93,106 research outputs found
Accuracy of urinary human papillomavirus testing for presence of cervical HPV: systematic review and meta-analysis
This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 3.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/3.0/.Funding: This study did not receive any fundin
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Development and validation of a new glaucoma screening test using temporally modulated flicker
Purpose
Describing the psychometric characteristics and diagnostic accuracy of the Accelerator 4âAlternative ForcedâChoice Flicker Test prototype (A4FTp) for detecting chronic open angle glaucoma (COAG).
Methods
A4FTp measures temporallyâmodulated flicker thresholds in regions of the visual field with high susceptibility to glaucomatous loss. We initially evaluated its psychometric properties on 20 normals (aged 33.8 ± 8.5 years) who were tested multiple times over a period of 3 months. All subjects underwent four repetitions for shorter (T8) and longer (T12) staircase termination criteria, to determine the most suitable threshold criterion. Four randomly selected subjects underwent a total of 10 repetitions to study testâretest repeatability and learning effects. To determine its diagnostic accuracy, one eye of 40 participants with COAG and 38 normal controls were tested with the A4FTp in comparison with the Frequency Doubling Technology (FDT; C20â5 programme) and iVue Spectral Domain Optical Coherence Tomography (SDâOCT). Tests were conducted in a random order with results masked to the clinician conducting the reference ophthalmic examination. The accuracy of each test was determined by analysis of the area under the receiver operator characteristic curve (AUROC).
Results
A4FTp flicker thresholds were stable, with standard deviations of only 0.52 decilog (dL) for T8, increasing to 1.32 dL for T12, and no significant flicker sensitivity threshold improvement over the 10 repeat runs. T8 was superior to T12 on several other measures, so it was used for the remaining comparisons. In terms of diagnostic accuracy, the mean AUROC for the three tests were A4FTp [T8 criterion; 0.82, 95% confidence interval (0.73â0.92)]; SDâOCT [any RNFL parameter p < 1% level; 0.90 (0.83â0.97)]; and FDT [one or more locations missed at p < 5% level; 0.91 (0.82â0.96)]. There was no statistical difference in AUROC between A4FTp and SDâOCT (p = 0.18) or FDT (p = 0.12). The A4FTp test duration averaged just over 2 min per eye, taking approximately oneâthird of the time for completion of the HFA SITA 24â2 algorithm (conducted as part of the reference examination) and twice the time for the suprathreshold FDT.
Conclusion
Test accuracy for the A4FTp was comparable to those of the FDT and SDâOCT for the detection of COAG. Time taken to complete the A4FTp was relatively short and initial results are promising. With further refinement, the A4FTp could have a future role in glaucoma detection
Effects of question formats on causal judgments and model evaluation
Evaluation of causal reasoning models depends on how well the subjects' causal beliefs are assessed. Elicitation of causal beliefs is determined by the experimental questions put to subjects. We examined the impact of question formats commonly used in causal reasoning research on participant's responses. The results of our experiment (Study 1) demonstrate that both the mean and homogeneity of the responses can be substantially influenced by the type of question (structure induction versus strength estimation versus prediction). Study 2A demonstrates that subjects' responses to a question requiring them to predict the effect of a candidate cause can be significantly lower and more heterogeneous than their responses to a question asking them to diagnose a cause when given an effect. Study 2B suggests that diagnostic reasoning can strongly benefit from cues relating to temporal precedence of the cause in the question. Finally, we evaluated 16 variations of recent computational models and found the model fitting was substantially influenced by the type of questions. Our results show that future research in causal reasoning should place a high priority on disentangling the effects of question formats from the effects of experimental manipulations, because that will enable comparisons between models of causal reasoning uncontaminated by method artifact
Comparison of Nasopharyngeal Samples for SARSâCoV â2 Detection in a Paediatric Cohort
Aim: The diagnosis of coronavirus disease 2019 (COVID-19) depends on accurate and rapid testing. Choosing an appropriate sample may impact diagnosis. Naso-oropharyngeal swabs (NOS) are most frequently used, despite several limitations. Since studies suggest nasopharyngeal aspirate (NPA) as a superior alternative in children, we hypothesised collecting both nasopharyngeal swab and aspirate would improve our diagnostic accuracy.
Methods: Observational, longitudinal, prospective study from 7 March to 7 May in a tertiary paediatric hospital in Lisbon. The objective was to compare the rate of detection of SARS-CoV-2 between NOS and NPA samples collected simultaneously.
Results: A total of 438 samples collected from 85 patients with confirmed COVID-19. There were 47.7% overall positive specimens - 32% (70/219) positive NOS and 63.5% (139/219) positive NPA. The tests were 67.6% concordant (k = 0.45). 50.3% had positive NPA with negative NOS, while 1.3% had positive NOS with negative NPA. NPA proved to be more sensitive (98.6% with 95% confidence interval 91.2-99.9% vs. 49.6% with 95% confidence interval 41.1-58.2%, P < 0.001). Additionally, the difference between NPA and NOS positive samples was statistically significant across all population groups (age, health condition, clinical presentation, contact with COVID-19 patients or need for hospitalisation), meaning NPA is more sensitive overall.
Conclusions: Nasopharyngeal aspirates had greater sensitivity than naso-oropharyngeal swabs in detecting SARS-CoV-2. Our results suggest paediatric patients would benefit from collecting nasopharyngeal aspirates in hospital settings, whenever feasible, to improve diagnosis of COVID-19.info:eu-repo/semantics/publishedVersio
Diagnostic accuracy of myocardial perfusion imaging with czt technology. Systemic review and meta-analysis of comparison with invasive coronary angiography
OBJECTIVES:
This study sought to summarize the evidence on stress myocardial perfusion imaging (MPI) using cadmium-zinc-telluride (CZT) technology for the diagnosis of obstructive coronary artery disease (CAD). The CZT cameras are newly introduced, and comparative data with the conventional Anger technology (Anger-MPI) are lacking.
BACKGROUND:
The diagnostic accuracy of Anger-MPI for detection of angiographically significant CAD is well established; however, less evidence is available on the diagnostic accuracy of CZT-MPI.
METHODS:
Clinical studies comparing CZT-MPI and invasive coronary angiography were systematically searched and abstracted. Calculations of diagnostic accuracy, including sensitivity, specificity, likelihood ratios, and diagnostic odds ratio, were obtained with fixed and random effects, reporting point estimates and 95% confidence intervals.
RESULTS:
Based on our search, a total of 16 studies (N = 2,092) were included. The sensitivity of CZT-MPI was 0.84 (95% confidence interval [CI]: 0.78 to 0.89), whereas the specificity of 0.69 (95% CI: 0.62 to 0.76) was significantly reduced. The positive likelihood ratio was 2.73 (95% CI: 2.21 to 3.39), the negative likelihood ratio was 0.24 (95% CI: 0.17 to 0.31), and the diagnostic odds ratio was 11.93 (95% CI: 7.84 to 17.42). At subgroup and meta-regression analyses, the diagnostic accuracy between D-SPECT and Discovery cameras was similar (p = 0.711) and not impacted upon by smaller sample size studies (p = 0.573).
CONCLUSIONS:
CZT-MPI has satisfactory sensitivity for angiographically significant CAD, but its suboptimal specificity warrants further development and research
ASPIRE-2-PREVENT: a survey of lifestyle, risk factor management and cardioprotective medication in patients with coronary heart disease and people at high risk of developing cardiovascular disease in the UK.
OBJECTIVE: To determine in patients with coronary heart disease (CHD) and people at high risk of developing cardiovascular disease (CVD) whether the Joint British Societies' guidelines on CVD prevention (JBS2) are followed in everyday clinical practice. DESIGN: A cross-sectional survey was undertaken of medical records and patient interviews and examinations at least 6 months after the recruiting event or diagnosis using standardised instruments and a central laboratory for measurement of lipids and glucose. SETTINGS: The ASPIRE-2-PREVENT survey was undertaken in 19 randomly selected hospitals and 19 randomly selected general practices in 12 geographical regions in England, Northern Ireland, Wales and Scotland. PATIENTS: In hospitals, 1474 consecutive patients with CHD were identified and 676 (25.6% women) were interviewed. In general practice, 943 people at high CVD risk were identified and 446 (46.5% women) were interviewed. RESULTS: The prevalence of risk factors in patients with CHD and high-risk individuals was, respectively: smoking 14.1%, 13.3%; obesity 38%, 50.2%; not reaching physical activity target 83.3%, 85.4%; blood pressure â„130/80 mm Hg (patients with CHD and self-reported diabetes) or â„140/85 mm Hg (high-risk individuals) 46.9%, 51.3%; total cholesterol â„4 mmol/l 52.6%, 78.7%; and diabetes 17.8%, 43.8%. CONCLUSIONS: The potential among patients with CHD and individuals at high risk of developing CVD in the UK to achieve the JBS2 lifestyle and risk factor targets is considerable. CVD prevention needs a comprehensive multidisciplinary approach, addressing all aspects of lifestyle and risk factor management. The challenge is to engage and motivate cardiologists, physicians and other health professionals to routinely practice high quality preventive cardiology in a healthcare system which must invest in prevention
Cultural imagery and statistical models of the force of mortality: Addison, Gompertz and Pearson
We describe selected artistic and statistical depictions of the force of mortality (hazard or mortality rate), which is a concept that has long preoccupied actuaries, demographers and statisticians. We provide a more graphic form for the force-of-mortality function that makes the relationship between its constituents more explicit. The 'Bridge of human life' in Addison's allegorical essay of 1711 provides a particularly vivid image, with the forces depicted as external. The model that was used by Gompertz in 1825 appears to treat the forces as internal. In his 1897 essay Pearson mathematically modernized 'the medieval conception of the relation between Death and Chance' by decomposing the full mortality curve into five distributions along the age axis, the results of five 'marksmen' aiming at the human mass crossing this bridge. We describe Addison's imagery, comment briefly on Gompertz's law and the origin of the term 'force of mortality', describe the background for Pearson's essay, as well as his imagery and statistical model, and give the bridge of life a modern form, illustrating it via statistical animation
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