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Ball G, Li M, Buchanan J, Hendrickson B, Zink RC, Snapinn S, Herson J. Aggregate IND Safety Reporting for Smaller Companies and Programs. Ther Innov Regul Sci 2024; 58:368-379. [PMID: 38190028 DOI: 10.1007/s43441-023-00605-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Accepted: 12/01/2023] [Indexed: 01/09/2024]
Abstract
The United States (US) Food and Drug Administration (FDA) Investigational New Drug (IND) Final Rule (US FDA, Final rule: Investigational new drug safety reporting requirements for human drug and biological products and safety reporting requirements for bioavailability and bioequivalence studies in humans, 2010) applies to all human drugs and biological products being studied under an IND. The Final Rule specifies that a sponsor must file an IND safety report for any Suspected Unexpected Serious Adverse Reaction (SUSAR) of a medicinal product being investigated. To make a proper SUSAR classification, sponsors need to go beyond conventional Data Monitoring Committees (DMCs) with an interdisciplinary effort, using all relevant data (including data outside clinical trials), to make judgments on the possibility of serious adverse events being caused by the study drug-rather than the underlying condition of the patient or a concomitant therapy. Ball et al. (Ball et al. in Ther Innov Regul Sci 55:705-716, 2021) have reported on how the Final Rule has been implemented by large pharmaceutical companies. This paper explores the experiences of small sponsor companies regarding the Final Rule, to understand the current challenges that they have been facing to meet aggregate IND safety reporting requirements.
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Affiliation(s)
| | | | | | | | | | | | - Jay Herson
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
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Sall K, Foulks GN, Pucker AD, Ice KL, Zink RC, Magrath G. Validation of a Modified National Eye Institute Grading Scale for Corneal Fluorescein Staining. Clin Ophthalmol 2023; 17:757-767. [PMID: 36915716 PMCID: PMC10007867 DOI: 10.2147/opth.s398843] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [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: 11/23/2022] [Accepted: 02/10/2023] [Indexed: 03/09/2023] Open
Abstract
Purpose Validation of the novel Lexitas modified NEI scale for use in assessment of corneal fluorescein staining. Patients and Methods A series of 18 illustrations and 14 clinical photographs depicting varying severity levels of corneal fluorescein staining were assessed by 3 independent examiners. Regions of the cornea were graded for staining severity based on 3 different grading scales: the original NEI staining scale (density-based scoring; 0-3 scale), a structured version of the NEI scale (dot-count scoring; 0-3 scale), and the Lexitas modified NEI staining scale (0-4 scale with half-point increments). Kappa statistics (simple and weighted) were computed to determine intra-examiner image grading repeatability for each examiner over 2 separate assessments. Inter-examiner assessment reliability utilized the scores from the first read of each examiner, and pairs of examiners to compute kappa statistics. Results Data was analyzed from the scores provided by the examiners from each gradable corneal region on 32 images (18 illustrations and 14 photographs) for a total of 154 corneal regions across the 3 grading scales for each validation run. The mean intra-examiner simple/weighted kappa values using the NEI density, NEI dot count, and the Lexitas modified NEI staining scales were 0.67/0.72, 0.91/0.94, 0.80/0.92 for the graded illustrations, and 0.83/0.88, 0.76/0.85, 0.77/0.88 for the graded photographs, respectively. The mean inter-examiner simple/weighted kappa values using the NEI density, NEI dot count, and the Lexitas modified NEI staining scales were 0.59/0.65, 0.86/0.90, and 0.78/0.91 for the graded illustrations, and 0.80/0.88, 0.84/0.89, 0.69/0.88 for the graded photographs, respectively. Conclusion The expanded scale of the Lexitas modified NEI staining scale demonstrated a high degree of reliability and repeatability of grading assessments within and across individual examiners, comparing favorably with the original NEI staining scale. A future investigation into the in-office utility of the Lexitas modified NEI staining scale is warranted.
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Affiliation(s)
| | - Gary N Foulks
- University of Louisville (Retired), Louisville, KY, USA
| | | | - Karen L Ice
- Lexitas Pharma Services, Inc, Durham, NC, USA
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Shing TL, Preisser JS, Zink RC. GEECORR: A SAS macro for regression models of correlated binary responses and within-cluster correlation using generalized estimating equations. Comput Methods Programs Biomed 2021; 208:106276. [PMID: 34325377 DOI: 10.1016/j.cmpb.2021.106276] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 07/02/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND AND OBJECTIVES Generalized estimating equations (GEE) provide population-averaged model inference for longitudinal and clustered outcomes via a generalized linear model for the effect of explanatory variables on the marginal mean, while intra-cluster correlations are ordinarily treated as nuisance parameters. Software to richly parameterize and conduct inference for complex correlation structures in the marginal modeling framework is scarce. METHODS A SAS macro, GEECORR, has been developed for the analysis of clustered binary data based on GEE to include additional estimating equations for modeling pairwise correlation between binary variates as a function of covariates. RESULTS We illustrate the macro in a surveillance study with repeated measures, a longitudinal study, and a study with biological clustering. CONCLUSIONS This article provides an overview of the GEE method consisting of a pair of estimating equations, describes the features and capabilities of the GEECORR macro including regression diagnostics and finite-sample bias-corrected covariance estimators, and demonstrates the macro usage for three studies.
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Affiliation(s)
- Tracie L Shing
- Department of Biostatistics, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7420, United States.
| | - John S Preisser
- Department of Biostatistics, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7420, United States.
| | - Richard C Zink
- Lexitas Pharma Services, Inc., Durham, NC 27701-2102, United States.
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Fried MW, Crawford JM, Mospan AR, Watkins SE, Munoz B, Zink RC, Elliott S, Burleson K, Landis C, Reddy KR, Brown RS. Reply to Roussel et al. Clin Infect Dis 2021; 72:e929. [PMID: 33086377 DOI: 10.1093/cid/ciaa1621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
| | | | | | | | - Breda Munoz
- TARGET PharmaSolutions, Inc, Durham, North Carolina, USA
| | - Richard C Zink
- TARGET PharmaSolutions, Inc, Durham, North Carolina, USA
| | - Sherry Elliott
- Elliott Health Information Pros, Inc, Cary, North Carolina, USA
| | - Kyle Burleson
- TARGET PharmaSolutions, Inc, Durham, North Carolina, USA
| | - Charles Landis
- Liver Care and Transplantation Services at University of Washington Medical Center, Seattle, Washington, USA
| | - K Rajender Reddy
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Robert S Brown
- Department of Medicine, Division of Gastroenterology and Hepatology, Weill Cornell Medicine Center for Liver Disease, New York, New York, USA
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Fried MW, Crawford JM, Mospan AR, Watkins SE, Munoz B, Zink RC, Elliott S, Burleson K, Landis C, Reddy KR, Brown RS. Patient Characteristics and Outcomes of 11 721 Patients With Coronavirus Disease 2019 (COVID-19) Hospitalized Across the United States. Clin Infect Dis 2021; 72:e558-e565. [PMID: 32856034 PMCID: PMC7499515 DOI: 10.1093/cid/ciaa1268] [Citation(s) in RCA: 79] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 08/24/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND As COVID-19 disseminates throughout the US, a better understanding of patient characteristics associated with hospitalization, morbidity and mortality in diverse geographic regions is essential. METHODS Hospital chargemaster data on adult patients with COVID-19 admitted to 245 hospitals across 38 states between February 15 and April 20, 2020 were assessed. Clinical course from admission through hospitalization to discharge or death was analyzed. RESULTS A total of 11,721 patients were included (majority were >60 years of age [59.9%] and male [53.4%]). Comorbidities included hypertension (46.7%), diabetes (27.8%), cardiovascular disease (18.6%), obesity (16.1%), and chronic kidney disease (12.2%). Mechanical ventilation was required by 1,967 patients (16.8%). Mortality among hospitalized patients was 21.4% and increased to 70.5% among those on mechanical ventilation. Male sex, older age, obesity, geographic region, and the presence of chronic kidney disease or preexisting cardiovascular disease were associated with an increased odds of mechanical ventilation. All aforementioned risk factors, with the exception of obesity, were associated with an increased odds of death (all p& 0.001). Many patients received investigational medications for treatment of COVID-19, including 48 patients on remdesivir and 4,232 on hydroxychloroquine. CONCLUSION This large observational cohort describes the clinical course and identifies factors associated with outcomes of hospitalized patients with COVID-19 across the US. These data can inform strategies to prioritize prevention and treatment for this disease.
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Affiliation(s)
| | | | | | | | - Breda Munoz
- TARGET PharmaSolutions Inc., Durham, North Carolina, USA
| | - Richard C Zink
- TARGET PharmaSolutions Inc., Durham, North Carolina, USA
| | - Sherry Elliott
- Elliott Health Information Pros Inc., Cary, North Carolina, USA
| | - Kyle Burleson
- TARGET PharmaSolutions Inc., Durham, North Carolina, USA
| | - Charles Landis
- Liver Care and Transplantation Services at University of Washington Medical Center, Seattle, Washington, USA
| | - K Rajender Reddy
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Robert S Brown
- Department of Medicine, Division of Gastroenterology and Hepatology, Weill Cornell Medicine Center for Liver Disease, New York, New York, USA
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Levenson M, He W, Chen J, Fang Y, Faries D, Goldstein BA, Ho M, Lee K, Mishra-Kalyani P, Rockhold F, Wang H, Zink RC. Biostatistical Considerations When Using RWD and RWE in Clinical Studies for Regulatory Purposes: A Landscape Assessment. Stat Biopharm Res 2021. [DOI: 10.1080/19466315.2021.1883473] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
| | - Weili He
- Global Medical Affairs Statistics, Data and Statistical Sciences, AbbVie, North Chicago, IL
| | - Jie Chen
- Overland Pharmaceuticals, Dover, DE
| | - Yixin Fang
- Global Medical Affairs Statistics, Data and Statistical Sciences, AbbVie, North Chicago, IL
| | - Douglas Faries
- Global Statistical Sciences, Eli Lilly & Company, Indianapolis, IN
| | - Benjamin A. Goldstein
- Department of Biostatistics & Bioinformatics, Duke University, Durham, NC
- Duke Clinical Research Institute, Duke University, Durham, NC
| | | | - Kwan Lee
- Statistics and Decision Sciences, Janssen Research and Development (retired), Spring House, PA
| | | | - Frank Rockhold
- Department of Biostatistics & Bioinformatics, Duke University, Durham, NC
- Duke Clinical Research Institute, Duke University, Durham, NC
| | - Hongwei Wang
- Global Medical Affairs Statistics, Data and Statistical Sciences, AbbVie, North Chicago, IL
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Cabrera R, Singal AG, Colombo M, Kelley R, Lee H, Mospan AR, Meyer T, Newell P, Parikh ND, Sangro B, Reddy KR, Watkins S, Zink RC, Di Bisceglie AM. A Real-World Observational Cohort of Patients with Hepatocellular Carcinoma: Design and Rationale for TARGET-HCC. Hepatol Commun 2021; 5:538-547. [PMID: 33681685 PMCID: PMC7917285 DOI: 10.1002/hep4.1652] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/20/2020] [Accepted: 11/05/2020] [Indexed: 12/30/2022] Open
Abstract
This study describes the design of the TARGET-hepatocellular carcinoma (HCC) cohort and descriptive characteristics of the patient population at diagnosis among those who were enrolled in the cohort across academic and community clinical centers. TARGET-HCC is a 5-year, longitudinal, observational cohort of patients with HCC receiving care in usual clinical practice. Redacted clinical information, obtained from medical records, captures the natural history and management of the disease, including the safety and efficacy of treatment interventions used in usual clinical practice. Patients can complete patient-reported outcome measures and provide biological specimens for future translational studies. The TARGET-HCC study includes adults with histologic, cytologic, or radiologic diagnosis of HCC from academic and community centers in both the United States and Europe. A total of 1,841 participants were enrolled between January 9, 2017, and July 23, 2019, at 67 sites in the United States and Europe. To date, the most common liver disease etiology in the cohort continues to be hepatitis C, although nearly half had a nonviral etiology, including alcohol-related liver disease or nonalcoholic steatohepatitis. Most included patients were diagnosed at an early stage (Barcelona Clinic Liver Cancer Stage [BCLC] 0/A), but only approximately one third underwent curative treatment. Systemic therapy has been used in 7.3% of enrolled patients, including 45.7% of those with BCLC stage C tumors. Conclusion: Overall, the TARGET-HCC cohort allows for the assessment of patient characteristics and investigation of new treatment paradigms and sequencing with existing agents as well as novel regimens for HCC.
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Affiliation(s)
| | - Amit G. Singal
- University of Texas Southwestern Medical CenterDallasTXUSA
| | - Massimo Colombo
- Center for Translational Research in Liver DiseaseHumanitas HospitalRozzanoItaly
| | - R. Kate Kelley
- University of California San FranciscoSan FranciscoCAUSA
| | - Hannah Lee
- Division of Gastroenterology, Hepatology and NutritionVirginia Commonwealth UniversityRichmondVAUSA
| | | | - Tim Meyer
- Royal Free Hospital and University College London Cancer InstituteUniversity College LondonLondonUnited Kingdom
| | | | - Neehar D. Parikh
- Division of Internal MedicineUniversity of MichiganAnn ArborMIUSA
| | - Bruno Sangro
- Department of Internal MedicineClinica Universidad de NavarraMadridSpain
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Affiliation(s)
- Rachel Silverman
- Department of Biostatistics, The University of North Carolina, Chapel Hill, NC
| | - Jason Fine
- Department of Biostatistics, The University of North Carolina, Chapel Hill, NC
| | | | - Anastasia Ivanova
- Department of Biostatistics, The University of North Carolina, Chapel Hill, NC
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Marchenko O, Russek-Cohen E, Levenson M, Zink RC, Krukas-Hampel MR, Jiang Q. Sources of Safety Data and Statistical Strategies for Design and Analysis: Real World Insights. Ther Innov Regul Sci 2018; 52:170-186. [DOI: 10.1177/2168479017739270] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Zink RC, Castro-Schilo L, Ding J. Understanding the influence of individual variables contributing to multivariate outliers in assessments of data quality. Pharm Stat 2018; 17:846-853. [PMID: 30259643 DOI: 10.1002/pst.1903] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [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: 03/19/2018] [Revised: 08/07/2018] [Accepted: 08/07/2018] [Indexed: 11/09/2022]
Abstract
Mahalanobis distance is often recommended to identify patients or clinical sites that are considered unusual in clinical trials. Patients extreme in one or more covariates may be considered outliers in that they reside some distance from the multivariate mean, which can be thought of as the center of the data cloud. Less often discussed, patients whose data are believed to be "too good to be true" are located near the centroid as inliers. In order to efficiently investigate these anomalies for potential lapses in data quality, it is important to understand how the individual variables contribute to each multivariate outlier. There is a lack of literature describing a reasonable workflow for identification of outliers and their subsequent investigation to understand how each variable contributes to an observation being considered extreme. We describe how to identify multivariate inliers and outliers, classify outliers according to varying levels of severity, and summarize the contributions of variables using principal components in a manner that is accessible to a wide audience with straightforward interpretation. We illustrate how numerous data visualizations, including Pareto plots, can facilitate further review even in studies containing numerous observations and variables. We illustrate these methodologies using data from a multicenter clinical trial.
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Affiliation(s)
- Richard C Zink
- TARGET PharmaSolutions; Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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Zink RC. Introduction to the Special Section for Sources of Safety Data and Statistical Strategies for Design and Analysis. Ther Innov Regul Sci 2018; 52:140. [PMID: 29714517 DOI: 10.1177/2168479018760813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Richard C Zink
- JMP Life Sciences, SAS Institute, Charlotte, North Carolina, USA
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Abstract
BACKGROUND The quality of data from clinical trials has received a great deal of attention in recent years. Of central importance is the need to protect the well-being of study participants and maintain the integrity of final analysis results. However, traditional approaches to assess data quality have come under increased scrutiny as providing little benefit for the substantial cost. Numerous regulatory guidance documents and industry position papers have described risk-based approaches to identify quality and safety issues. In particular, the position paper of TransCelerate BioPharma recommends defining risk thresholds to assess safety and quality risks based on past clinical experience. This exercise can be extremely time-consuming, and the resulting thresholds may only be relevant to a particular therapeutic area, patient or clinical site population. In addition, predefined thresholds cannot account for safety or quality issues where the underlying rate of observing a particular problem may change over the course of a clinical trial, and often do not consider varying patient exposure. METHODS In this manuscript, we appropriate rules commonly utilized for funnel plots to define a traffic-light system for risk indicators based on statistical criteria that consider the duration of patient follow-up. Further, we describe how these methods can be adapted to assess changing risk over time. Finally, we illustrate numerous graphical approaches to summarize and communicate risk, and discuss hybrid clinical-statistical approaches to allow for the assessment of risk at sites with low patient enrollment. RESULTS We illustrate the aforementioned methodologies for a clinical trial in patients with schizophrenia. CONCLUSIONS Funnel plots are a flexible graphical technique that can form the basis for a risk-based strategy to assess data integrity, while considering site sample size, patient exposure, and changing risk across time.
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Affiliation(s)
- Richard C Zink
- 1 JMP Life Sciences, SAS Institute Inc, Cary, NC, USA.,2 Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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Zink RC, Marchenko O, Sanchez-Kam M, Ma H, Jiang Q. Sources of Safety Data and Statistical Strategies for Design and Analysis: Clinical Trials. Ther Innov Regul Sci 2017; 52:141-158. [PMID: 29714519 DOI: 10.1177/2168479017738980] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND There has been an increased emphasis on the proactive and comprehensive evaluation of safety endpoints to ensure patient well-being throughout the medical product life cycle. In fact, depending on the severity of the underlying disease, it is important to plan for a comprehensive safety evaluation at the start of any development program. Statisticians should be intimately involved in this process and contribute their expertise to study design, safety data collection, analysis, reporting (including data visualization), and interpretation. METHODS In this manuscript, we review the challenges associated with the analysis of safety endpoints and describe the safety data that are available to influence the design and analysis of premarket clinical trials. RESULTS We share our recommendations for the statistical and graphical methodologies necessary to appropriately analyze, report, and interpret safety outcomes, and we discuss the advantages and disadvantages of safety data obtained from clinical trials compared to other sources. CONCLUSIONS Clinical trials are an important source of safety data that contribute to the totality of safety information available to generate evidence for regulators, sponsors, payers, physicians, and patients. This work is a result of the efforts of the American Statistical Association Biopharmaceutical Section Safety Working Group.
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Affiliation(s)
- Richard C Zink
- JMP Life Sciences, SAS Institute, 701 SAS Campus Drive, Cary, NC, 27513, USA. .,Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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Zink RC, Zhang W. Guest Editors’ Note. Stat Biopharm Res 2016. [DOI: 10.1080/19466315.2016.1189356] [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]
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Abstract
BACKGROUND Sample size calculations are an important part of the design of any clinical trial. These calculations ensure a sufficient number of patients to detect a clinically meaningful difference between 2 treatments with high probability (ie, power). Perhaps less-often discussed, the sample size exercise is important so that resources are not wasted studying too many observations to test a particular hypothesis. Since patients may be randomized to doses of a novel treatment with a limited safety profile, or a placebo which provides no therapeutic benefit, sample size calculations in clinical trials come with an ethical burden not experienced in many subject-matter areas. METHODS The sample size of a clinical trial should be determined using as much data as is available, over a range of assumptions, and with input from clinical colleagues. Graphical techniques are often utilized to summarize power and sample size calculations. In this manuscript, we propose the use of contour plots to better assess, report, and communicate the sensitivity of clinical trial design assumptions. RESULTS Through several examples, we illustrate that contour plots are applicable to binary, continuous, and time-to-event endpoints for a variety of study design scenarios. CONCLUSIONS Contour plots are a useful tool for the study team in designing clinical trials, and they can be included in study documents to better communicate the rationale for sample size for clinicians and regulators. Contour plots provide greater transparency as to the uncertainty of the currently available information, and can be useful in deciding whether to consider adaptive designs.
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Affiliation(s)
- Richard C Zink
- 1 JMP Life Sciences, SAS Institute Inc, Cary, North Carolina, USA.,2 Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Xiaotong Jiang
- 2 Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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Marchenko O, Jiang Q, Chakravarty A, Ke C, Ma H, Maca J, Russek-Cohen E, Sanchez-Kam M, C. Zink R, Chuang-Stein C. Evaluation and Review of Strategies to Assess Cardiovascular Risk in Clinical Trials in Patients with Type 2 Diabetes Mellitus. Stat Biopharm Res 2015. [DOI: 10.1080/19466315.2015.1077724] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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By K, Qaqish BF, Preisser JS, Perin J, Zink RC. ORTH: R and SAS software for regression models of correlated binary data based on orthogonalized residuals and alternating logistic regressions. Comput Methods Programs Biomed 2014; 113:557-568. [PMID: 24286728 DOI: 10.1016/j.cmpb.2013.09.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2012] [Revised: 08/28/2013] [Accepted: 09/24/2013] [Indexed: 06/02/2023]
Abstract
This article describes a new software for modeling correlated binary data based on orthogonalized residuals, a recently developed estimating equations approach that includes, as a special case, alternating logistic regressions. The software is flexible with respect to fitting in that the user can choose estimating equations for association models based on alternating logistic regressions or orthogonalized residuals, the latter choice providing a non-diagonal working covariance matrix for second moment parameters providing potentially greater efficiency. Regression diagnostics based on this method are also implemented in the software. The mathematical background is briefly reviewed and the software is applied to medical data sets.
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Affiliation(s)
- Kunthel By
- Department of Biostatistics, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA.
| | - Bahjat F Qaqish
- Department of Biostatistics, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA
| | - John S Preisser
- Department of Biostatistics, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA
| | - Jamie Perin
- Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, MD, USA
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Abstract
BACKGROUND Adverse event incidence analyses are a critical component for describing the safety profile of any new intervention. The results typically are presented in lengthy summary tables. For therapeutic areas where patients have frequent adverse events, analysis and interpretation are made more difficult by the sheer number and variety of events that occur. Understanding the risk in these instances becomes even more crucial. PURPOSE We describe a space-saving graphical summary that overcomes the limitations of traditional presentations of adverse events and improves interpretability of the safety profile. METHODS We present incidence analyses of adverse events graphically using volcano plots to highlight treatment differences. Data from a clinical trial of patients experiencing an aneurysmal subarachnoid hemorrhage are used for illustration. Adjustments for multiplicity are illustrated. RESULTS Color is used to indicate the treatment with higher incidence; bubble size represents the total number of events that occur in the treatment arms combined. Adjustments for multiple comparisons are displayed in a manner to indicate clearly those events for which the difference between treatment arms is statistically significant. Furthermore, adverse events can be displayed by time intervals, with multiple volcano plots or animation to appreciate changes in adverse event risk over time. Such presentations can emphasize early differences across treatments that may resolve later or highlight events for which treatment differences may become more substantial with longer follow-up. LIMITATIONS Treatment arms are compared in a pairwise fashion. CONCLUSIONS Volcano plots are space-saving tools that emphasize important differences between the adverse event profiles of two treatment arms. They can incorporate multiplicity adjustments in a manner that is straightforward to interpret and, by using time intervals, can illustrate how adverse event risk changes over the course of a clinical trial.
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Affiliation(s)
- Richard C Zink
- JMP Life Sciences, SAS Institute Inc., Cary, NC 27513, USA.
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Zink RC, Huang Q, Zhang LY, Bao WJ. Statistical and graphical approaches for disproportionality analysis of spontaneously-reported adverse events in pharmacovigilance. Chin J Nat Med 2013; 11:314-20. [PMID: 23725848 DOI: 10.1016/s1875-5364(13)60035-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2012] [Indexed: 11/16/2022]
Abstract
AIM Combine disproportionality analysis with dynamically interactive graphics to understand spontaneously-reported adverse events in pharmacovigilance. METHODS Four statistical methods, including Reporting Odds Ratio, Proportional Reporting Ratio, Multi-Item Gamma Poisson Shrinker and Bayesian Confidence Propagation Neural Network that are used for computing disproportionality are described. Tree maps and other graphical techniques are used to display the disproportionality results. RESULTS Spontaneously-reported adverse events in pharmacovigilance are collected from physicians, patients, or the medical literature by regulatory agencies, pharmaceutical companies and device manufacturers to monitor the safety of a product once it reaches the market. In order to identify potential safety-signals, disproportionality analysis methods compare the rate at which a particular event of interest co-occurs with a given drug with the rate this event occurs without the drug in the event database. Tree maps are employed to interactively display the adverse events for particular drugs and compare the adverse events among the drugs. CONCLUSION Interactive graphical displays of disproportionality allow the analyst to quickly identify safety signals and perform additional follow-up analyses. Combining statistical methods with dynamically interactive graphics affords insights into the data inaccessible by traditional analysis methods.
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Qaqish BF, Zink RC, Preisser JS. Orthogonalized residuals for estimation of marginally specified association parameters in multivariate binary data. Scand Stat Theory Appl 2012; 39:515-527. [PMID: 23180903 PMCID: PMC3501755 DOI: 10.1111/j.1467-9469.2012.00802.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This paper focuses on marginal regression models for correlated binary responses when estimation of the association structure is of primary interest. A new estimating function approach based on orthogonalized residuals is proposed. A special case of the proposed procedure allows a new representation of the alternating logistic regressions method through marginal residuals. The connections between second-order generalized estimating equations, alternating logistic regressions, pseudo-likelihood and other methods are explored. Eficiency comparisons are presented, with emphasis on variable cluster size and on the role of higher-order assumptions. The new method is illustrated with an analysis of data on impaired pulmonary function.
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Affiliation(s)
- Bahjat F Qaqish
- Department of Biostatistics, University of North Carolina at Chapel Hill
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Stewart WC, Crean CS, Zink RC, Brubaker K, Haque RM, Hwang DG. Pharmacokinetics of azithromycin and moxifloxacin in human conjunctiva and aqueous humor during and after the approved dosing regimens. Am J Ophthalmol 2010; 150:744-751.e2. [PMID: 20813346 DOI: 10.1016/j.ajo.2010.05.039] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2010] [Revised: 05/27/2010] [Accepted: 05/30/2010] [Indexed: 11/30/2022]
Abstract
PURPOSE To evaluate the ocular pharmacokinetics of azithromycin and moxifloxacin in human conjunctiva and aqueous humor in subjects undergoing cataract surgery. DESIGN Multicenter, open-label, randomized study. METHODS Subjects scheduled for routine cataract surgery and with normal-appearing conjunctiva were eligible. One conjunctival biopsy sample and 1 aqueous humor sample were obtained from subjects randomly assigned to 1 of 10 prespecified time points (1 to 312 hours) after treatment initiation of azithromycin ophthalmic solution 1% or moxifloxacin ophthalmic solution 0.5%. Samples were assayed using liquid chromatography tandem mass spectrometry. RESULTS Azithromycin 1% provided high concentrations (peak level, 559.7 μg/g) in human conjunctiva that were sustained at levels 1 to 2 orders of magnitude higher than those of moxifloxacin 0.5% throughout the 7-day dosing period and for at least 7 days thereafter. Azithromycin also showed an extended half-life (65.7 hours) in conjunctiva relative to that of moxifloxacin (28.6 hours). Accordingly, the concentration of azithromycin was maintained well above the minimum inhibitory concentration required for inhibition of growth of 90% of tested bacterial isolates for at least 7 days, whereas moxifloxacin conjunctival levels fell to levels at or less than the minimum inhibitory concentration required for inhibition of growth of 90% of tested bacterial isolates approximately 24 hours after the last dose. Peak aqueous humor concentration of moxifloxacin was higher (0.77 μg/mL) than that of azithromycin (0.053 μg/mL). No clinically relevant safety findings were observed. CONCLUSIONS Azithromycin 1% demonstrated high, therapeutic levels in the conjunctiva that were maintained up to 7 days after completion of a 1-week dosing regimen. Aqueous humor levels, however, were subtherapeutic with this dosing regimen. In comparison, moxifloxacin achieved lower conjunctival tissue levels, but higher aqueous humor levels.
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Affiliation(s)
- William C Stewart
- PRN Pharmaceutical Research Network, LLC, Charleston, South Carolina, USA
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Lai CL, Shouval D, Lok AS, Chang TT, Cheinquer H, Goodman Z, DeHertogh D, Wilber R, Zink RC, Cross A, Colonno R, Fernandes L. Entecavir versus lamivudine for patients with HBeAg-negative chronic hepatitis B. N Engl J Med 2006; 354:1011-20. [PMID: 16525138 DOI: 10.1056/nejmoa051287] [Citation(s) in RCA: 865] [Impact Index Per Article: 48.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Entecavir is a potent and selective antiviral agent that has demonstrated efficacy in phase 2 studies in patients with hepatitis B e antigen (HBeAg)-negative chronic hepatitis B. METHODS In this phase 3, double-blind trial, we randomly assigned 648 patients with HBeAg-negative chronic hepatitis B who had not previously been treated with a nucleoside analogue to receive 0.5 mg of entecavir or 100 mg of lamivudine once daily for a minimum of 52 weeks. The primary efficacy end point was histologic improvement (a decrease by at least two points in the Knodell necroinflammatory score, without worsening of fibrosis). RESULTS Histologic improvement after 48 weeks of treatment occurred in 208 of 296 patients in the entecavir group who had adequate baseline liver-biopsy specimens that could be evaluated (70 percent), as compared with 174 of 287 such patients in the lamivudine group (61 percent, P=0.01). More patients in the entecavir group than in the lamivudine group had undetectable serum hepatitis B virus (HBV) DNA levels according to a polymerase-chain-reaction assay (90 percent vs. 72 percent, P<0.001) and normalization of alanine aminotransferase levels (78 percent vs. 71 percent, P=0.045). The mean reduction in serum HBV DNA levels from baseline to week 48 was greater with entecavir than with lamivudine (5.0 vs. 4.5 log [on a base-10 scale] copies per milliliter, P<0.001). There was no evidence of resistance to entecavir. Safety and adverse-event profiles were similar in the two groups. CONCLUSIONS Among patients with HBeAg-negative chronic hepatitis B who had not previously been treated with a nucleoside analogue, the rates of histologic improvement, virologic response, and normalization of alanine aminotransferase levels were significantly higher at 48 weeks with entecavir than with lamivudine. The safety profile of the two agents was similar, and there was no evidence of viral resistance to entecavir. (ClinicalTrials.gov number, NCT00035789.).
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Sloane PD, Hoeffer B, Mitchell CM, McKenzie DA, Barrick AL, Rader J, Stewart BJ, Talerico KA, Rasin JH, Zink RC, Koch GG. Effect of Person-Centered Showering and the Towel Bath on Bathing-Associated Aggression, Agitation, and Discomfort in Nursing Home Residents with Dementia: A Randomized, Controlled Trial. J Am Geriatr Soc 2004; 52:1795-804. [PMID: 15507054 DOI: 10.1111/j.1532-5415.2004.52501.x] [Citation(s) in RCA: 198] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES To evaluate the efficacy of two nonpharmacological techniques in reducing agitation, aggression, and discomfort in nursing home residents with dementia. The techniques evaluated were person-centered showering and the towel bath (a person-centered, in-bed bag-bath with no-rinse soap). DESIGN A randomized, controlled trial, with a usual-care control group and two experimental groups, with crossover. SETTING Nine skilled nursing facilities in Oregon and six in North Carolina. PARTICIPANTS Seventy-three residents with agitation during bathing (69 completed the trial) and 37 nursing assistants who bathed them. MEASUREMENTS Agitation and aggression were measured using the Care Recipient Behavior Assessment; discomfort was measured using a modification of the Discomfort Scale for Dementia of the Alzheimer Type. Raters who were blinded to subject status coded both from videotaped baths. Secondary measures of effect included bath duration, bath completeness, skin condition, and skin microbial flora. RESULTS All measures of agitation and aggression declined significantly in both treatment groups but not in the control group, with aggressive incidents declining 53% in the person-centered shower group (P<.001) and 60% in the towel-bath group (P<.001). Discomfort scores also declined significantly in both intervention groups (P<.001) but not in the control group. The two interventions did not differ in agitation/aggression reduction, but discomfort was less with the towel bath (P=.003). Average bath duration increased significantly (by a mean of 3.3 minutes) with person-centered showering but not with the towel bath. Neither intervention resulted in fewer body parts being bathed; both improved skin condition; and neither increased colonization with potentially pathogenic bacteria, corynebacteria, or Candida albicans. CONCLUSION Person-centered showering and the towel bath constitute safe, effective methods of reducing agitation, aggression, and discomfort during bathing of persons with dementia.
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Affiliation(s)
- Philip D Sloane
- Department of Family Medicine, Cecil G.Sheps Center for Health Services Research, University of North Carolina, Chapel Hill, NC 27499, USA.
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Rywik TM, Blackman MR, Yataco AR, Vaitkevicius PV, Zink RC, Cottrell EH, Wright JG, Katzel LI, Fleg JL. Enhanced endothelial vasoreactivity in endurance-trained older men. J Appl Physiol (1985) 1999; 87:2136-42. [PMID: 10601160 DOI: 10.1152/jappl.1999.87.6.2136] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Using external vascular ultrasound, we measured brachial artery diameter (Diam) at rest, after release of 4 min of limb ischemia, i. e., endothelium-dependent dilation (EDD), and after sublingual nitroglycerin, i.e., non-endothelium-dependent dilation (NonEDD), in 35 healthy men aged 61-83 yr: 12 endurance athletes (A) and 23 controls (C). As anticipated, treadmill exercise maximal oxygen consumption (VO(2 max)) was significantly higher in A than in C (40. 2 +/- 6.6 vs. 27.9 +/- 3.8 ml. kg(-1). min(-1); respectively, P < 0. 0001). With regard to arterial physiology, A had greater EDD (8.9 +/- 4.2 vs. 5.7 +/- 3.5%; P = 0.02) and a tendency for higher NonEDD (13.9 +/- 6.7 vs. 9.7 +/- 4.2%; P = 0.07) compared with C. By multiple linear regression analysis in the combined sample of older men, only baseline Diam (beta = -2.0, where beta is the regression coefficient; P = 0.005) and VO(2 max) (beta = 0.23; P = 0.003) were independent predictors of EDD; similarly, only Diam (beta = -4.0; P = 0.003) and VO(2 max) (beta = 0.27; P = 0.01) predicted NonEDD. Thus endurance-trained older men demonstrate both augmented EDD and NonEDD, consistent with a generalized enhanced vasodilator responsiveness, compared with their sedentary age peers.
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Affiliation(s)
- T M Rywik
- Laboratory of Cardiovascular Science, Gerontology Research Center, National Institute on Aging, Baltimore, Maryland 21224, USA
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Rywik TM, Zink RC, Gittings NS, Khan AA, Wright JG, O'Connor FC, Fleg JL. Independent prognostic significance of ischemic ST-segment response limited to recovery from treadmill exercise in asymptomatic subjects. Circulation 1998; 97:2117-22. [PMID: 9626171 DOI: 10.1161/01.cir.97.21.2117] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Although exercise-induced ST depression is an independent predictor of future coronary events in asymptomatic populations, the predictive value of ST depression beginning after exercise cessation is unknown. METHODS AND RESULTS We analyzed the treadmill exercise tests of 825 healthy volunteers who were 22 to 89 years of age from the Baltimore Longitudinal Study of Aging. All subjects were free from coronary heart disease by history, physical examination, and resting ECG. From 825 participants, 611 (group 0) had no ischemic ST-segment changes during or after treadmill exercise, while 214 subjects developed > or = 1-mm flat or downsloping ST depression: 151 (group 1) had ST changes starting during exercise, and 63 (group 2) had changes limited to recovery. Groups 1 and 2 were similar in age, sex, smoking status, hypertension prevalence, fasting plasma glucose, and serum cholesterol (CHOL). However, both groups were older and had higher CHOL and prevalence of hypertension than group 0. Treadmill exercise duration, peak oxygen consumption, and maximal heart rate were similar between groups 1 and 2 but were lower than in group 0 (each P < 0.05). During a mean follow-up time of 9 years, 55 subjects developed coronary events (angina pectoris, myocardial infarction, or coronary death): 21 of 611 (3.4%) in group 0, 22 of 151 (14.6%) in group 1, and 12 of 63 (19%) in group 2 (P = 0.001). By survival analysis, the risk of coronary events was similar in groups 1 and 2 but significantly higher than in group 0 (P < 0.0001). Multiple logistic regression showed that age (odds ratio [OR] = 1.07 per year, P = 0.00001), CHOL (OR = 1.02 per 1 mg, P = 0.0001), and presence of ST-segment depression (OR = 2.59, P = 0.007 and OR = 2.38, P = 0.04 for groups 1 and 2, respectively) were independent predictors of events. CONCLUSIONS Thus, ischemic ST-segment changes developing during recovery from treadmill exercise in apparently healthy individuals have adverse prognostic significance similar to those appearing during exercise.
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Affiliation(s)
- T M Rywik
- Laboratory of Cardiovascular Science, Gerontology Research Center, National Institute on Aging, Baltimore, Md. 21224, USA
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