Statistical approaches in oncology clinical development: Current paradigm and methodological advancement. Satrajit Roychoudhury and Soumi Lahiri. Boca Raton: Chapman and Hall/CRC.

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151915/1/biom13129.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151915/2/biom13129_am.pd

Sleep, Executive Control, and Psychopathology in Children: A Longitudinal Study and an Examination of Brief Sleep Treatment

Researchers have acknowledged that poor sleep is not merely a symptom of psychopathology but also a contributing factor to the development of psychopathology in children (Walker & Harvey, 2010). However, more research is needed to explicate the associations among sleep, executive control (EC), and psychopathology. Specifically, there are few studies using longitudinal designs and limited research on how treating sleep can improve mental health symptoms. This dissertation provides a conceptual framework for the associations among sleep, EC, and psychopathology. The conceptual framework is bolstered by two studies. Study 1 is an examination of early sleep problems and preschool EC as predictors of risk for attention-deficit/hyperactivity disorder (ADHD) using an extended longitudinal design within a community sample. Study 2 is a pilot of a brief sleep treatment for children presenting to an outpatient clinic for emotional and behavioral disorders. Study 1 consisted of a cohort sequential, longitudinal design (N = 271). At study entry, parents answered questions about sleep when children were three years old. Then, children completed nine behavioral EC tasks in the laboratory at 4.5 years. In the spring of 4th grade, teachers completed measures of ADHD symptoms. The results of a latent moderated structural equation (LMS) model demonstrated that early sleep problems and EC deficits predicted later ADHD symptoms. EC moderated the relationship between sleep problems and ADHD symptoms, such that children with both sleep problems and poor EC were particularly vulnerable to experiencing ADHD symptoms. Study 2 was an evaluation of a treatment protocol involving one to three sessions of sleep treatment followed by behavioral treatment of mental health symptoms. Parents of children ages six to 11 years (N = 13) completed measures of psychopathology symptoms and EC at baseline and following sleep treatment. Additionally, children wore actigraphs to objectively measure sleep, and parents completed weekly assessments of children’s symptoms. The results indicated that there was a rapid effect of sleep treatment such that psychopathology and EC improved from baseline. A full understanding of the associations among sleep, EC, and psychopathology is critical for improving existing theories and developing more effective interventions. Adviser: Timothy D. Nelso

Preschooler Attachment and Adolescent Psychological Flexibility

Psychological Flexibility is identified as a fundamental aspect of psychological health by Kashdan (2010). Broadly, it refers to being open, aware, and actively engaged (Hayes & Monestes, 2016). Increasing Psychological Flexibility is a chief aim of Acceptance and Commitment Therapy.https://scholarworks.moreheadstate.edu/celebration_posters_2023/1063/thumbnail.jp

Inference for the median residual life function in sequential multiple assignment randomized trials

In survival analysis, median residual lifetime is often used as a summary measure to assess treatment effectiveness; it is not clear, however, how such a quantity could be estimated for a given dynamic treatment regimen using data from sequential randomized clinical trials. We propose a method to estimate a dynamic treatment regimen‐specific median residual life (MERL) function from sequential multiple assignment randomized trials. We present the MERL estimator, which is based on inverse probability weighting, as well as, two variance estimates for the MERL estimator. One variance estimate follows from Lunceford, Davidian and Tsiatis' 2002 survival function‐based variance estimate and the other uses the sandwich estimator. The MERL estimator is evaluated, and its two variance estimates are compared through simulation studies, showing that the estimator and both variance estimates produce approximately unbiased results in large samples. To demonstrate our methods, the estimator has been applied to data from a sequentially randomized leukemia clinical trial. Copyright © 2013 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106925/1/sim6042.pd

Adverse Childhood Events, Safety, & Comfort: Associations with Adolescent Symptoms

A PowerPoint that accompanied a oral presentation.https://scholarworks.moreheadstate.edu/celebration_posters_2023/1065/thumbnail.jp

A Bayesian analysis of small n sequential multiple assignment randomized trials (snSMARTs)

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146269/1/sim7900.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146269/2/sim7900_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146269/3/A_Bayesian_Analysis_of_snSMART_Revision_Supplimentary.pd

Habitat use of surf scoters wintering in the mesohaline region of the mainstem Chesapeake Bay, Maryland

Surf scoters (Melanitta perspicillata) are common in coastal waters during winter, but remain one of the least studied waterfowl in North America despite indications of a declining population. Surf scoter foraging was investigated in the mesohaline region of the Chesapeake Bay during 2004-2005. The study compared biological and physical characteristics of benthic habitats among scoter feeding and non-feeding sites. Benthic samples were taken seasonally via a Peterson grab. Surf scoters foraged over oyster bar, packed clay and sand habitats, but avoided mud habitats. Clam densities varied seasonally, increasing over winter regardless of scoter foraging activity. Foraging activity appeared to influence hooked mussel densities on hard bottoms. Lack of foraging over mud habitats, where visibility can be limited, suggests that surf scoters may be visual predators and may have been impacted by habitat sedimentation The correlation of hooked mussel with oyster bars suggests that oyster restoration efforts may positively impact surf scoters

Survival Analysis of Shared-Path Adaptive Treatment Strategies

Adaptive treatment strategies closely mimic the reality of a physician's prescription process where the physician prescribes a medication to his/her patient and based on that patient's response to the medication, modifies the treatment. Two-stage randomization designs, more generally, sequential multiple assignment randomization trial (SMART) designs, are useful to assess adaptive treatment strategies where the interest is in comparing the entire sequence of treatments, including the patient's intermediate response. In this dissertation, we introduce the notion of shared-path and separate-path adaptive treatment strategies and propose weighted log-rank statistics to compare overall survival distributions of two shared-path or multiple two-stage adaptive treatment strategies. Large sample properties of the statistics are derived and the type I error rate and power of the tests are compared to standard statistics through simulation. We also propose a sample size equation to power a two-stage SMART comparing the overall survival of multiple adaptive treatment strategies. Public health significance: The treatment of many diseases and illnesses, especially those which are chronic (cancer, AIDS, depression, substance abuse, ADHD), includes sequences of treatments based on the individual's characteristics, behaviors, and responses. Treatment is inherently dynamic, but often, clinical trials are not designed or analyzed to take this dynamic feature into account. We present methods to adequately power and analyze clinical trials with time-to-event data which aim to compare these individualized sequences of treatments or adaptive treatment strategies. Through these methods and by comparing adaptive treatment strategies, patient outcomes can be operationalized and improved over time