A Mixed Model Approach For Intent To Treat Analysis In Longitudinal Clinical Trials With Missing Values

Missing values and dropouts are common issues in longitudinal studies in all areas of medicine and public health. Intent-to-treat (ITT) analysis has become a widely accepted method for the analysis of controlled clinical trials. In most controlled clinical trials, some patients do not complete their intended followup according to the protocol for a variety of reasons; this problem generates missing values. Missing values lead to concern and confusion in identifying the ITT population, which makes the data analysis more complex and challenging. No adequate strategy exists for ITT analyses of longitudinal controlled clinical trial data with missing values. Several ad hoc strategies for dealing with missing values for an ITT analysis are common in the practice of controlled clinical trials. We performed a detailed investigation based on simulation studies to develop recommendations for this situation. We compared sizes (type I errors) and power between some popular ad hoc approaches and the linear mixed model approach under different missing value scenarios. Our results suggest that, for studies with a high percentage of missing values, the mixed model approach without any ad hoc imputation is more powerful than other options.

Analyzing Longitudinal Clinical Trial Data: A Practical Guide provide practical and easy to implement approaches for bringing the latest theory on analysis of longitudinal clinical trial data into routine practice.?This book, with its example-oriented approach that includes numerous SAS and R code fragments, is an essential resource for statisticians and graduate students specializing in medical research. The authors provide clear descriptions of the relevant statistical theory and illustrate practical considerations for modeling longitudinal data. Topics covered include choice of endpoint and statistical test; modeling means and the correlations between repeated measurements; accounting for covariates; modeling categorical data; model verification; methods for incomplete (missing) data that includes the latest developments in sensitivity analyses, along with approaches for and issues in choosing estimands; and means for preventing missing data. Each chapter stands alone in its coverage of a topic. The concluding chapters provide detailed advice on how to integrate these independent topics into an over-arching study development process and statistical analysis plan.

Nursing and Health Interventions covers the conceptual, empirical, and practical knowledge required for engaging in intervention research. This revised edition provides step-by-step guidance on the complex process of intervention development and methods for developing, delivering, evaluating and implementing intervention, supported by a wealth of examples. The text describes each essential aspect of intervention research, from generating an intervention theory, to procedures for adopting evidence-based interventions in practice. This second edition provides up-to-date coverage of intervention research and its impact on improving standards of care. Throughout the text, readers are provided with the foundational knowledge required for generating evidence that informs treatment decisions in practice, and choosing the best approaches for designing, delivering, evaluating and implementing interventions. A valuable ‘one-stop’ resource for students, researchers, and health professionals alike, this book: Covers the importance and issues of evidence-based healthcare practice, the role of theory in research in the intervention design and evaluation, and evaluation of effectiveness and implementation of interventions in a single volume Reviews the decision-making steps and the knowledge needed to inform decisions in research and practice Discusses the limitations of evidence derived from randomized controlled trials (RCTs) Written by leading experts in the field, Nursing and Health Interventions remains an invaluable resource for nursing and healthcare students, researchers, and health practitioners wanting to understand and apply intervention to improve the quality of care.

There has been remarkable progress in understanding, preventing, detecting, diagnosing, and treating cancer, resulting in a reduction of cancer incidence and mortality in the United States. Despite this, the cancer burden varies considerably by race/ethnicity and socioeconomic status. Cancer incidence rates vary markedly between racial/ethnic groups, but even more startling are the differences in outcome across groups. Cancer Disparities: Causes and Evidence-Based Solutions helps readers understand the scope and causes of this inequity by providing a detailed analysis of the many factors that result in cancer disparities across the cancer continuum, including the role of race/ethnicity, socioeconomic status, access to and use of services, insurance status, geographic variables, and differences in treatment provided to patients. Further, it is the first book to describe evidence-based, concrete solutions that can be used to reduce or even eliminate cancer health disparities. Fifteen previously unpublished studies of interventions designed specifically to achieve health equality are described. These studies focus on contextually and culturally appropriate strategies to enhance cancer prevention, screening and early detection, treatment, symptom management, and quality of life in underserved populations.

Psychodynamic Interventions in Pregnancy and Infancy builds on Björn Salomonsson’s experiences as a psychoanalytic consultant working with parents and their babies. Emotional problems during the perinatal stages can arise and be observed and addressed by a skilled midwife, nurse or health visitor. Salomonsson has developed a method combining nurse supervision and therapeutic consultations which has lowered the thresholds for parents to come and talk with him. The brief consultations concern pregnant women, mother and baby, husband and wife, toddler and parent. The theoretical framework is psychoanalytic, but the mode of work is eclectic and adapted to the family’s situation and its members’ motivation. This book details such work, which can be applied globally; perinatal psychotherapy integrated with ordinary medical health care. It also explains how psychotherapy can be made more accessible to a larger population. Via detailed case presentations, the author takes the reader through pregnancy, childbirth and the first few years of life. He also brings in research studies emphasizing the importance of early interventions, with the aim of providing therapists with arguments for such work in everyday family health care. To further substantiate such arguments, the book ends with theoretical chapters and, finally, the author’s vision of the future of a perinatal health care that integrates medical and psychological perspectives. Psychodynamic Interventions in Pregnancy and Infancy will appeal to all psychoanalysts and psychoanalytic psychotherapists working in this area, as well as clinical psychologists, clinical social workers and medical personnel working with parents and infants.

Psychoanalytic Therapy with Infants and Parents provides a clear guide to clinical psychoanalytic work with distressed babies and unhappy parents, a numerous clinical group so often in need of urgent help. Although psychoanalytic work is primarily verbal, and infants may have limited language, this form of treatment is receiving increased attention among therapists. Björn Salomonsson explores how such work can be possible and benefit infants, how to work with the parents (especially the mother), and how major psychoanalytic concepts such as primal repression, infantile sexuality and transference can be worked with and understood in these therapies. Björn Salomonsson argues that attachment concepts, though important, cannot solely help explain everyday problems with breastfeeding, sleeping, and weaning, or more recalcitrant interaction disorders. He shows how we also need psychoanalytic concepts to better understand, not only such "baby worries", but also adult clients' non-verbal communications and interactions. Throughout, he uses extensive practice-based examples and also refers to his research which provides evidence for the effectiveness of this practice. Psychoanalytic Therapy with Infants and Parents provides a unique perspective on working psychoanalytically with parents and infants. This book will be essential reading for psychoanalysts and therapists working with children as well as adults.

This is a comprehensive major reference work for our SpringerReference program covering clinical trials. Although the core of the Work will focus on the design, analysis, and interpretation of scientific data from clinical trials, a broad spectrum of clinical trial application areas will be covered in detail. This is an important time to develop such a Work, as drug safety and efficacy emphasizes the Clinical Trials process. Because of an immense and growing international disease burden, pharmaceutical and biotechnology companies continue to develop new drugs. Clinical trials have also become extremely globalized in the past 15 years, with over 225,000 international trials ongoing at this point in time. Principles in Practice of Clinical Trials is truly an interdisciplinary that will be divided into the following areas: 1) Clinical Trials Basic Perspectives 2) Regulation and Oversight 3) Basic Trial Designs 4) Advanced Trial Designs 5) Analysis 6) Trial Publication 7) Topics Related Specific Populations and Legal Aspects of Clinical Trials The Work is designed to be comprised of 175 chapters and approximately 2500 pages. The Work will be oriented like many of our SpringerReference Handbooks, presenting detailed and comprehensive expository chapters on broad subjects. The Editors are major figures in the field of clinical trials, and both have written textbooks on the topic. There will also be a slate of 7-8 renowned associate editors that will edit individual sections of the Reference.