Evaluations of forensic observations considering activity level propositions are becoming more common place in forensic institutions. A measure that can be taken to interrogate the evaluation for robustness is called sensitivity analysis. A sensitivity analysis explores the sensitivity of the evaluation to the data used when assigning probabilities, or to the level of uncertainty surrounding a probability assignment, or to the choice of various assumptions within the model. There have been a number of publications that describe sensitivity analysis in technical terms, and demonstrate their use, but limited literature on how that theory can be applied in practice. In this work we provide some simplified examples of how sensitivity analyses can be carried out, when they are likely to show that the evaluation is sensitive to underlying data, knowledge or assumptions, how to interpret the results of sensitivity analysis, and how the outcome can be reported. We also provide access to an application to conduct sensitivity analysis.
DOCUMENT
Standard SARS-CoV-2 testing protocols using nasopharyngeal/throat (NP/T) swabs are invasive and require trained medical staff for reliable sampling. In addition, it has been shown that PCR is more sensitive as compared to antigen-based tests. Here we describe the analytical and clinical evaluation of our in-house RNA extraction-free saliva-based molecular assay for the detection of SARS-CoV-2. Analytical sensitivity of the test was equal to the sensitivity obtained in other Dutch diagnostic laboratories that process NP/T swabs. In this study, 955 individuals participated and provided NP/T swabs for routine molecular analysis (with RNA extraction) and saliva for comparison. Our RT-qPCR resulted in a sensitivity of 82,86% and a specificity of 98,94% compared to the gold standard. A false-negative ratio of 1,9% was found. The SARS-CoV-2 detection workflow described here enables easy, economical, and reliable saliva processing, useful for repeated testing of individuals.
LINK
PURPOSE: To analyse how decisions to dichotomise the frequency and impediment of phantom pain into absent and present influence the outcome of studies by performing a sensitivity analysis on an existing database.METHOD: Five hundred and thirty-six subjects were recruited from the database of an orthopaedic workshop and filled out a questionnaire in which the following items were assessed: demographics, side, date, level and reason of amputation, presence and frequency of phantom sensations, phantom pain and stump pain, and impediment due to phantom pain.RESULTS: The prevalence of phantom pain ranged from 7-72% when different cut off points for the frequency of phantom pain were applied. The significance of the various risk factors for the prevalence of phantom pain changed when different cut off points were applied. Only stump pain and phantom sensations were significant risk factors for all cut off points. Risk factors for the impediment of phantom pain changed when different cut off points were applied and these risk factors were different from those for the prevalence of phantom pain.CONCLUSION: The choice of cut off points influences the outcome of phantom pain studies considerably. This study provides some insight into the differences in prevalence and risk factors found in literature.
DOCUMENT
Local governments in Western Europe increasingly use city time-access regulations to improve social sustainability. These regulations significantly influence the distribution process of retail chain organizations. This paper studies the impact of governmental time-window pressure on retailers' logistical concepts and the consequential financial and environmental distribution performance. We determine which dimensions in the retailer's logistical concept determine its cost and emission sensitivity to increasing time-window pressure. Our research is based on a multiple case study of fourteen Dutch retail cases in different sectors and with different store formulas. The retailers provided all organizational, flow and cost data of their secondary distribution (between distribution center and stores). We use these data to calculate the impacts of different time-window pressure scenarios, including the current situation, using vehicle routing software. It appears that cost and emissions increases are moderate, when few cities are affected. However, as more cities are affected, costs and emissions increase considerably, particularly if time-window lengths become shorter. Time-windows harmonized between cities lead to fewer negative effects. We find various dimensions that contribute to reducing a retailer's sensitivity to time-window pressure. We formulate conclusions hypothesizing the links between time-window pressure, its effects, and the dimensions that determine these effects. © 2007 Elsevier B.V. All rights reserved.
LINK
Insider ethnographic analysis is used to analyze change processes in an engineering department. Distributed leadership theory is used as conceptual framework.
DOCUMENT
In this study we measured the performance times on the Wheelchair Mobility Performance (WMP) test during different test conditions to see if the performance times changed when wheelchair settings were changed. The overall performance time on the WMP test increased when the tire pressure was reduced and also when extra mass was attached to the wheelchair. It can be concluded that the WMP test is sensitive to changes in wheelchair settings. It is recommended to use this field-based test in further research to investigate the effect of wheelchair settings on mobility performance time. Objective: The Wheelchair Mobility Performance (WMP) test is a reliable and valid measure to assess mobility performance in wheelchair basketball. The aim of this study was to examine the sensitivity to change of the WMP test by manipulating wheelchair configurations. Methods: Sixteen wheelchair basketball players performed the WMP test 3 times in their own wheelchair: (i) without adjustments (“control condition”); (ii) with 10 kg additional mass (“weighted condition”); and (iii) with 50% reduced tyre pressure (“tyre condition”). The outcome measure was time (s). If paired t-tests were significant (p < 0.05) and differences between conditions were larger than the standard error of measurement, the effect sizes (ES) were used to evaluate the sensitivity to change. ES values ≥0.2 were regarded as sensitive to change. Results: The overall performance times for the manipulations were significantly higher than the control condition, with mean differences of 4.40 s (weight – control, ES = 0.44) and 2.81 s (tyre – control, ES = 0.27). The overall performance time on the WMP test was judged as sensitive to change. For 8 of the 15 separate tasks on the WMP test, the tasks were judged as sensitive to change for at least one of the manipulations. Conclusion: The WMP test can detect change in mobility performance when wheelchair configurations are manipulated. https://www.medicaljournals.se/jrm/content/html/10.2340/16501977-2341
MULTIFILE
Mycotoxins are small (MW approximately 700), toxic chemical products formed as secondary metabolites by a few fungal species that readily colonise crops and contaminate them with toxins in the field or after harvest. Ochratoxins and Aflatoxins are mycotoxins of major significance and hence there has been significant research on broad range of analytical and detection techniques that could be useful and practical. Due to the variety of structures of these toxins, it is impossible to use one standard technique for analysis and/or detection. Practical requirements for high-sensitivity analysis and the need for a specialist laboratory setting create challenges for routine analysis. Several existing analytical techniques, which offer flexible and broad-based methods of analysis and in some cases detection, have been discussed in this manuscript. There are a number of methods used, of which many are lab-based, but to our knowledge there seems to be no single technique that stands out above the rest, although analytical liquid chromatography, commonly linked with mass spectroscopy is likely to be popular. This review manuscript discusses (a) sample pre-treatment methods such as liquid-liquid extraction (LLE), supercritical fluid extraction (SFE), solid phase extraction (SPE), (b) separation methods such as (TLC), high performance liquid chromatography (HPLC), gas chromatography (GC), and capillary electrophoresis (CE) and (c) others such as ELISA. Further currents trends, advantages and disadvantages and future prospects of these methods have been discussed.
DOCUMENT
STUDY DESIGN: Meta-analysis.OBJECTIVES: To define the accuracy of clinical tests for assessing anterior cruciate ligament (ACL) ruptures.BACKGROUND: The cruciate ligaments, and especially the ACL, are among the most commonly injured structures of the knee. Given the increasing injury prevalence, there is undoubtedly a growing need for clinical decision making of health care providers. We reviewed the literature to analyze the diagnostic accuracy of the clinical examination for assessing ACL ruptures.METHODS AND MEASURES: MEDLINE (1966 to April 2005), EMBASE (1989 to April 2005), and CINAHL (1982 to April 2005) searches were performed. Also reference lists of the included studies were reviewed. Studies selected for data extraction were those that addressed the accuracy of at least 1 physical diagnostic test for ACL rupture and compared the performance of the clinical examination of the knee with a reference standard, such as arthroscopy, arthrotomy, or MRI. Searching was limited to English, German, and Dutch languages.RESULTS: Twenty-eight studies that assessed the accuracy of clinical tests for diagnosing ACL ruptures met the inclusion criteria. Study results were, however, heterogeneous. The Lachman test is the most valid test to determine ACL tears, showing a pooled sensitivity of 85% (95% confidence interval [CI], 83-87) and a pooled specificity of 94% (95% CI, 92-95). The pivot shift test is very specific, namely 98% (95% CI, 96-99), but has a poor sensitivity of 24% (95% CI, 21-27). The anterior drawer test shows good sensitivity and specificity in chronic conditions, respectively 92% (95% CI, 88-95) and 91% (95% CI, 87-94), but not in acute conditions.CONCLUSION: In case of suspected ACL injury it is recommended to perform the Lachman test. Because the pivot shift test is very specific both in acute as well as in chronic conditions, it is recommended to perform the pivot shift test as well.
DOCUMENT
The aim of this study was to assess the predictive ability of the frailty phenotype (FP), Groningen Frailty Indicator (GFI), Tilburg Frailty Indicator (TFI) and frailty index (FI) for the outcomes mortality, hospitalization and increase in dependency in (instrumental) activities of daily living ((I)ADL) among older persons. This prospective cohort study with 2-year follow-up included 2420 Dutch community-dwelling older people (65+, mean age 76.3±6.6 years, 39.5% male) who were pre-frail or frail according to the FP. Mortality data were obtained from Statistics Netherlands. All other data were self-reported. Area under the receiver operating characteristic curves (AUC) was calculated for each frailty instrument and outcome measure. The prevalence of frailty, sensitivity and specifcity were calculated using cutoff values proposed by the developers and cutoff values one above and one below the proposed ones (0.05 for FI). All frailty instruments poorly predicted mortality, hospitalization and (I)ADL dependency (AUCs between 0.62–0.65, 0.59–0.63 and 0.60–0.64, respectively). Prevalence estimates of frailty in this population varied between 22.2% (FP) and 64.8% (TFI). The FP and FI showed higher levels of specifcity, whereas sensitivity was higher for the GFI and TFI. Using a different cutoff point considerably changed the prevalence, sensitivity and specifcity. In conclusion, the predictive ability of the FP, GFI, TFI and FI was poor for all outcomes in a population of pre-frail and frail community-dwelling older people. The FP and the FI showed higher values of specifcity, whereas sensitivity was higher for the GFI and TFI.
DOCUMENT
Rationale: Diagnosis of sarcopenia in older adults is essential for early treatment in clinical practice. Bio-electrical impedanceanalysis (BIA) may be a valid means to assess appendicular lean mass (ALM) in older adults, but limited evidence is available.Therefore, we aim to evaluate the validity of BIA to assess ALM in older adults.Methods: In 215 community dwelling older adults (age ≥ 55 years), ALM was measured by BIA (Tanita MC-780; 8-points) andcompared with dual-energy X-ray absorptiometry (DXA, Hologic Discovery A) as reference. Validity for assessing absolute values ofALM was evaluated by: 1) bias (mean difference), 2) percentage of accurate predictions (within 5% of DXA values), 3) individualerror (root mean squared error (RMSE), mean absolute deviation), 4) limits of agreement (Bland-Altman analysis). For diagnosis oflow ALM, the lowest quintile of ALM by DXA was used (below 21.4 kg for males and 15.4 for females). Sensitivity and specificityof detecting low ALM by BIA were assessed.Results: Mean age of the subjects was 71.9 ± 6.4, with a BMI of 25.8 ± 4.2 kg/m2, and 70% were females. BIA slightlyunderestimated ALM compared to DXA with a mean bias of -0.6 ± 0.2 kg. The percentage accurate predictions was 54% withRMSE 1.6 kg and limits of agreements -3.0 – +1.8 kg. Sensitivity was 79%, indicating that 79% of subjects with low ALMaccording to DXA also had low ALM with the BIA. Specificity was 90%, indicating that 90% of subjects with ‘no low’ ALMaccording to DXA also had ‘no low’ ALM with the BIA.Conclusions: This comparison showed a poor validity of BIA to assess absolute values of ALM, but a reasonable sensitivity andspecificity to diagnose a low level of ALM in community-dwelling older adults in clinical practice.
DOCUMENT
