Likelihood Of False Positives Research Articles

A simple checklist, that is all it takes: a cluster randomized controlled field trial on improving the treatment of suspected terrorists by the police

ObjectivesWhen it comes to interviewing suspected terrorists, global evidence points to harsh interrogation procedures, despite the likelihood of false positives. How can the state maintain an effective counterterrorism policy while simultaneously protecting civil rights? Until now, the shroud of secrecy of “national security” practices has thwarted attempts by researchers to test apparatuses that engender fair interrogation procedures. The present study aims to test one approach: the use of a “procedural justice checklist” (PJ Checklist) in interviews of suspected terrorists by counterterrorism police officers in port settings.MethodsUsing a clustered randomized controlled field test in a European democracy, we measure the effect of implementing Procedural Justice (PJ) Checklists in counterterrorism police settings. With 65 teams of officers randomly-assigned into treatment and control conditions, we compare post-interrogation surveys of suspects (n = 1418) on perceptions of legitimacy; obligations to obey the law; willingness to cooperate with the police; effectiveness of counterterrorism measures; distributive justice; feelings of social resistance to the state; and PJ. A series of multi-level linear, logistic, and ordered logit regression models are used to estimate the treatment effect, with Hedges’ g and odds ratios used for effect sizes.ResultsWhen compared with control conditions, implementing a policy of PJ Checklist causes statistically significant and large enhancement in all measured dimensions, including the willingness of suspects to obey the law (g = 1.022 [0.905, 1.138]), to cooperate with the police (g = 1.118 [0.999, 1.238]), distributive justice (g = 0.993 [0.880, 1.106]), effectiveness (g = 1.077 [0.959, 1.195]), procedural justice (g = 1.044 [0.930, 1.158]), and feelings of resistance towards the state (g = − 0.370 [− 0.259, − 0.482]).ConclusionsPJ checklists offer a simple, scalable means of improving how state agents interact with terrorism suspects. The police can use what is evidently a cost-effective tool to enhance legitimacy and cooperation with the police, even in a counterterrorism environment.

Evaluation of Cytochrome P450 Selectivity for Hydralazine as an Aldehyde Oxidase Inhibitor for Reaction Phenotyping

Hydralazine has been reported as a selective mechanism-based inactivator of aldehyde oxidase (AO) and it is widely used in the pharmaceutical industry for reaction phenotyping to estimate fraction metabolized by AO and to identify AO substrates. In this study, however, hydralazine was found to inhibit CYP1A2, 2B6, 2D6, and 3A in human suspension hepatocytes under reaction phenotyping assay conditions, at concentrations that chemically knocked out most of the AO activities (≥50 μM). Furthermore, hydralazine is a time-dependent inhibitor of CYP1A2. Based on these findings, precautions need to be taken when using hydralazine as an AO inhibitor for in vitro studies because fraction metabolized by AO is likely to be overestimated and the likelihood of false positives in identifying AO substrates increases.

Breathe Easy EDA: A MATLAB toolbox for psychophysiology data management, cleaning, and analysis.

Electrodermal activity (EDA) recordings are widely used in experimental psychology to measure skin conductance responses (SCRs) that reflect sympathetic nervous system arousal. However, irregular respiration patterns and deep breaths can cause EDA fluctuations that are difficult to distinguish from genuine arousal-related SCRs, presenting a methodological challenge that increases the likelihood of false positives in SCR analyses. Thus, it is crucial to identify respiration-related artifacts in EDA data. Here we developed a novel and freely distributed MATLAB toolbox, Breathe Easy EDA (BEEDA). BEEDA is a flexible toolbox that facilitates EDA visual inspection, allowing users to identify and eliminate respiration artifacts. BEEDA further includes functionality for EDA data analyses (measuring tonic and phasic EDA components) and reliability analyses for artifact identification. The toolbox is suitable for any experiment recording both EDA and respiration data, and flexibly adjusts to experiment-specific parameters (e.g., trial structure and analysis parameters).

Cancer detection between peripheral zone and transitional zone targeted biopsies: Preliminary results from a prospective cohort of men undergoing MRI-US fusion biopsy.

56 Background: Multiparametric MRI has emerged as a popular imaging modality to localize prostate cancer. Nevertheless, interpretation of MRI is subjective, with concerns for false positives, particularly in the transitional zone (TZ), where hyperplastic changes may be confused for suspicion of cancer. We analyzed a prospective cohort of men undergoing MRI-US fusion biopsy and compared cancer detection rate between lesions seen in the peripheral zone (PZ) and the TZ. Methods: 133 men with elevated PSA or positive DRE underwent MRI-US fusion biopsy with average of 2 cores taken per target for the detection of prostate cancer between October 2014 and July 2015. Each targeted lesion in the PZ and TZ was previously classified by radiologists according to the MRI PI-RADS score and grouped according to their level of suspicion as probably benign (1-2), indeterminate (3) or probably malignant (4-5). Histopathology from targeted cores were categorized as no cancer, non-significant cancer (Gleason 6) and significant cancer (Gleason ≥ 7). We compared the cancer detection rates between lesions in PZ and TZ lesions, based on PI-RADS score. Results: We identified 143 lesions in the PZ and 82 lesions in the TZ. Among lesions found in the TZ, 57.3% were reported as probably malignant, compared to 44.7% of lesions seen in the PZ. Cancer was diagnosed in 23% of the lesions in the PZ, compared to only in 9.7% in the TZ (p<0.01). With respect to significant cancer there was a trend towards higher detection of significant cancer in the PZ (13.29% vs. 6.10% p=0.12) compared to TZ. Furthermore, lesions in the PZ with a PI-RADS score > 4 were associated with a three-fold increase in the odds of detecting cancer compared to lesions with PI-RADS < 4 (OR 3.08; CI 95% 1.29 – 7.31, p<0.011), whereas in the TZ there was no increased risk of cancer with higher PI-RADS scores (OR 1.0 CI 95% 0.20 – 4.84, p<1.0). Conclusions: To our knowledge this is the first study to address a concern regarding an increased likelihood of false positives when reporting the presence and aggressiveness of cancer in the TZ versus the PZ. This may lead to unnecessary biopsies in men undergoing MRI of the prostate.

Correlation of Magnocellular Function with Measurements of Reading in Children

Purpose: Children with reading disability frequently exhibit reduced sensitivity to motion, as assessed by coherent motion thresholds (CMT) and critical flicker frequency (CFF). A retrospective analysis was conducted to evaluate whether there was a correlation between reading fluency as measured by the Test of Silent Word Reading Fluency (TOSWRF), reading rate (as measured with the Visagraph II Eye Movement System), and pseudoword decoding (as measured with the pseudoword decoding subtest of the Wechsler Intelligence Achievement Test, WIAT-II), and these two visual motion sensitivity tests. Methods: 68 children between the ages of 7-16 years presented to the principal investigator’s optometric practice for a vision therapy evaluation between June 1st 2010 and March 31st 2011. As part of the standard protocol for vision therapy evaluations, they were assessed using the CMT, CFF, TOSWRF, WIAT-II (pseudoword decoding subtest), and Visagraph II. The patients were divided into reading ability groups based on the published recommendations from the TOSWRF manual. Individuals at the 25% or below level were labeled as poor fluency, individuals in the 26th to 74th% level were labeled average fluency, and those in the 75% or higher level were labeled as good fluency. Results: Pearson correlations were computed between the dependent variables revealing several important relationships: Fluency (TOSWRF) correlated significantly with all of the dependent measures selected for study. Of these measures, the WIAT-II subtest score correlated the most strongly at a moderate level (r = +0.569). Reading rate (Visagraph II) was the next strongest correlate of fluency, with changes in rate accounting for 26.5% of the variance in fluency. The variables of CMT and CFF were combined with rate in two follow-up, logistic regressions to determine whether their inclusion added to the classification accuracy of rate. Both variables improved the specificity of rate, which has a high likelihood of false positives. CMT maintained the sensitivity of rate while boosting specificity, whereas CFF caused a decline in the sensitivity of rate while greatly improving specificity. Reading rate with CFF and with CMT both had an overall accurate prediction of fluency of 84%. Conclusions: Silent word reading fluency correlated with CMT, CFF, reading rate, and WIAT-2. Combining reading rate with a motion sensitivity test (either CMT or CFF) maintained good sensitivity, while greatly improving specificity. Clinicians should consider adding a motion sensitivity test to the Visagraph II reading rate assessment when evaluating school-age children who may be at risk for reading fluency deficits.

P3-07-45: Role of SPECT-CT in Detecting Sentinel Lymph Nodes in Patients with Ipsilateral Breast Cancer Recurrence and Previous Axillary Lymph Node Dissection.

Abstract Background: Use of sentinel lymph node dissection in patients with ipsilateral breast cancer recurrence and a previous axillary lymph node dissection (ALND) is still controversial. Although previous reports have showed extra-axillary drainage in 40–60% of patients, the clinical significance of this drainage is unknown. SPECT-CT may help to localize aberrant sentinel nodes. Material and Methods: Between 2008 and 2011, SLN were performed in 25 patients with ipsilateral breast cancer recurrence and previous ALND. The day before surgery 99Tc nanocolloid was injected retroareolar in the affected breast and injected intratumorally when the recurrence was after a mastectomy. Linfoscintigraphy was obtained in all patients and a SPECT-CT was performed in all cases even when planar images showed no drainage. During surgery, the sentinel node was identified using a gamma probe. During the procedure the surgeon decided to remove the sentinel node if it was considered technically feasible. The project was IRB approved and all patients signed an informed consent. Results: Records from the previous ALND showed 9 patients with positive axillary nodes with a mean of 19 (range 10–35) lymph nodes excised. Twenty four patients had undergone a lumpectomy and 1 patient a mastectomy. After the injection, the SPECT-CT showed at least one hot spot in 20 patients, with a mean of 1.8 hot spots (range 0–5). Hot spots on SPECT-CT were located as follows: in 10 patients axillary, 1 subclavicular, 7 internal mammary, 1 intramammary, 1 mediastinic and 7 patients had a contralateral axillary hot spot. In 4 patients we don't found any hot spot on SPECT-CT. After excising 2 axillary nodes and 1 intrammary node in 3 patients, the pathologist didn't identify any lymph node in the hot spot removed. This are considered as false positives (15%). In 4 patients although hot spots were identified, sentinel node dissection wasn't performed because it was arguable the benefit for the patients taking into account the location and number of hot spots. All this 4 patients are free of disease and any of them have developed recurrences. In 14 (56%) patients all the sentinel nodes were identified and removed. Three (3/14 = 21%) patients had positive sentinel nodes (1 in the ipsilateral axilla, 1 internal mammary and 1 in the contralateral axillary). One patient had 2 positive contralateral axillary sentinel nodes so an ALND was performed with no additional positive nodes. No surgical complications were observed. Conclusions: In patients who had a previous ALND who develop a breast cancer recurrence, the SPTC-CT might show the exact location of aberrant hot spots but, some of the identified as hot spots may not be lymph nodes. We must consider the exact location of the hot spot and the likelihood of false positives to avoid additional morbidity on the procedure. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-07-45.

The effect of minor allele frequency on the likelihood of obtaining false positives

Determining the most promising single-nucleotide polymorphisms (SNPs) presents a challenge in genome-wide association studies, when hundreds of thousands of association tests are conducted. The power to detect genetic effects is dependent on minor allele frequency (MAF), and genome-wide association studies SNP arrays include SNPs with a wide distribution of MAFs. Therefore, it is critical to understand MAF's effect on the false positive rate.Data from the Framingham Heart Study simulated data (Problem 3, with answers) was used to examine the effects of varying MAFs on the likelihood of false positives. Replication set 1 was used to generate 1 million permutations of case/control status in unrelated individuals. Logistic regression was used to test for the association between each SNP and myocardial infarction using an additive model. We report the number of "significant" tests by MAF at α = 10-4, 10-5, and 10-6.Common SNPs exhibited fewer false positives than expected. At α = 10-4, SNPs with MAF 25% and 50% resulted in 69.2 [95%CI: 62.8-75.6] and 70.8 [95%CI: 61.3-80.4] false positives, respectively, compared to 100 expected. Rare SNPs exhibited more variability but did not show more false-positive results than expected by chance. However, at α = 10-4, MAF = 5% exhibited significantly more false positives (105.5 [95%CI: 81-130.1]) than MAF = 25% and 50%. Similar results were seen at the other alpha values.These results suggest that removal of low MAF SNPs from analysis due to concerns about inflated false-positive results may not be appropriate.

Cumulative Incidence of False-Positive Results in Repeated, Multimodal Cancer Screening

Multiple cancer screening tests have been advocated for the general population; however, clinicians and patients are not always well-informed of screening burdens. We sought to determine the cumulative risk of a false-positive screening result and the resulting risk of a diagnostic procedure for an individual participating in a multimodal cancer screening program. Data were analyzed from the intervention arm of the ongoing Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial, a randomized controlled trial to determine the effects of prostate, lung, colorectal, and ovarian cancer screening on disease-specific mortality. The 68,436 participants, aged 55 to 74 years, were randomized to screening or usual care. Women received serial serum tests to detect cancer antigen 125 (CA-125), transvaginal sonograms, posteroanterior-view chest radiographs, and flexible sigmoidoscopies. Men received serial chest radiographs, flexible sigmoidoscopies, digital rectal examinations, and serum prostate-specific antigen tests. Fourteen screening examinations for each sex were possible during the 3-year screening period. After 14 tests, the cumulative risk of having at least 1 false-positive screening test is 60.4% (95% CI, 59.8%-61.0%) for men, and 48.8% (95% CI, 48.1%-49.4%) for women. The cumulative risk after 14 tests of undergoing an invasive diagnostic procedure prompted by a false-positive test is 28.5% (CI, 27.8%-29.3%) for men and 22.1% (95% CI, 21.4%-22.7%) for women. For an individual in a multimodal cancer screening trial, the risk of a false-positive finding is about 50% or greater by the 14th test. Physicians should educate patients about the likelihood of false positives and resulting diagnostic interventions when counseling about cancer screening.

Assessing Viability of Prevariety Germplasm of Native Coreopsis Species

Dormancy issues and lack of approved protocols have led to increasing use of the pregermination tetrazolium test to assess whether seeds of premium-priced, prevariety germplasm of native wildflower species are living and have the potential to germinate and develop normally under field conditions, that is, whether seeds are viable. A major concern is the limited amount of industrywide training on how to conduct and interpret results of tetrazolium (TZ) tests for the multitude of native species. Precise methods that yield uniform results are especially critical for testing of prevariety germplasm of native species given their high value and economic consequences of inaccurate test results. In preliminary work, we observed that embryos extracted from intact seeds of native Coreopsis species subjected to TZ testing were viable if they were turgid and appeared normal and were stained pink, red, or were pure white with or without the radicle tip stained pink to red. In this study, we conducted an in-depth analysis of TZ testing of intact seeds of prevariety germplasm of four native Coreopsis species to: 1) verify our preliminary conclusions; and 2) to determine if staining could be improved by preconditioning or gibberellic acid (GA3) because relatively low percentages of embryos of intact seeds stained pink or red. In addition, we evaluated two other methods to assess viability: the excised embryo test and emergence tests in soil and a soilless medium under ambient conditions. We confirmed that embryos extracted from intact seeds subjected to TZ testing were viable provided that embryos were turgid and appeared normal and were stained pink, red, or were pure white ± a pink to red radicle tip. Embryo staining was not consistently improved by moist preconditioning or GA3. Results of pregermination TZ tests of intact seeds and/or germination plus postgermination TZ tests of intact, nongerminated seeds were not consistently accurate and/or uniform across all species and seed lots, issues usually encountered in seed lots that were relatively dormant or of poor quality, and in postgermination TZ testing of seed lots with relatively low dormancy. Moreover, these issues are likely to be encountered even with standard TZ testing protocols given the widely accepted challenges of accurately interpreting TZ tests of native species in general. The most precise, uniform method of assessing viability was the excised embryo germination test because all viable seeds germinated, results were easy to interpret so the likelihood of false-positives or -negatives was nil, and results were very uniform across replications. Emergence tests under ambient conditions substantially underestimated viability. In summary, the high cost of prevariety germplasm seeds of native Coreopsis species, inherent genetic and phenotypic variability, and unknown dormancy characteristics warrant the use of the embryo excision test for determining viability and for increased sample sizes, especially for any tests involving TZ.

Safe systems of work are needed for the diagnosis of occupational mental illness

Occupational mental illness is now the most commonly reported illness to the national surveillance scheme, Occupational Physician Reporting Activity, of work related illness [1]. Its diagnosis is problematic as it involves recognizing a pattern of subjective symptoms in a patient that can be causally attributed to work rather than to personal vulnerabilities. As with most psychiatric illness there is no objective test to confirm the diagnosis. The difficulty of verifying the existence of a stressful working environment and of associating it with a particular occupation or job have been given as reasons for not making occupational mental illness a Prescribed Industrial Injury [2]. Neither is it recognized by the Health and Safety Executive in the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations. This contrasts with personal injury litigation or injury awards for certain pension schemes that recognize occupational mental illness as an injury and require doctors to give an opinion about causality. Characteristics of workplaces that are hazardous for mental health have been identified from a variety of observational studies and include those where there are high demands on employees, a lack of control over the way the work is done, a lack of social support, an imbalance between effort and reward, job dissatisfaction, a hostile working environment or culture such as bullying or where there is job insecurity due to restructuring or external inspections [3–7]. Less commonly operational aspects of the job are reported as sources of stress but these tend to be in extreme circumstances where there is a risk of personal harm. The importance of obtaining information independent of the patient (known epidemiologically as triangulation) may be helpful for validation purposes. Personal factors associated with mental illness need to be assessed to include a previous personal or family history of mental illness, recent stressful life events and personality traits of neuroticism [8]. An experienced occupational physician is familiar with evaluating relevant personal and workplace factors and with diagnosing common mental illnesses such as anxiety or depression. For example, the victim of unreasonable or particularly stressful working practices with anxiety specific to work or depression, but with no other relevant trigger factor and no past medical history of mental illness or neurotic personality traits, is likely to be suffering from occupational mental illness. Such patients are usually the most vulnerable in an organization and it is one of the roles of an occupational physician to support and protect these patients while simultaneously preventing similar illnesses in other workers. Unfortunately many such patients either leave or are dismissed after a prolonged period of sickness absence on the grounds of incapability. The benefit of a correct diagnosis needs to be weighed against the harm of a false one. The occurrence of several cases of occupational mental illness from one employer reduces the likelihood of false positives, provided such diagnoses have not been made negligently or there has not been a deliberate attempt to mislead the doctor. It is regrettable that in communicating the diagnosis of occupational mental illness (with the consent of the employee) to the responsible employer it may be met with an angry response to include the threat of loss of contract, a vindictive complaint or attempts to discredit the doctor’s diagnostic skills [9]. By contrast, the communication of an occupational physical illness is unlikely to be met with such a response and in some circumstances it is a statutory requirement (e.g. the Lead, Asbestos and Ionising Radiation Regulations). The reporting of occupational mental illness to the employer’s health and safety committee, or by way of an annual report from occupational health, may be met with similar resistance thereby making the integration of certain occupational health data into management statistics and Regulatory compliance problematic [10]. Alternative strategies used by occupational physicians to handle this situation include equivocation over diagnostic aetiology or writing an additional letter to management that is not seen by the patient. However, both these methods can cause the doctor to lose credibility in the eyes of the patient and by so doing he or she will be compromising their professional independence. The Health Correspondence to: Department of Occupational Health, Dudley NHS PCT, Health Centre, Cross Street, Dudley, DY1 1RN, UK. Tel: +44 1384 366 423, fax: +44 1384 366 422; e-mail: jon.poole@dudley.nhs.uk

Information derived from sensitization test methods: test sensitivity, false positives and false negatives

Predictive toxicology tests for the prospective identification of skin-sensitizing chemicals are well known and have been used for many years. However, of these, only the local lymph node assay (LLNA) has actually undergone formal independent assessment to determine the accuracy of the predictions, particularly with respect to the likelihood of false positives and false negatives. Often, efforts to increase the sensitivity of a test (reducing false negatives) tend to increase the number of false positives. In this short review, these issues are discussed in particular relation to the 3 predictive tests available in regulatory toxicology, the guinea-pig maximization test, the occluded patch test of Buehler and the LLNA. A key perspective is that no predictive test is without limitations; having a good appreciation of these limitations is necessary for making the best use of the information derived from these methods.

CT Screening — whole-body and targeted

At present, the Australasian College of Physical Scientists and Engineers in Medicine does not support the practice of self-referred whole-body CT screening of asymptomatic patients because: The procedure involves a non-trivial radiation dose, which assumes even greater significance in the context of an ongoing screening programme; There is a high likelihood of false positives requiring further intervention with its attendant risks; and There is no proven evidence to date that early detection of life-threatening disease by CT has a significant positive effect on patient outcome. The ACPSEM will continue to monitor scientific studies concerning this procedure.

Children's Understanding of the Relation between Delayed Video Representation and Current Reality: A Test for Self-Awareness?

This study investigated whether children's ability to recognize themselves in delayed video feedback indicates changes in self-awareness (Povinelli, Landau, & Perilloux, 1996,Child Development,67, 1540–1554). Children were presented with 3-min-old videos of themselves to test whether they would investigate the current state of affairs upon seeing a surprising element in the video. In one condition, a sticker had been covertly placed into the child's hair, and in another an object had been hidden in a box. Both conditions proved equally difficult and performance correlated. Four-year-olds performed better than 3-year-olds, and children who failed the tasks retrieved the “surprise” item when presented with a mirror. There was no evidence to suggest that children's difficulties were due to immature metarepresentational thinking, lack of experience, problems with the questions, or problems appreciating the correspondence between image and referent. Yet, the parallel results in both conditions and the likelihood of false positives and false negatives indicate that the video test in its present form may not be a valid measure of differences in self-awareness.

How useful are routine chest x-rays of preoperative patients at risk for postoperative chest disease?

The authors studied the value of routine chest x-rays in the management of patients admitted for vascular surgery, a population likely to have comorbid chest disease. Patient records from 341 admissions were reviewed to determine the relationship between chest x-ray results and postoperative chest complications. Patients who had major abnormalities had a 40% postoperative complication rate, compared with 9% for those with normal x-rays; but only 13% of the complications occurred in patients with major abnormalities. Nine patients had x-ray findings that led to clinical action: three with potentially beneficial management changes (congestive heart failure in 2, fibrosis in 1) and six with potentially detrimental clinical action (false diagnosis of tuberculosis in 2, false diagnosis of nodules in 2, falsely normal chest x-ray in 2). None of 50 surgical cancellations occurred as a result of an abnormal x-ray. All the beneficial effects attributable to preoperative chest x-rays accrued to patients who had clinical evidence of chest disease. The authors conclude that routine chest x-rays were not helpful in improving patient outcomes. They recommend ordering preoperative chest x-rays based on clinical indications so that the likelihood of false positives and false negatives and their associated detrimental effects can be minimized.