Evaluating observer bias and seasonal detection rates in amphibian pathogen eDNA collections by citizen scientists

2019 ◽  
Vol 134 (1) ◽  
pp. 15-24 ◽  
Author(s):  
JT Julian ◽  
GW Glenney ◽  
C Rees
Keyword(s):  
Observer Bias ◽  
Detection Rates ◽  
Amphibian Pathogen

Observer bias in perceptions of responsibility.

1993 ◽  
Vol 48 (5) ◽  
pp. 584-584
Author(s):  
Allan J. Davison ◽  
Nancy C. Higgins
Keyword(s):  
Observer Bias

Predicting Fetal Chromosome Anomalies in the First Trimester Using Pregnancy Associated Plasma Protein-A: A Comparison of Statistical Methods

1993 ◽  
Vol 32 (02) ◽  
pp. 175-179 ◽  
Author(s):  
B. Brambati ◽  
T. Chard ◽  
J. G. Grudzinskas ◽  
M. C. M. Macintosh
Keyword(s):  
Logistic Regression ◽  
General Population ◽  
Likelihood Ratio ◽  
False Positive ◽  
False Positive Rate ◽  
Ratio Method ◽  
Detection Rates ◽  
Gaussian Distributions ◽  
Positive Rate ◽  
Likelihood Ratio Method

Abstract:The analysis of the clinical efficiency of a biochemical parameter in the prediction of chromosome anomalies is described, using a database of 475 cases including 30 abnormalities. A comparison was made of two different approaches to the statistical analysis: the use of Gaussian frequency distributions and likelihood ratios, and logistic regression. Both methods computed that for a 5% false-positive rate approximately 60% of anomalies are detected on the basis of maternal age and serum PAPP-A. The logistic regression analysis is appropriate where the outcome variable (chromosome anomaly) is binary and the detection rates refer to the original data only. The likelihood ratio method is used to predict the outcome in the general population. The latter method depends on the data or some transformation of the data fitting a known frequency distribution (Gaussian in this case). The precision of the predicted detection rates is limited by the small sample of abnormals (30 cases). Varying the means and standard deviations (to the limits of their 95% confidence intervals) of the fitted log Gaussian distributions resulted in a detection rate varying between 42% and 79% for a 5% false-positive rate. Thus, although the likelihood ratio method is potentially the better method in determining the usefulness of a test in the general population, larger numbers of abnormal cases are required to stabilise the means and standard deviations of the fitted log Gaussian distributions.

Opportunistic Colorectal Cancer Screening using Colonoscopy. Comparative Results between two Historical Cohorts in Bucharest, Romania

2015 ◽  
Vol 24 (2) ◽  
pp. 171-176 ◽  
Author(s):  
Elena Mirela Ionescu ◽  
Tudor Nicolaie ◽  
Serban Ion Gologan ◽  
Ana Mocanu ◽  
Cristina Ditescu ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Screening Program ◽  
Advanced Adenoma ◽  
Detection Rates ◽  
Incidence And Mortality ◽  
Organized Screening Program ◽  
History Of ◽  
Comparative Results ◽  
Asymptomatic Individuals ◽  
Second Period

Background & Aims: Even though Romania has one of the highest incidence and mortality in colorectal cancer (CRC) in Europe, there is currently no organized screening program. We aimed to assess the results of our opportunistic CRC screening using colonoscopy.Methods: A single center retrospective study to include all opportunistic screening colonoscopies performed in two 18 month periods (2007-2008 and 2012-2013) was designed. All asymptomatic individuals without a personal or family history of adenoma or CRC and with complete colonoscopy performed in these two time periods were included.Results: We included 1,807 individuals, 882 in the first period, 925 in the second period. There were 389 individuals aged below 50, 1,351 between 50 and 75 and 67 older than 75 years. There were 956 women (52.9%), with a mean age of 58.5 (median 59, range 23-97). The detection rates were 12.6% for adenomas (6.1% for advanced adenoma) and 3.4% for adenocarcinoma. Adenoma incidence (4.9% in subjects under 50, 14.7% in those aged 50 to 75, and 16.4% in those older than 75, p<0.0001) and size (6.3mm in subjects younger than 50, 9.2mm in those 50 to 75 and 10.8mm in those older than 75, p=0.015) significantly increased with age. Adenoma incidence increased in the second period (14.8% vs. 10.3%, p=0.005), while adenoma size decreased in the second period (8.4mm vs. 10mm, p=0.006). There were no procedure related complications.Conclusions: The neoplasia detection rate was 16% (12.6% adenoma, 3.4% adenocarcinoma). Adenoma incidence and size increased with age in both cohorts. In the second screening period significantly more and smaller adenomas were detected.

Bobcats Exhibit Low Detection Rates at Hair Collection Stations in East Texas

2011 ◽  
Vol 7 (1) ◽  
Author(s):  
Christopher Eden Comer ◽  
Matthew E. Symmank ◽  
James C. Kroll
Keyword(s):  
East Texas ◽  
Detection Rates

Declining Detection Rates for APC and Biallelic MUTYH Pathogenic Variants in Polyposis Patients, Implications for DNA Testing Policy

2019 ◽  
Author(s):  
Diantha Terlouw ◽  
Manon Suerink ◽  
Sunny Singh ◽  
J. T. van Wezel ◽  
J. J. P. Gille ◽  
...  
Keyword(s):  
Dna Testing ◽  
Detection Rates ◽  
Pathogenic Variants

The Use of Bayesian Hierarchical Methods to Assess Selection and Observer Bias in Observational Health Outcome Studies

2006 ◽  
Author(s):  
Mark Ratcliffe ◽  
Josep Maria Haro ◽  
Stathis Kontodimas ◽  
Miguel Angel Negrin ◽  
David Suarez ◽  
...  
Keyword(s):  
Health Outcome ◽  
Outcome Studies ◽  
Observer Bias ◽  
Bayesian Hierarchical ◽  
Bayesian Hierarchical Methods
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