Strategies for screening young stock for antibodies - optimising numbers to test, cut-points, & predictive values for bovine viral diarrhoea virus.
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ABSTRACT:
SUBMITTER: Humphry RW
PROVIDER: S-EPMC6014978 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BackgroundBovine viral diarrhoea virus (BVDV) causes substantial economic losses to the cattle industry; however, control and eradication can be achieved by identifying and removing persistently infected cattle from the herd. Each UK nation has separate control programmes. The English scheme, BVDFree, started in 2016 and is voluntary.MethodsWe analysed the test results submitted to BVDFree from 5847 herds between 2016 and 2020.ResultsIn 2020, 13.5% of beef breeders and 20.0% of dairy herds that submitted tests had at least one positive (virus/antibody) test result. Although lower than in previous years, there was no clear trend in the proportion of positive tests over time. In virus testing herds, 0.4% of individual tests were positive in 2020, and 1.5% of individual tests were positive in BVDV-positive virus testing herds. Dairy herds and larger herds were more likely to join BVDFree, and dairy herds were also more likely to virus test than beef breeder herds. Larger herds, herds that used virus testing and herds that had BVDV-positive test results were more likely to continue submitting tests to BVDFree.ConclusionsThe findings provide a benchmark for the status of BVDV control in England; continued analysis of test results will be important to assess progress towards eradication.
| S-EPMC9546236 | biostudies-literature
Project description:PurposeWe assessed the impact of applying different SARC-F cut-points for the identification of muscle weakness in an older clinical population.MethodsWe included 159 men and 311 women aged 56-98 years who had completed the SARC-F questionnaire and had their maximum grip strength measured at an Older People's Medicine Day Unit. We applied cut-points of ≥ 4, 3 and 2 to SARC-F and tested agreement with muscle weakness (grip strength < 27kg men, < 16kg women) in analyses stratified by sex and obesity status.ResultsPrevalence of muscle weakness was 86.8% and 82.6% in men and women, respectively. Sensitivity of the SARC-F increased at lower cut-points (e.g. 81% for ≥ 4 vs 97% for ≥ 2 in women). There was typically greater sensitivity among women than men and among those classified as obese vs non-obese.ConclusionsThese findings suggest that different cut-points may be required to optimise the utility of SARC-F for identifying muscle weakness in different patient sub-groups.
| S-EPMC10754758 | biostudies-literature
Project description:BackgroundSince symptomatology is a major predictor of quality of life and an endpoint for the management of atrial fibrillation (AF), practical approaches for objectively interpreting symptom burden and functional impairment are needed.AimsWe aimed to provide cut-off values for two frequently used field tests to be able to objectively interpret symptom burden in atrial fibrillation.MethodsOne hundred twenty-five patients with AF were evaluated with European Heart Rhythm Association (EHRA) score, 6-min walk test (6MWT), 30 s sit-to-stand test (30 s-STST), Short-Form 36 (SF-36), International Physical Activity Questionnaire-Short Form (IPAQ-SF), and spirometry. Patients with EHRA 1 were classified as "asymptomatic", and those with EHRA 2-4 as "symptomatic". Cut-off values of 6MWT and 30 s-STST for discriminating between these patients were calculated.ResultsThe optimal cut-off value was "450 m" for 6MWT (sensitivity: 0.71; specificity of 0.79) and "11 repetitions" for 30 s-STST (sensitivity 0.77; specificity of 0.70). Area under ROC curve was 0.75 for both tests (p < 0.001). Discriminative properties of the two tests were similar, and they were significantly correlated (r = 0.58; p < 0.001). Subgroup analysis revealed patients below cut-off values also had worse outcomes in SF-36, IPAQ-SF, and spirometry.ConclusionsIn patients with AF, walking < 450 m in 6MWT or performing < 11 repetitions in 30 s-STST indicates increased symptom burden, as well as impaired exercise capacity, quality of life, physical activity participation, and pulmonary function. These cut-off values may help identifying patients who may require adjustments in their routine treatment or who may benefit from additional rehabilitative approaches.
| S-EPMC8783771 | biostudies-literature
Project description:Background: The assessment of severity is crucial in the management of community-acquired pneumonia (CAP). It remains unknown whether updating cut-off values of severity scoring systems orchestrate improvement in predictive accuracy.Methods: 3,212 patients with CAP were recruited to two observational prospective cohort studies. Three bettered scoring systems were derived from the corresponding well-established and extensively used pneumonia-specific severity scoring systems, i.e. pneumonia severity index, minor criteria and CURB-65 (confusion, urea >7 mmol/L, respiratory rate ≥30/min, low blood pressure, and age ≥65 years) score, with the updating cut-off values for tachypnea and low blood pressure. Cronbach α was employed to determine construct validity. Discrimination was valued by calculating the area under the receiver operating characteristic curve (AUROC) and net reclassification improvement (NRI).Results: Respiratory rate ≥22/min and systolic blood pressure ≤100 mm Hg were performed better than respiratory rate ≥30/min and hypotension for predicting mortality in the derivation cohort, respectively (AUROC, 0.823 vs 0.519, 0.688 vs 0.622; NRI, 0.61, 0.13). Bettered scoring systems orchestrated higher convergences, indicated by greater Cronbach α and more decrease in Cronbach α if the updating cut-off values were deleted. The six scoring systems agreed well with one another. Bettered- pneumonia severity index, minor criteria and CURB-65 score showed higher associations with severity and mortality rates and demonstrated greater predictive accuracies for mortality compared with the corresponding original systems (AUROC, 0.939 vs 0.883, 0.909 vs 0.871, 0.913 vs 0.859; NRI, 0.113, 0.076, 0.108; respectively). The validation cohort confirmed a similar pattern.Conclusions: Updating cut-off values of severity scoring systems for CAP orchestrate improvement in predictive accuracy, suggesting that it may facilitate the rationalization of clinical triage decision-making and further reduce mortality. The current studies provide the first known prospective evidence of potential benefit of the updating cut-off values of severity scoring systems for CAP in predictive accuracy.Key messagesUpdating cut-off values were performed better for predicting mortality.Bettered scoring systems orchestrated higher convergences.Bettered scoring systems demonstrated greater predictive accuracies for mortality.
| S-EPMC10120525 | biostudies-literature
Project description:Background & aimsNoninvasive tests used in colorectal cancer screening, such as the fecal immunochemical test (FIT), are more acceptable but detect neoplasias with lower levels of sensitivity than colonoscopy. We investigated whether lowering the cut-off concentration of hemoglobin for designation as an abnormal FIT result increased the detection of advanced neoplasia in a mailed outreach program.MethodsWe performed a prospective study of 17,017 uninsured patients, age 50 to 64 years, who were not current with screening and enrolled in a safety-net system in Texas. We reduced the cut-off value for an abnormal FIT result from 20 or more to 10 or more ?g hemoglobin/g feces a priori. All patients with abnormal FIT results were offered no-cost diagnostic colonoscopy. We compared proportions of patients with abnormal FIT results and neoplasia yield for standard vs lower cut-off values, as well as absolute hemoglobin concentration distribution among 5838 persons who completed the FIT. Our primary aim was to determine the effects of implementing a lower hemoglobin concentration cut-off value on colonoscopy demand and yield, specifically colorectal cancer (CRC) and advanced neoplasia detection, compared with the standard, higher, hemoglobin concentration cut-off value.ResultsThe proportions of patients with abnormal FIT results were 12.3% at the 10 or more ?g hemoglobin/g feces and 6.6% at the standard 20 or more ?g hemoglobin/g feces cut-off value (P = .0013). Detection rates for the lower vs the standard threshold were 10.2% vs 12.7% for advanced neoplasia (P = .12) and 0.9% vs 1.2% for CRC (P = .718). The positive predictive values were 18.9% for the lower threshold vs 24.4% for the standard threshold for advanced neoplasia (P = .053), and 1.7% vs 2.4% for CRC (P = .659). The number needed to screen to detect 1 case with advanced neoplasia was 45 at the lower threshold compared with 58 at the standard threshold; the number needed to scope to detect 1 case with advanced neoplasia increased from 4 to 5. Most patients with CRC (72.7%) or advanced adenoma (67.3%) had hemoglobin concentrations of 20 or more ?g/g feces. In the group with 10 to 19 ?g hemoglobin/g feces, there were 3 patients with CRC (3 of 11; 27.3%) and 36 with advanced adenoma (36 of 110; 32.7%) who would not have been detected at the standard positive threshold (advanced neoplasia Pcomparison < .001). The proportion of patients found to have no neoplasia after an abnormal FIT result (false positives) was not significantly higher with the lower cut-off value (44.4%) than the standard cut-off value (39.1%) (P = .1103).ConclusionsIn a prospective study of 17,017 uninsured patients, we found that reducing the abnormal FIT result cut-off value (to ?10 ?g hemoglobin/g feces) might increase detection of advanced neoplasia, but doubled the proportion of patients requiring a diagnostic colonoscopy. If colonoscopy capacity permits, health systems that use quantitative FITs should consider lowering the abnormal cut-off value to optimize CRC detection and prevention. (ClinicalTrials.gov no: NCT01946282.).
| S-EPMC7731666 | biostudies-literature
Project description:Background:Criterion-referenced cut-points for field-based aerobic fitness for children and adolescents are lacking. This study aimed to determine the associations between aerobic fitness and obesity to propose criterion-referenced cut-points for boys and girls (6-17 years). Methods:A total of 61,465 children and adolescents aged 11.2 ± 2.0 years were recruited from 27 sites (all 26 states and Federal District) across Brazil. Aerobic fitness was assessed using 9-min walk/run test reported as distance attained during the test. Body mass index was calculated from measured height and weight and was used to identify obesity. Results:The distance covered in the 9-min walk/run test (area under curve > 0.65) had satisfactory predictive ability for obesity. Sensitivity and specificity were moderate (>60%) to strong (>70%) for all age- and sex-specific cut-points. For boys, the optimal physical performance cut-points were, approximately, 1,200 m from 6 to 8 years, 1,300 m from 9 to 11 years, 1,380 m from 12 to 14 years, 1,520 m from 15 to 17 years. For girls, the best cut-points were, approximately, 1,070 m from 6 to 8 years, 1,160 m from 9 to 11 years and 1,200 m from 12 to 17 years. Conclusions:The 9-min walk/run test had satisfactory predictive ability for obesity in children and adolescents. The physical fitness cut-points proposed in the present study varied according to age and sex and could be useful and practical tools to identify low levels of physical fitness in children and adolescents in Brazil.
| S-EPMC7034371 | biostudies-literature
Project description:PurposePhysical activity (PA) intensity is expressed as either absolute or relative intensity. Absolute intensity refers to the energy required to perform an activity. Relative intensity refers to a level of effort that takes into account how hard an individual is working relative to their maximum capacity. We sought to develop methods for obtaining individualized relative-intensity accelerometer cut points using data from a maximal graded exercise treadmill test (GXT) so that each individual has their own cut point.MethodsA total of 2363 men and women 38 to 50 yr old from the CARDIA fitness study wore ActiGraph 7164 accelerometers during a maximal GXT and for seven consecutive days in 2005-2006. Using mixed-effects regression models, we regressed accelerometer counts on heart rate as a percentage of maximum (%HRmax) and on RPE. Based on these two models, we obtained a moderate-intensity (%HRmax = 64% or RPE = 12) count cut point that is specific to each participant. We applied these subject-specific cut points to the available CARDIA accelerometer data.ResultsUsing RPE, the mean moderate-intensity accelerometer cut point was 4004 (SD = 1120) counts per minute. On average, cut points were higher for men (4189 counts per minute) versus women (3865 counts per minute) and were higher for Whites (4088 counts per minute) versus African Americans (3896 counts per minute). Cut points were correlated with body mass index (rho = -0.11) and GXT duration (rho = 0.33). Mean daily minutes of absolute- and relative-intensity moderate to vigorous PA were 34.1 (SD = 31.1) min·d and 9.1 (SD = 18.2) min·d, respectively. RPE cut points were higher than those based on %HRmax. This is likely due to some participants ending the GXT before achieving their HRmax.ConclusionsAccelerometer-based relative-intensity PA may be a useful measure of intensity relative to maximal capacity.
| S-EPMC6962549 | biostudies-literature
Project description:To identify emerging interdependencies between traded stocks we investigate the behavior of the stocks of FTSE 100 companies in the period 2000-2015, by looking at daily stock values. Exploiting the power of information theoretical measures to extract direct influences between multiple time series, we compute the information flow across stock values to identify several different regimes. While small information flows is detected in most of the period, a dramatically different situation occurs in the proximity of global financial crises, where stock values exhibit strong and substantial interdependence for a prolonged period. This behavior is consistent with what one would generally expect from a complex system near criticality in physical systems, showing the long lasting effects of crashes on stock markets.
| S-EPMC5444585 | biostudies-literature
Project description:To determine a high fear cut-off point score for the Dental Fear Survey (DFS) using a single-item self-report questionnaire.The DFS, a 20-item questionnaire assessing fear of dental treatment, was completed by 1,256 participants with a mean age of 22.3 years (SD = 5.1). Another self-report questionnaire was used to collect data on previous dental experiences. A high fear cut-off point score was determined by calculating the receiver operating characteristic (ROC) curve for the DFS. Descriptive statistics and multinomial logistic regression were calculated; a significance level of p < 0.05 was used for all tests.The ROC curve indicated that a DFS score ? 53 corresponds to a sensitivity of 88.9% and a specificity of 92.5%. Most participants (n = 895; 71.5%) reported no fear of going to the dentist. There was significant association between DFS score and fear assessed with the question "Are you fearful of going to the dentist?" (p < 0.001).A cut-off point of 53 on the DFS total score represents the best compromise between sensitivity and specificity and can be used to predict high dental fear.
| S-EPMC4602336 | biostudies-literature
Project description:BACKGROUND:Body mass index (BMI) and waist circumference (WC) are used to define cardiovascular and type 2 diabetes risk. We aimed to derive appropriate BMI and WC obesity cut-off points in a migrant South Asian population. METHODS:4688 White Europeans and 1333 South Asians resident in the UK aged 40-75 years inclusive were screened for type 2 diabetes. Principal components analysis was used to derive a glycaemia, lipid, and a blood pressure factor. Regression models for each factor, adjusted for age and stratified by sex, were used to identify BMI and WC cut-off points in South Asians that correspond to those defined for White Europeans. FINDINGS:For South Asian males, derived BMI obesity cut-off points equivalent to 30.0 kg/m(2) in White Europeans were 22.6 kg/m(2) (95% Confidence Interval (95% CI) 20.7 kg/m(2) to 24.5 kg/m(2)) for the glycaemia factor, 26.0 kg/m(2) (95% CI 24.7 kg/m(2) to 27.3 kg/m(2)) for the lipid factor, and 28.4 kg/m(2) (95% CI 26.5 kg/m(2) to 30.4 kg/m(2)) for the blood pressure factor. For WC, derived cut-off points for South Asian males equivalent to 102 cm in White Europeans were 83.8 cm (95% CI 79.3 cm to 88.2 cm) for the glycaemia factor, 91.4 cm (95% CI 86.9 cm to 95.8 cm) for the lipid factor, and 99.3 cm (95% CI 93.3 cm to 105.2 cm) for the blood pressure factor. Lower ethnicity cut-off points were seen for females for both BMI and WC. CONCLUSIONS:Substantially lower obesity cut-off points are needed in South Asians to detect an equivalent level of dysglycemia and dyslipidemia as observed in White Europeans. South Asian ethnicity could be considered as a similar level of risk as obesity (in White Europeans) for the development of type 2 diabetes.
| S-EPMC3198431 | biostudies-literature