on whether or not the leeway space was used during treatment. Group comparisons were carried out using Wilcoxon two-sample and Kruskal-Wallis tests. For discrete data, chi-square analysis was used and Fisher's exact test when the sample size was small. Stepwise logistic regression was also employed. The success rate was 64 per cent in Giessen and 66 per cent in Berne. The only factor that significantly (P < 0.001) influenced treatment success was the level of co-operation. In approximately 27 per cent of the patients at both centres, the post-treatment occlusion was an 'ideal' Class I. In an additional 38 per cent of the patients, marked improvements in occlusal relationships were found. In subjects with Class II division 1 malocclusions, in which orthodontic treatment is performed by means of activators, a marked improvement of the Class II dental arch relationships can be expected in approximately 65 per cent of subjects. Activator treatment is more efficient in the late than in the early mixed dentition.

Efficiency of arthroscopic lysis and lavage for internal derangement of the temporomandibular joint correlated with Wilkes classification

OBJECTIVES: To compare the outcome of arthroscopic lysis and lavage of TMJ with internal derangement of Wilkes stages II, III, IV, and V. STUDY DESIGN: Arthroscopic lysis and lavage was performed in 45 TMJ of 39 patients with internal derangement. The cases were divided into 4 groups corresponding to Wilkes stages II, III, IV, and V. Two parameters were compared pre- and postoperatively: pain and mouth opening. Statistical significance was determined using the chi(2) test. RESULTS: Overall success rate was 86.7% (Wilkes stage II 90.9%, Wilkes stage III 92.3%, Wilkes stage IV 84.6%, Wilkes stage V 75%). There were no statistically significant differences between the success rates for Wilkes stages II, III, IV, and V. CONCLUSION: Arthroscopic lysis and lavage should be performed as a standard operation for internal derangement of the TMJ after failure of conservative treatment in all Wilkes stages.

The influence of zero value subtraction on the performance of a new laser fluorescence device for approximal caries detection

The aim of this study was to assess the influence of the zero value subtraction on the performance of laser fluorescence (LFpen) for approximal caries detection. Three areas (cuspal, middle and cervical) of both mesial and distal buccal surfaces of 78 permanent molars were assessed using both wedge-shaped (WDG) and tapered wedge-shaped (TWDG) tips. With the addition of the average, one cut-off value for each area was obtained and the performance was assessed. The areas under the receiver operating characteristics (ROC) curve, specificity, sensitivity and accuracy with and without the zero value subtraction were calculated. The McNemar test revealed a statistically significant difference for specificity at thresholds D(1), D(2) and D(3) (WDG) and D(1) and D(2) (TWDG) when the zero value subtraction was not performed. Influence of the zero value subtraction on the LFpen performance was observed for approximal caries detection. However, when modified cut-off values were used, the zero value subtraction could be eliminated.

Comparison of interferon-gamma release assay versus tuberculin skin test for tuberculosis screening in inflammatory bowel disease

OBJECTIVES: Reactivation of latent tuberculosis (TB) in inflammatory bowel disease (IBD) patients treated with antitumor necrosis factor-alpha medication is a serious problem. Currently, TB screening includes chest x-rays and a tuberculin skin test (TST). The interferon-gamma release assay (IGRA) QuantiFERON-TB Gold In-Tube (QFT-G-IT) shows better specificity for diagnosing TB than the skin test. This study evaluates the two test methods among IBD patients. METHODS: Both TST and IGRA were performed on 212 subjects (114 Crohn's disease, 44 ulcerative colitis, 10 indeterminate colitis, 44 controls). RESULTS: Eighty-one percent of IBD patients were under immunosuppressive therapy; 71% of all subjects were vaccinated with Bacille Calmette Guérin; 18% of IBD patients and 43% of controls tested positive with the skin test (P < 0.0001). Vaccinated controls tested positive more often with the skin test (52%) than did vaccinated IBD patients (23%) (P = 0.011). Significantly fewer immunosuppressed patients tested positive with the skin test than did patients not receiving therapy (P = 0.007); 8% of patients tested positive with the QFT-G-IT test (14/168) compared to 9% (4/44) of controls. Test agreement was significantly higher in the controls (P = 0.044) compared to the IBD group. CONCLUSIONS: Agreement between the two test methods is poor in IBD patients. In contrast to the QFT-G-IT test, the TST is negatively influenced by immunosuppressive medication and vaccination status, and should thus be replaced by the IGRA for TB screening in immunosuppressed patients having IBD.

Test Blueprints - Exposing Side Effects in Execution Traces to Support Writing Unit Tests

Writing unit tests for legacy systems is a key maintenance task. When writing tests for object-oriented programs, objects need to be set up and the expected effects of executing the unit under test need to be verified. If developers lack internal knowledge of a system, the task of writing tests is non-trivial. To address this problem, we propose an approach that exposes side effects detected in example runs of the system and uses these side effects to guide the developer when writing tests. We introduce a visualization called Test Blueprint, through which we identify what the required fixture is and what assertions are needed to verify the correct behavior of a unit under test. The dynamic analysis technique that underlies our approach is based on both tracing method executions and on tracking the flow of objects at runtime. To demonstrate the usefulness of our approach we present results from two case studies.

NLO thermal dilepton rate at non-zero momentum

The vector channel spectral function and the dilepton production rate from a QCD plasma at a temperature above a few hundred MeV are evaluated up to next-to-leading order (NLO) including their dependence on a non-zero momentum with respect to the heat bath. The invariant mass of the virtual photon is taken to be in the range K2 ~ (πT)2 ~ (1GeV)2, generalizing previous NLO results valid for K2 ≫ (πT)2. In the opposite regime 0 < K2 ≪ (πT)2 the loop expansion breaks down, but agrees nevertheless in order of magnitude with a previous result obtained through resummations. Ways to test the vector spectral function through comparisons with imaginary-time correlators measured on the lattice are discussed.

Cognitive inertia and the implicit association test

The authors review the implicit association test (IAT), its use in marketing, and the methodology and validity issues that surround it. They focus on a validity problem that has not been investigated previously, namely, the impact of cognitive inertia on IAT effects. Cognitive inertia refers to the difficulty in switching from one categorization rule to another, which causes IAT effects to depend on the order of administration of the two IAT blocks. In Study 1, the authors observe an IAT effect when the compatible block precedes the incompatible block but not when it follows the incompatible block. In Studies 2 and 3, the IAT effect changes its sign when the order of the blocks reverses. Cognitive inertia distorts individual IAT scores and diminishes the correlations between IAT scores and predictor variables when the block order is counterbalanced between subjects. Study 4 shows that counterbalancing the block order repeatedly within subjects can eliminate cognitive inertia effects on the individual level. The authors conclude that researchers should either interpret IAT scores at the aggregate level or, if individual IAT scores are of interest, counterbalance the block order repeatedly within subjects.