1
|
Affiliation(s)
- Abdel-Salam Gomaa
- Department of Mathematics, Statistics and Physics College of Arts and Sciences, Qatar University, Doha, Qatar
| | - Jeffrey B. Birch
- Department of Statistics, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| |
Collapse
|
2
|
Cole CC, Carnell SC, Jiwa KJ, Birch JB, Hester KH, Ward CW, Simpson JS, Soyza ADSD. S46 Neutrophil vascular endothelial growth factor (VEGF) as a driving force for angiogenesis in bronchiectasis? Thorax 2016. [DOI: 10.1136/thoraxjnl-2016-209333.52] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
3
|
Wan W, Pei XY, Grant S, Birch JB, Felthousen J, Dai Y, Fang HB, Tan M, Sun S. Nonlinear response surface in the study of interaction analysis of three combination drugs. Biom J 2016; 59:9-24. [PMID: 27185067 DOI: 10.1002/bimj.201500021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 12/14/2015] [Accepted: 12/24/2015] [Indexed: 02/05/2023]
Abstract
Few articles have been written on analyzing three-way interactions between drugs. It may seem to be quite straightforward to extend a statistical method from two-drugs to three-drugs. However, there may exist more complex nonlinear response surface of the interaction index (II) with more complex local synergy and/or local antagonism interspersed in different regions of drug combinations in a three-drug study, compared in a two-drug study. In addition, it is not possible to obtain a four-dimensional (4D) response surface plot for a three-drug study. We propose an analysis procedure to construct the dose combination regions of interest (say, the synergistic areas with II≤0.9). First, use the model robust regression method (MRR), a semiparametric method, to fit the entire response surface of the II, which allows to fit a complex response surface with local synergy/antagonism. Second, we run a modified genetic algorithm (MGA), a stochastic optimization method, many times with different random seeds, to allow to collect as many feasible points as possible that satisfy the estimated values of II≤0.9. Last, all these feasible points are used to construct the approximate dose regions of interest in a 3D. A case study with three anti-cancer drugs in an in vitro experiment is employed to illustrate how to find the dose regions of interest.
Collapse
Affiliation(s)
- Wen Wan
- Department of Biostatistics, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Xin-Yan Pei
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Steven Grant
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Jeffrey B Birch
- Department of Statistics, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Jessica Felthousen
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Yun Dai
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Hong-Bin Fang
- Department of Statistics, Georgetown University, Washington, DC 20057, USA
| | - Ming Tan
- Department of Statistics, Georgetown University, Washington, DC 20057, USA
| | - Shumei Sun
- Department of Biostatistics, Virginia Commonwealth University, Richmond, VA 23298, USA
| |
Collapse
|
4
|
Williams JD, Birch JB, Abdel-Salam ASG. Outlier robust nonlinear mixed model estimation. Stat Med 2015; 34:1304-16. [DOI: 10.1002/sim.6406] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 12/04/2014] [Accepted: 12/11/2014] [Indexed: 11/11/2022]
Affiliation(s)
- James D. Williams
- Business Analytics; Dow AgroSciences; 9330 Zionsville Rd. Indianapolis IN 46268 U.S.A
| | - Jeffrey B. Birch
- Department of Statistics; Virginia Polytechnic Institute and State University; Blacksburg VA 24061-0439 U.S.A
| | - Abdel-Salam G. Abdel-Salam
- Department of Mathematics, Statistics and Physics, College of Arts and Sciences; Qatar University; Doha Qatar
| |
Collapse
|
5
|
|
6
|
Bollinger GA, Davison FC, Sibol MS, Birch JB. Magnitude recurrence relations for the southeastern United States and its subdivisions. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/jb094ib03p02857] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
7
|
|
8
|
|
9
|
Woodall WH, Birch JB, Du P. Comment. Technometrics 2010. [DOI: 10.1198/tech.2010.09165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
10
|
Williams JD, Sullivan JH, Birch JB. Maximum Value of Hotelling's T2Statistics Based on the Successive Differences Covariance Matrix Estimator. COMMUN STAT-THEOR M 2009. [DOI: 10.1080/03610920802233952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
11
|
|
12
|
|
13
|
|
14
|
|
15
|
Birch JB, Foutz RV. An algorithm for computing a two-sample test based on empirical probability measures. COMMUN STAT-SIMUL C 2007. [DOI: 10.1080/03610918508812437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
16
|
Doris B, Birch JB. Estimation of regression coefficients under model misspecification and non-normality of errors. J STAT COMPUT SIM 2007. [DOI: 10.1080/00949658408810724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
17
|
|
18
|
|
19
|
Sarmadi AM, Noel CJ, Birch JB. Effects of heat treatment on dyeability, glass transition temperature, and tensile properties of polyacrylonitrile fibers. Ind Eng Chem Res 2002. [DOI: 10.1021/ie00104a011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
20
|
|
21
|
|
22
|
|
23
|
|
24
|
Abstract
In the analysis of a quantal dose-response experiment with grouped data, the most commonly used parametric procedure is logistic regression, commonly referred to as 'logit analysis'. The adequacy of the fit by the logistic regression curve is tested using the chi-square lack-of-fit test. If the lack-of-fit test is not significant, then the logistic model is assumed to be adequate and estimation of effective doses and confidence intervals on the effective doses can be made. When the tolerance distribution of the dose-response data is not known and cannot be assumed by the user, one can use non-parametric methods, such as kernel regression or local linear regression, to estimate the dose-response curve, effective doses and confidence intervals. This research proposes another alternative based on semi-parametric regression to analysing quantal dose-response data called model-robust quantal regression (MRQR). MRQR linearly combines the parametric and non-parametric predictions with the use of a mixing parameter. MRQR uses logistic regression as the parametric portion of the model and local linear regression as the non-parametric portion of the model. Our research has shown that the MRQR procedure can improve the fit of the dose-response curve by producing narrower confidence intervals for predictions while providing improved precision of estimates of the effective doses with respect to either logistic or local linear regression results.
Collapse
Affiliation(s)
- Q J Nottingham
- Department of Management Science & Information Technology, Virginia Polytechnic Institute and State University, 1007 Pamplin Hall, Blacksburg, VA 24061-0235, USA
| | | |
Collapse
|
25
|
Abstract
The logistic regression procedure is a popular statistical method used when analyzing quantal dose-response data. However, logistic regression results based on a poorly designed experiment can be seriously compromised. Our results indicate that depending on the spacing of the doses, the number of doses, and the number of replications at each dose, the user can get very misleading results, including ineffective lack-of-fit tests and severely biased coefficient estimates along with biased estimates of response. In addition, variance formulas based on asymptotic theory may be completely inappropriate. Simulation results are used to support these statements.
Collapse
Affiliation(s)
- Q J Nottingham
- Department of Management Science and Information Technology, Virginia Polytechnic Institute and State University, Blacksburg 24061, USA
| | | |
Collapse
|
26
|
|
27
|
|
28
|
|
29
|
|
30
|
|
31
|
Abstract
Development of the interleukin 2(IL 2) microassay, coupled with the use of highly purified or recombinant factors has allowed a detailed examination of the mechanism of action of this important biological response modifier. However, probit analysis of the microassay data does not allow inherent error of the system to be approximated nor can units of activity be assessed for significance. A computer program was developed to analyze the validity of each regression line and to generate 95% confidence intervals around each line. This program employs analysis of variance, linear regression analysis and the parallel line assay to fix confidence intervals for each IL 2 unit value. The use of recombinant IL 2 as an immunomodulator in clinical settings warrants a more precise statistical method to evaluate normal fluctuations of this factor than currently in use. The development of such a method is presented here.
Collapse
|
32
|
Birch JB, Foutz RV. Selected percent points for a test for the two-sample problem based on empirical probability measures. COMMUN STAT-SIMUL C 1984. [DOI: 10.1080/03610918408812383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
33
|
|
34
|
Birch JB, Myers RH. Robust analysis of covariance. Biometrics 1982; 38:699-713. [PMID: 6756495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The simple analysis of covariance situation with two groups and one concomitant variable is considered. The parameters of this model with outliers present are estimated by the methods of at least squares and M-estimation. By use of simulation, several forms of M-estimators are compared with the least squares method. In terms of their efficiencies the tests on the equality of slopes and of adjusted means in the presence of outliers are examined under the null hypothesis by studying the behavior of t-like statistics based on the least squares and M-estimates. An example illustrates the techniques discussed.
Collapse
|
35
|
|
36
|
Birch JB, McNeil DR. Interactive Data Analysis. J Am Stat Assoc 1978. [DOI: 10.2307/2286301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|