Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Institution
- Keyword
-
- Bayesian Clinical Trials (6)
- Bayesian Modeling in Health Care Services Research (4)
- Bayesian (3)
- Bayesian Psychometrics (3)
- Content validity (2)
-
- Exponential (2)
- Inverse gamma (2)
- MCMC (2)
- Prior elicitation (2)
- Robust Statistics (2)
- Sample size (2)
- ANOVA (1)
- Basketball (1)
- Bayesian analysis (1)
- Beta-Binomial (1)
- Beta; Binomial; Measure of location (1)
- Beta; Binomial; Mixture (1)
- Constrained modified L2 error • constrained nonlinear least squares • asymptotic inefficiency • robust factor analysis (1)
- Construct validity (1)
- Credible intervals (1)
- DEA (1)
- Data augmentation (1)
- Elicitation of priors (1)
- Factorial validity (1)
- Gibbs sampler (1)
- Gibbs sampler; censored data; hierarchical model; relative risk; data augmentation; (1)
- Healthcare efficiency (1)
- Hierarchical Model (1)
- IACCV (1)
- Informative Prior (1)
Articles 1 - 17 of 17
Full-Text Articles in Physical Sciences and Mathematics
On The Existence Of Constant Accrual Rates In Clinical Trials And Direction For Future Research, Byron J. Gajewski, Stephen D. Simon, Susan E. Carslon
On The Existence Of Constant Accrual Rates In Clinical Trials And Direction For Future Research, Byron J. Gajewski, Stephen D. Simon, Susan E. Carslon
Byron J Gajewski
Many clinical trials fall short of their accrual goals. This can be avoided with accurate accrual prediction tools. Past researchers provide important methodological alternative models for predicting accrual in clinical trials. One model allows for slow accrual at the start of the study, which eventually reaches a threshold. A simpler model assumes a constant rate of accrual. A comparison has been attempted but we wish to point out some important considerations when comparing these two models. In fact, we can examine the reasonableness of a constant accrual assumption (simpler model) which had data 239 days into a three- year study. …
Data Envelopment Analysis In The Presence Of Measurement Error: Case Study From The National Database Of Nursing Quality Indicators (Ndnqi), Byron J. Gajewski, Robert Lee, Nancy Dunton
Data Envelopment Analysis In The Presence Of Measurement Error: Case Study From The National Database Of Nursing Quality Indicators (Ndnqi), Byron J. Gajewski, Robert Lee, Nancy Dunton
Byron J Gajewski
Data envelopment analysis (DEA) is the most commonly used approach for evaluating healthcare efficiency [B. Hollingsworth, The measurement of efficiency and productivity of health care delivery. Health Economics 17(10) (2008), pp. 1107–1128], but a long-standing concern is that DEA assumes that data are measured without error. This is quite unlikely, and DEA and other efficiency analysis techniques may yield biased efficiency estimates if it is not realized [B.J. Gajewski, R. Lee, M. Bott, U. Piamjariyakul, and R.L. Taunton, On estimating the distribution of data envelopment analysis efficiency scores: an application to nursing homes’ care planning process. Journal of Applied Statistics …
Assessing Content Validity Through Correlation And Relevance Tools A Bayesian Randomized Equivalence Experiment, Byron J. Gajewski, Diane K. Boyle, Marjorie Bott, Larry R. Price, Jamie Leopold, Nancy Dunton
Assessing Content Validity Through Correlation And Relevance Tools A Bayesian Randomized Equivalence Experiment, Byron J. Gajewski, Diane K. Boyle, Marjorie Bott, Larry R. Price, Jamie Leopold, Nancy Dunton
Byron J Gajewski
Content validity elicits expert opinion regarding items of a psychometric instrument. Expert opinion can be elicited in many forms: for example, how essential an item is or its relevancy to a domain. This study developed an alternative tool that elicits expert opinion regarding correlations between each item and its respective domain. With 109 Registered Nurse (RN) site coordinators from National Database of Nursing Quality Indicators, we implemented a randomized Bayesian equivalence trial with coordinators completing ‘‘relevance’’ or ‘‘correlation’’ content tools regarding the RN Job Enjoyment Scale. We confirmed our hypothesis that the two tools would result in equivalent content information. …
Integrated Analysis Of Content And Construct Validity, Byron J. Gajewski, Larry R. Price, Valorie Coffland, Diane K. Boyle, Marjorie J. Bott
Integrated Analysis Of Content And Construct Validity, Byron J. Gajewski, Larry R. Price, Valorie Coffland, Diane K. Boyle, Marjorie J. Bott
Byron J Gajewski
Establishing adequacy of psychometric properties of an instrument involves acquisition and evaluation of evidence based on item content and internal structure. Content validity evidence consists of subject matter experts providing quantitative ratings of the extent to which items are a representative sample of targeted domain. Evidence of internal structure includes factor analytic studies and examination of item interrelationships based on item responses from participants. Although subject matter expert ratings and participant response data are traditionally analyzed separately, each serves to inform the other in important ways. We propose integrating subject matter experts’ and participants’ data seamlessly to establish a unified …
How A Bayesian Might Estimate The Distribution Of Cronbach’S Alpha From Ordinal-Dynamic Scaled Data A Case Study Measuring Nursing Home Resident Quality Of Life, Byron J. Gajewski, Diane K. Boyle, Sarah Thompson
How A Bayesian Might Estimate The Distribution Of Cronbach’S Alpha From Ordinal-Dynamic Scaled Data A Case Study Measuring Nursing Home Resident Quality Of Life, Byron J. Gajewski, Diane K. Boyle, Sarah Thompson
Byron J Gajewski
We demonstrate the utility of a Bayesian based approach for calculating intervals of Cronbach’s alpha from a psychological instrument having ordinal responses with a dynamic scale. A small number of response options on an instrument will cause traditional-based interval estimates to be biased. Ordinal-based solutions are problematic because there is no clear mechanism for handling the dynamic scale. One way to remedy the bias is to adjust with a Bayesian approach. The Bayesian approach adjusts the bias and allows theoretically simple calculations of Cronbach’s alpha and intervals. We demonstrate the calculations of the Bayesian approach while at the same time …
Predicting Hearing Threshold In Nonresponsive Subjects Using A Log-Normal Bayesian Linear Model In The Presence Of Left-Censored Covariates, Byron J. Gajewski, Nannette Nicholson, Judith E. Widen
Predicting Hearing Threshold In Nonresponsive Subjects Using A Log-Normal Bayesian Linear Model In The Presence Of Left-Censored Covariates, Byron J. Gajewski, Nannette Nicholson, Judith E. Widen
Byron J Gajewski
We provide a nontrivial example illustrating analysis of a Bayesian clinical trial. Many of the issues discussed in the article are emphasized in a recent Food and Drug Administration (FDA) guidance on use of Bayesian statistics in medical device clinical trials. Here we present a fully Bayesian data analysis for predicting hearing thresholds in subjects who cannot respond to usual hearing tests. The article begins with simple concepts such as simple linear regression and proceeds into more complex issues such as censoring in the dependent and independent variables. Throughout, we emphasize the substantive interpretation of the analysis. Of particular interest …
A One-Hour Training Seminar On Bayesian Statistics For Nursing Graduate Students, Byron J. Gajewski, Stephen D. Simon
A One-Hour Training Seminar On Bayesian Statistics For Nursing Graduate Students, Byron J. Gajewski, Stephen D. Simon
Byron J Gajewski
In this paper we discuss one-way ANOVA with the goal of introducing Bayesian statistics to nursing graduate students in a one-hour seminar. We use ANOVA as it is arguably one of the most widely used statistical models in practice, and that its Bayesian treatment has interesting ties to the classical ANOVA, creating a smooth transition for students in a frequentist-based course to be introduced to Bayesian ideas. We discuss the limitations of this seminar in the context of our assumptions of what the students can or cannot do. An example from nursing research is used throughout the seminar.
Inter-Rater Reliability Of Pressure Ulcer Staging: Ordinal Probit Bayesian Hierarchical Model That Allows For Uncertain Rater Response, Byron J. Gajewski, Sara Hart, Sandra Bergquist-Beringer , Nancy Dunton
Inter-Rater Reliability Of Pressure Ulcer Staging: Ordinal Probit Bayesian Hierarchical Model That Allows For Uncertain Rater Response, Byron J. Gajewski, Sara Hart, Sandra Bergquist-Beringer , Nancy Dunton
Byron J Gajewski
This article describes a method for estimating the inter-rater reliability of pressure ulcer (PU) staging (stages I-IV) from raters in National Database of Nursing Quality Indicators (NDNQI) participating hospitals. The method models ordinal spanning data utilizing an ordinal probit Bayesian hierarchical model (BHM) across several hospitals in which raters monitor patient's PUs. An ulcer that cannot be accurately assessed because the base of the wound cannot be seen is defined as unstageable. Our novel approach allows for an unstageable PU rating to be included in the analysis. We compare the ordinal probit BHM to an approximate random-effects (standard approach in …
Predicting Accrual In Clinical Trials With Bayesian Posterior Predictive Distributions, Byron J. Gajewski, Stephen Simon, Susan Carlson
Predicting Accrual In Clinical Trials With Bayesian Posterior Predictive Distributions, Byron J. Gajewski, Stephen Simon, Susan Carlson
Byron J Gajewski
Investigators need good statistical tools for the initial planning and for the ongoing monitoring of clinical trials. In particular, they need to carefully consider the accrual rate - how rapidly patients are being recruited into the clinical trial. A slow accrual decreases the likelihood that the research will provide results at the end of the trial with sufficient precision (or power) to make meaningful scientific inferences. In this paper, we present a method for predicting accrual. Using a Bayesian framework we combine prior information with the information known up to a monitoring point to obtain a prediction. We provide posterior …
Bayesian Sample Size Calculations In Phase Ii Clinical Trials Using A Mixture Of Informative Priors., Byron J. Gajewski, Matthew S. Mayo
Bayesian Sample Size Calculations In Phase Ii Clinical Trials Using A Mixture Of Informative Priors., Byron J. Gajewski, Matthew S. Mayo
Byron J Gajewski
A number of researchers have discussed phase II clinical trials from a Bayesian perspective. A recent article by Mayo and Gajewski focuses on sample size calculations, which they determine by specifying an informative prior distribution and then calculating a posterior probability that the true response will exceed a prespecified target. In this article, we extend these sample size calculations to include a mixture of informative prior distributions. The mixture comes from several sources of information. For example consider information from two (or more) clinicians. The first clinician is pessimistic about the drug and the second clinician is optimistic. We tabulate …
Non-Normal Path Analysis In The Presence Of Measurement Error And Missing Data: A Bayesian Analysis Of Nursing Homes' Structure And Outcomes, Byron J. Gajewski, Robert Lee, Sarah Thomspn, Dunton Nancy, Annette Becker, Valorie Coffland
Non-Normal Path Analysis In The Presence Of Measurement Error And Missing Data: A Bayesian Analysis Of Nursing Homes' Structure And Outcomes, Byron J. Gajewski, Robert Lee, Sarah Thomspn, Dunton Nancy, Annette Becker, Valorie Coffland
Byron J Gajewski
Path analytic models are useful tools in quantitative nursing research. They allow researchers to hypothesize causal inferential paths and test the significance of these paths both directly and indirectly through a mediating variable. A standard statistical method in the path analysis literature is to treat the variables as having a normal distribution and to estimate paths using several least squares regression equations. The parameters corresponding to the direct paths have point and interval estimates based on normal distribution theory. Indirect paths are a product of the direct path from the independent variable to the mediating variable and the direct path …
Inter-Rater Reliability Of Nursing Home Surveys: A Bayesian Latent Class Approach, Byron J. Gajewski, Sarah Thompson, Nancy Dunton, Annette Becker, Marcia Wrona
Inter-Rater Reliability Of Nursing Home Surveys: A Bayesian Latent Class Approach, Byron J. Gajewski, Sarah Thompson, Nancy Dunton, Annette Becker, Marcia Wrona
Byron J Gajewski
In the U.S., federal and state governments perform routine inspections of nursing homes. Results of the inspections allow government to generate nes for ndings of non-compliance as well as allow consumers to rank facilities. The purpose of this study is to investigate the inter-rater reliability of the nursing home survey process. In general, the survey data involves 191 binary deciency variables interpreted as ‘decient’ or ‘non-decient’. To reduce the dimensionality of the problem, our proposed method involves two steps. First, we reduce the deciency categories to sub-categories using previous nursing home studies. Second, looking at the State of Kansas specically, …
Bayesian Sample Size Calculations In Phase Ii Clinical Trials Using Using Informative Conjugate Priors, Matthew S. Mayo, Byron J. Gajewski
Bayesian Sample Size Calculations In Phase Ii Clinical Trials Using Using Informative Conjugate Priors, Matthew S. Mayo, Byron J. Gajewski
Byron J Gajewski
A number of researchers have discussed phase II clinical trials from a Bayesian perspective. A recent article by Tan and Machin focuses on sample size calculations, which they determine by specifying a diffuse prior distribution and then calculating a posterior probability that the true response will exceed a prespecified target. In this article, we extend these sample size calculations to include informative prior distributions using various strategies that allow researchers with both optimistic and pessimistic priors direct involvement in the sample size decision making. We select the informative priors via multiple methods determined by the mean, median or mode of …
Correspondence Estimation Of The Source Profiles In Receptor Modeling, Byron J. Gajewski, Clifford H. Spiegelman
Correspondence Estimation Of The Source Profiles In Receptor Modeling, Byron J. Gajewski, Clifford H. Spiegelman
Byron J Gajewski
This article considers the estimation of source profiles from pollution data collected at one receptor site. At this receptor site, varying metrological conditions can cause errors that are possibly a mixture of distributions. A standard estimator utilizes a least squares approach because of its optimal properties under normally distributed errors and consistency under many other distributions. In contrast, we study the behavior of least squares relative to our new approach, which is better suited for dealing with errors having a mixture of distributions. The estimator loses efficiency under normal errors, but in turn gains efficiency while in the presence of …
Drafting A Career In Sports: Determining Underclassmen College Players’ Stock In The Nba Draft, Byron J. Gajewski, Todd Bishop
Drafting A Career In Sports: Determining Underclassmen College Players’ Stock In The Nba Draft, Byron J. Gajewski, Todd Bishop
Byron J Gajewski
No abstract provided.
A Log-Normal Distribution Model Of The Effect Of Bacteria And Ear Fenestration On Hearing Loss: A Bayesian Approach, Byron J. Gajewski, Jack D. Sedwick, Patrick J. Antonelli
A Log-Normal Distribution Model Of The Effect Of Bacteria And Ear Fenestration On Hearing Loss: A Bayesian Approach, Byron J. Gajewski, Jack D. Sedwick, Patrick J. Antonelli
Byron J Gajewski
Chronic ear infection is a potentially life-threatening illness that medical doctors typically treat with ear surgery. Despite the success of this treatment, complications can occur due to bacteria infection. Surgeons believe that this infection causes the patient to have clinically signigcant hearing damage. In order to understand such complications, surgeons must quantify the effect of bacteria, their toxins and ear surgery on hearing loss. To this end, the other two authors of this paper performed two experiments on guinea pigs to measure hearing thresholds following a bacterial infection and surgery of the inner ear. The response variable in these experiments …
Robust Estimation Of Origin-Destination Matrices, Byron J. Gajewski, Laurence R Rilett, Michael P. Dixon, Clifford H. Spiegelman
Robust Estimation Of Origin-Destination Matrices, Byron J. Gajewski, Laurence R Rilett, Michael P. Dixon, Clifford H. Spiegelman
Byron J Gajewski
The demand for travel on a network is usually represented by an origin-destination (OD) trip table or matrix. OD trip tables are typically estimated with synthetic techniques that use observed data from the traffic system, such as link volume counts from intelligent transportation systems (ITS), as input. A potential problem with current estimation techniques is that many ITS volume counters have a relatively high error rate. The focus of this paper is on the development of estimators explicitly designed to be robust to outliers typically encountered in ITS. Equally important, standard errors are developed so that the parameter reliability can …