The Prevention and Treatment of Missing Data in Clinical Trials
The Prevention and Treatment of Missing Data in Clinical Trials

Author: National Research Council

Publisher: National Academies Press

Published: 2010-12-21

Total Pages: 163

ISBN-13: 030918651X

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Randomized clinical trials are the primary tool for evaluating new medical interventions. Randomization provides for a fair comparison between treatment and control groups, balancing out, on average, distributions of known and unknown factors among the participants. Unfortunately, these studies often lack a substantial percentage of data. This missing data reduces the benefit provided by the randomization and introduces potential biases in the comparison of the treatment groups. Missing data can arise for a variety of reasons, including the inability or unwillingness of participants to meet appointments for evaluation. And in some studies, some or all of data collection ceases when participants discontinue study treatment. Existing guidelines for the design and conduct of clinical trials, and the analysis of the resulting data, provide only limited advice on how to handle missing data. Thus, approaches to the analysis of data with an appreciable amount of missing values tend to be ad hoc and variable. The Prevention and Treatment of Missing Data in Clinical Trials concludes that a more principled approach to design and analysis in the presence of missing data is both needed and possible. Such an approach needs to focus on two critical elements: (1) careful design and conduct to limit the amount and impact of missing data and (2) analysis that makes full use of information on all randomized participants and is based on careful attention to the assumptions about the nature of the missing data underlying estimates of treatment effects. In addition to the highest priority recommendations, the book offers more detailed recommendations on the conduct of clinical trials and techniques for analysis of trial data.

Risk-Based Waste Classification in California
Risk-Based Waste Classification in California

Author: National Research Council

Publisher: National Academies Press

Published: 1999-08-14

Total Pages: 235

ISBN-13: 0309065445

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The Department of Toxic Substances Control (DTSC) of the State of California Environmental Protection Agency is in the process of complying with the Regulatory Structure Update. The Regulatory Structure Update is a comprehensive review and refocusing of California's system for identifying and regulating management of hazardous wastes. As part of this effort, the DTSC proposes to change its current waste classification system that categorizes wastes as hazardous or nonhazardous based on their toxicity. Under the proposed system there would be two risk-based thresholds rather than the single toxicity threshold currently used to distinguish between the wastes. Wastes that contain specific chemicals at concentrations that exceed the upper threshold will be designated as hazardous; those below the lower threshold will be nonhazardous; and those with chemical concentrations between the two thresholds will be "special" wastes and subject to variances for management and disposal. The proposed DTSC system combines toxicity information with short or long-term exposure information to determine the risks associated with the chemicals. Under section 57004 of the California Health and Safety Code, the scientific basis of the proposed waste classification system is subject to external scientific peer review by the National Academy of Sciences, the University of California, or other similar institution of higher learning or group of scientists. This report addresses that regulatory requirement.

Sharing Clinical Trial Data
Sharing Clinical Trial Data

Author: Institute of Medicine

Publisher: National Academies Press

Published: 2015-04-20

Total Pages: 236

ISBN-13: 0309316324

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Data sharing can accelerate new discoveries by avoiding duplicative trials, stimulating new ideas for research, and enabling the maximal scientific knowledge and benefits to be gained from the efforts of clinical trial participants and investigators. At the same time, sharing clinical trial data presents risks, burdens, and challenges. These include the need to protect the privacy and honor the consent of clinical trial participants; safeguard the legitimate economic interests of sponsors; and guard against invalid secondary analyses, which could undermine trust in clinical trials or otherwise harm public health. Sharing Clinical Trial Data presents activities and strategies for the responsible sharing of clinical trial data. With the goal of increasing scientific knowledge to lead to better therapies for patients, this book identifies guiding principles and makes recommendations to maximize the benefits and minimize risks. This report offers guidance on the types of clinical trial data available at different points in the process, the points in the process at which each type of data should be shared, methods for sharing data, what groups should have access to data, and future knowledge and infrastructure needs. Responsible sharing of clinical trial data will allow other investigators to replicate published findings and carry out additional analyses, strengthen the evidence base for regulatory and clinical decisions, and increase the scientific knowledge gained from investments by the funders of clinical trials. The recommendations of Sharing Clinical Trial Data will be useful both now and well into the future as improved sharing of data leads to a stronger evidence base for treatment. This book will be of interest to stakeholders across the spectrum of research-from funders, to researchers, to journals, to physicians, and ultimately, to patients.

Knowing What Works in Health Care
Knowing What Works in Health Care

Author: Institute of Medicine

Publisher: National Academies Press

Published: 2008-05-29

Total Pages: 279

ISBN-13: 0309113563

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There is currently heightened interest in optimizing health care through the generation of new knowledge on the effectiveness of health care services. The United States must substantially strengthen its capacity for assessing evidence on what is known and not known about "what works" in health care. Even the most sophisticated clinicians and consumers struggle to learn which care is appropriate and under what circumstances. Knowing What Works in Health Care looks at the three fundamental health care issues in the United States-setting priorities for evidence assessment, assessing evidence (systematic review), and developing evidence-based clinical practice guidelines-and how each of these contributes to the end goal of effective, practical health care systems. This book provides an overall vision and roadmap for improving how the nation uses scientific evidence to identify the most effective clinical services. Knowing What Works in Health Care gives private and public sector firms, consumers, health care professionals, benefit administrators, and others the authoritative, independent information required for making essential informed health care decisions.

Scientific and Technical Aerospace Reports
Scientific and Technical Aerospace Reports

Author:

Publisher:

Published:

Total Pages: 632

ISBN-13:

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Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.