A modified dose-response model that describes the relationship between haemagglutination inhibition titre and protection against influenza infection

2017 ◽  
Vol 124 (1) ◽  
pp. 294-301 ◽  
Author(s):  
Y. Huang ◽  
S.A. Anderson ◽  
R.A. Forshee ◽  
H. Yang
Keyword(s):  
Dose Response ◽  
Influenza Infection ◽  
Haemagglutination Inhibition ◽  
Response Model ◽  
The Relationship

Use of a General Dose–Response Model for Rockfish Fecundity–Length Relationships

1990 ◽  
Vol 47 (6) ◽  
pp. 1148-1156 ◽  
Author(s):  
Laura J. Richards ◽  
Jon T. Schnute
Keyword(s):  
Dose Response ◽  
Regression Models ◽  
Data Sets ◽  
Response Model ◽  
Exact Inference ◽  
Special Cases ◽  
Wide Range ◽  
Length Data ◽  
The Relationship ◽  
General Method

In this paper we describe a general method for determining the relationship between fecundity and another fish attribute, such as size or age. Our methods include linear and logarithmic regression models as special cases and are applicable to a wide range of situations. The model we propose is based on the univariate form of the Schnute–Jensen dose–response model. However, we extend the Schnute–Jensen analysis by describing exact inference regions obtained from likelihood contours, to which we assign nominal probability levels. We also provide a method for obtaining an inference band for the predicted curve. We examine the issue of model adequacy as it relates to fecundity–length data from two rockfish (Sebastes) species. We show that the extra complexity of our model is justified, as none of the traditional regression models are appropriate for all three of our data sets. Further, we use inference bands to distinguish fecundity–length relationships for quillback rockfish (S. maliger) from two areas, but we are unable to distinguish one of these relationships from a similar relationship for copper rockfish (S. caurinus).

scholarly journals Estimating the tolerance of brachial plexus to hypofractionated stereotactic body radiotherapy: a modelling-based approach from clinical experience

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Irina Kapitanova ◽  
Sharmi Biswas ◽  
Sabrina Divekar ◽  
Eric J. Kemmerer ◽  
Robert A. Rostock ◽  
...  
Keyword(s):  
Brachial Plexus ◽  
Dose Response ◽  
Medical Center ◽  
Probit Model ◽  
Brachial Plexopathy ◽  
Maximum Point ◽  
Response Model ◽  
Clinical Practices ◽  
Karolinska Institute ◽  
Human Dose

Abstract Background Brachial plexopathy is a potentially serious complication from stereotactic body radiation therapy (SBRT) that has not been widely studied. Therefore, we compared datasets from two different institutions and generated a brachial plexus dose–response model, to quantify what dose constraints would be needed to minimize the effect on normal tissue while still enabling potent therapy for the tumor. Methods Two published SBRT datasets were pooled and modeled from patients at Indiana University and the Richard L. Roudebush Veterans Administration Medical Center from 1998 to 2007, as well as the Karolinska Institute from 2008 to 2013. All patients in both studies were treated with SBRT for apically located lung tumors localized superior to the aortic arch. Toxicities were graded according to Common Terminology Criteria for Adverse Events, and a probit dose response model was created with maximum likelihood parameter fitting. Results This analysis includes a total of 89 brachial plexus maximum point dose (Dmax) values from both institutions. Among the 14 patients who developed brachial plexopathy, the most common complications were grade 2, comprising 7 patients. The median follow-up was 30 months (range 6.1–72.2) in the Karolinska dataset, and the Indiana dataset had a median of 13 months (range 1–71). Both studies had a median range of 3 fractions, but in the Indiana dataset, 9 patients were treated in 4 fractions, and the paper did not differentiate between the two, so our analysis is considered to be in 3–4 fractions, one of the main limitations. The probit model showed that the risk of brachial plexopathy with Dmax of 26 Gy in 3–4 fractions is 10%, and 50% with Dmax of 70 Gy in 3–4 fractions. Conclusions This analysis is only a preliminary result because more details are needed as well as additional comprehensive datasets from a much broader cross-section of clinical practices. When more institutions join the QUANTEC and HyTEC methodology of reporting sufficient details to enable data pooling, our field will finally reach an improved understanding of human dose tolerance.

Underestimation of Dose - Response Relationship with Particular Reference to the Relationship between the Dietary Intake of Mercury and its Concentration in Blood

1988 ◽  
Vol 7 (2) ◽  
pp. 129-132 ◽  
Author(s):  
J.C. Sherlock ◽  
M.J. Quinn
Keyword(s):  
Linear Regression ◽  
Dietary Intake ◽  
Dose Response ◽  
Mercury Concentration ◽  
Response Relationship ◽  
Dose Response Relationship ◽  
Blood Mercury ◽  
Relationship Of ◽  
The Relationship ◽  
Blood Mercury Concentration

Wide discrepancies have been observed between controlled and uncontrolled intake studies of the relationship of blood mercury concentration to intake of mercury. The probable reason for the apparent discrepancies is that the within-subject variation of mercury intake in the uncontrolled studies was almost certainly considerably larger than the within-subject variation in blood mercury concentration; in these circumstances, the apparent slope obtained from a linear regression of blood mercury on intake will invariably be much smaller than the true slope. Studies of the exposure or intake of any substance should therefore include a consideration of the likely within-subject variation in the exposure or intake relative to that in the effect.

scholarly journals Association of psychiatric comorbidities with the risk of transport accidents in ADHD and MPH

2021 ◽  
Vol 30 ◽  
Author(s):  
Yi-Chun Liu ◽  
Vincent Chin-Hung Chen ◽  
Yao-Hsu Yang ◽  
Yi-Lung Chen ◽  
Michael Gossop
Keyword(s):  
Dose Response ◽  
Case Series ◽  
Autism Spectrum ◽  
Research Database ◽  
Accident Risk ◽  
Response Relationship ◽  
Dose Response Relationship ◽  
Series Analysis ◽  
The Relationship ◽  
Transport Accidents

Abstract Aims Although the relationship between attention-deficit/hyperactivity disorder (ADHD) and transport accidents has been shown, there is limited information on the relationship between medication and dose–response effects and transport accident risk. This study aims to determine whether young people with ADHD, including adolescents, are more prone to transport accidents than those without, and the extent to which methylphenidate (MPH) prescription in these patients reduces the risk. Methods We identified 114 486 patients diagnosed with ADHD from Taiwan's National Health Insurance Research Database from 1997 to 2013. Using a Cox regression model, we compared the risk of transport accidents between ADHD and non-ADHD groups and estimated the effect of MPH on accidents. Furthermore, we applied a self-control case-series analysis to compare the risk of accidents during the medication periods with the same patients' non-medication periods. Results Male ADHD patients had a higher risk of transport accidents than non-ADHD individuals (adjusted hazard ratio [aHR] = 1.24, [95% confidence interval (CI) 1.10–1.39]), especially for those comorbid with epilepsy, oppositional defiant disorder/conduct disorder (ODD/CD), and intellectual disabilities (ID). Female ADHD patients showed no relationship, except for comorbid with autism spectrum disorder (ASD) or ID. We found a reduced risk of transport accidents in patients with ADHD with MPH medication than those without MPH, with a plausible dose–response relationship (aHR of 0.23 to 0.07). A similar pattern was found in self-controlled case-series analysis. Conclusions Male patients with ADHD, especially those comorbid with epilepsy, ODD/CD, or ID, were at high risk of transport accidents. Female patients, when comorbid with ASD or ID, also exhibited a higher risk of accidents. MPH treatment lowered the accident risk with a dose–response relationship.

Statistical characterization of the random errors in the radioimmunoassay dose--response variable.

1976 ◽  
Vol 22 (3) ◽  
pp. 350-358 ◽  
Author(s):  
D Rodbard ◽  
R H Lenox ◽  
H L Wray ◽  
D Ramseth
Keyword(s):  
Least Squares ◽  
Dose Response ◽  
Curve Fitting ◽  
Response Curve ◽  
Dose Response Curve ◽  
Random Errors ◽  
Statistical Characterization ◽  
Response Variable ◽  
Least Squares Curve Fitting ◽  
The Relationship

Abstract We have developed practical methods for evaluating the magnitude of the random errors in radioimmunoassay dose--response variables, and the relationship between this error and position on the dose--response curve. This is important: to obtain appropriate weights for each point on the dose--response curve when utilizing least-squares curve-fitting methods; to evaluate whether the standards and the unknowns are subject to error of the same magnitude; for quality-control purposes; and to study the sources of errors in radioimmunoassay. Both standards and unknowns in radioimmunoassays for cAMP and cGMP were analyzed in triplicate. The same mean (Y), sample standard deviation, sy, and variance (2-y) of the response variable were calculated for each dose level. The relationship between s 2-y and y was calculated utilizing several models. Results for standards and unknowns from several assays were pooled, and a curve smoothing procedure was used to minimize random sampling errors. This pooling increased the reliability of the analysis, and confirmed the presence of the theoretically predicted nonuniformity of variance. Thus, the calculation of results from these radioimmunoassays should utilize a weighted least-squares curve-fitting program. These analyses have been computerized, and can be used as a "pre-processor" for programs for routine analysis of results of radioimmunoassay.

Changes in Post-Traumatic Symptom Pattern during and after Exposure to Extreme War Stress: An Uncontrolled, Preliminary Study Supporting the Dose-Response Model

2010 ◽  
Vol 25 (1) ◽  
pp. 38-41 ◽  
Author(s):  
Menachem Ben-Ezra ◽  
Yuval Palgi ◽  
Amit Shrira ◽  
Dina Sternberg ◽  
Nir Essar
Keyword(s):  
Dose Response ◽  
Medical Center ◽  
External Stress ◽  
Response Model ◽  
Ptsd Symptoms ◽  
Post Traumatic Stress ◽  
War Stress ◽  
Symptom Pattern ◽  
Post Traumatic ◽  
Stress Influences

AbstractIntroduction:Exposure to prolonged war stress is understudied. While there is debate regarding the empirical data of the dose-response model for post-traumatic stress disorder (PTSD), little is known about how weekly changes in external stress influences the level of PTSD symptoms. The purpose of this study was to measure the relation between objective external stress and PTSD symptoms across time, and thus, gain a deeper understating of the dose-response model.Hypothesis:The study hypothesis postulates that the more severe the external stressor, the more severe the exhibition of traumatic symptoms.Methods:Thirteen special army administrative staff (SAAS) members from the Rambam Medical Center in Haifa attended seven intervention meetings during the war. These personnel answered a battery of questionnaires regarding demographics and PTSD symptoms during each session. A non-parametric test was used in order to measure the changes in PTSD symptoms between sessions. Pearson correlations were used in order to study the relationship between the magnitude of external stressors and the severity of PTSD symptoms.Results:The results suggested that there was a significant relationship between the magnitude of external stressors and the severity of PTSD symptoms. These results are in line with the dose-response model.Conclusions:The results suggest that a pattern of decline in PTSD symptoms confirm the dose-response model for PTSD.

scholarly journals On use of the multistage dose–response model for assessing laboratory animal carcinogenicity

2007 ◽  
Vol 48 (2) ◽  
pp. 135-147 ◽  
Author(s):  
Daniela K. Nitcheva ◽  
Walter W. Piegorsch ◽  
R.Webster West
Keyword(s):  
Dose Response ◽  
Laboratory Animal ◽  
Response Model

scholarly journals Radiation dose-response (a Bayesian model) in the radiotherapy of the localized prostatic adenocarcinoma: the reliability of PSA slope changes as a response surrogate endpoint

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7172
Author(s):  
Reza Ali Mohammadpour ◽  
Jamshid Yazdani- Charati ◽  
SZahra Faghani ◽  
Ahad Alizadeh ◽  
Mohammadreza Barzegartahamtan
Keyword(s):  
Radiation Dose ◽  
Dose Response ◽  
Specific Antigen ◽  
Surrogate Endpoint ◽  
Assessment System ◽  
T Stage ◽  
Kaplan Meier ◽  
Total Radiation Dose ◽  
Product Limit ◽  
The Relationship

Purpose One of the characteristics of Prostate-Specific Antigen (PSA) is PSA slope. It is the rate of diminishing PSA marker over time after radiotherapy (RT) in prostate cancer (PC) patients. The purpose of this study was to evaluate the relationship between increasing RT doses and PSA slope as a potential surrogate for PC recurrence. Patients and Methods This retrospective study was conducted on PC patients who were treated by radiotherapy in the Cancer Institute of Iran during 2007–2012. By reviewing the records of these patients, the baseline PSA measurement before treatment (iPSA), Gleason score (GS), clinical T stage (T. stage), and periodic PSA measurements after RT and the total radiation dose received were extracted for each patient separately. We used a Bayesian dose-response model, analysis of variance, Kruskal–Wallis test, Kaplan–Meier product-limit method for analysis. Probability values less 0.05 were considered statistically significant. Results Based on the D’Amico risk assessment system, 13.34% of patients were classified as “Low Risk”, 51.79% were “Intermediate Risk”, and 34.87% were “High Risk”. In terms of radiation doses, 12.31% of the patients received fewer than 50 Gy, 15.38% received 50 to 69 Gy, 61.03% received 70 Gy, and 11.28% received more than 70 Gy. The PSA values decreased after RT for all dose levels. The slope of PSA changes was negative for 176 of 195 patients. By increasing the dosage of radiation, the PSA decreased but these changes were not statistically significant (p = 0.701) and PSA slope as a surrogate end point cannot met the Prentice’s criteria for PC recurrence. Conclusion Significant changes in the dose-response relationship were not observed when the PSA slope was considered as the response criterion. Therefore, although the absolute value of the PSA decreased with increasing doses of RT, the relationship between PSA slope changes and increasing doses was not clear and cannot be used as a reliable response surrogate endpoint.

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