Publications by authors named "Fisher Z"

Objective: Alcohol use offers social benefits for young adults, but also carries risk of significant negative consequences. Better understanding of processes driving alcohol use for those who experience negative consequences can prevent these harms. These at-risk young adults likely have drinking patterns in common and patterns unique to each individual.

View Article and Find Full Text PDF

Model-Implied Instrumental Variable Two-Stage Least Squares (MIIV-2SLS) is a limited information, equation-by-equation, non-iterative estimator for latent variable models. Associated with this estimator are equation specific tests of model misspecification. One issue with equation specific tests is that they lack specificity, in that they indicate that some instruments are problematic without revealing which specific ones.

View Article and Find Full Text PDF

Background: Hepatitis B infection is a major public health concern in Vanuatu, with approximately 9% of the general population estimated to be living with chronic hepatitis B. Most new infections are due to mother-to-child transmission (MTCT). Hepatitis B vaccination is available in Vanuatu, but coverage rates for first dose within 24 h of birth and third dose are suboptimal.

View Article and Find Full Text PDF

Background: The daily dynamics among affect, physical activity, and sleep are often explored by taking a unidirectional approach. Yet, obtaining a comprehensive understanding of the reciprocal dynamics among affect and health behaviors is crucial for promoting daily well-being.

Purpose: This study examined the reciprocal associations among affect, physical activity, and sleep in daily life in a U.

View Article and Find Full Text PDF

How best to model structurally heterogeneous processes is a foundational question in the social, health and behavioral sciences. Recently, Fisher et al. introduced the multi-VAR approach for simultaneously estimating multiple-subject multivariate time series characterized by common and individualizing features using penalized estimation.

View Article and Find Full Text PDF
Article Synopsis
  • The study examines how family and peer stressors affect alcohol use patterns in Mexican-origin adolescents over time, utilizing longitudinal data from 674 participants.
  • Results indicate that early adolescent stressors are more effective as predictors of alcohol use trajectories when analyzed as growth trajectories rather than as individual instances of stress.
  • The findings highlight the importance of developing strategies to reduce the long-term impact of stressors on alcohol consumption among Latinx youth.
View Article and Find Full Text PDF

This work introduces a novel framework for dynamic factor model-based group-level analysis of multiple subjects time-series data, called GRoup Integrative DYnamic factor (GRIDY) models. The framework identifies and characterizes intersubject similarities and differences between two predetermined groups by considering a combination of group spatial information and individual temporal dynamics. Furthermore, it enables the identification of intrasubject similarities and differences over time by employing different model configurations for each subject.

View Article and Find Full Text PDF

This paper explores the relation between within-person and between-person research designs using the concept of ergodicity from statistical mechanics in physics. We demonstrate the consequences of ergodicity using several real data examples from previously published studies. We then create several simulated examples that illustrate the independence of within-person processes from between-person differences, and pair these examples with analytic results that reinforce our conclusions.

View Article and Find Full Text PDF

Acquired Brain Injury (ABI) often results in significant challenges, yet it may also facilitate Post-Traumatic Growth (PTG). This review explores a critical question: "What are the main factors contributing to PTG following ABI, and what potential barriers to its development are perceived by ABI survivors?" Here we aim to systematically uncover these contributors and barriers to PTG through a meta-synthesis, involving a comprehensive review of previously published qualitative research on this topic. A literature search was conducted across PsycINFO, CINAHL, and MEDLINE up to December 2022 to identify studies for inclusion.

View Article and Find Full Text PDF

Assistive technology has great potential to help individuals living with chronic health conditions, however devices often fail to align with the unique requirements of users. These results in device abandonment and missed opportunities to benefit people. This exploratory study aims to evaluate the short and longer-term satisfaction, psychological benefit, use and resources involved in co-designed customised assistive devices within a current healthcare service.

View Article and Find Full Text PDF
Article Synopsis
  • Contamination in child maltreatment research can undermine the validity of findings by misrepresenting the effects of maltreatment on children's behavior.
  • By employing a dual-measurement strategy, this study effectively identified and controlled for contamination, leading to more accurate causal effect size estimates related to child behavior problems.
  • Results showed that controlling for contamination significantly improved the statistical significance and size of effect estimates for internalizing behaviors, emphasizing the need for proper methods in such research.
View Article and Find Full Text PDF

Obsessive-compulsive symptoms (OCS) are relatively common during adolescence although most individuals do not meet diagnostic criteria for obsessive-compulsive disorder (OCD). Nonetheless, OCS during adolescence are associated with comorbid psychopathologies and behavioral problems. Heightened levels of environmental stress and greater functional connectivity between the somatomotor network and putamen have been previously associated with elevated OCS in OCD patients relative to healthy controls.

View Article and Find Full Text PDF

Background: Acquired brain injury (ABI) and other chronic conditions are placing unprecedented pressure on healthcare systems. In the UK, 1.3 million people live with the effects of brain injury, costing the UK economy approximately £15 billion per year.

View Article and Find Full Text PDF

Contamination is a methodological phenomenon occurring in child maltreatment research when individuals in an established comparison condition have, in reality, been exposed to maltreatment during childhood. The current paper: (1) provides a conceptual and methodological introduction to contamination in child maltreatment research, (2) reviews the empirical literature demonstrating that the presence of contamination biases causal estimates in both prospective and retrospective cohort studies of child maltreatment effects, (3) outlines a dual measurement strategy for how child maltreatment researchers can address contamination, and (4) describes modern statistical methods for generating causal estimates in child maltreatment research after contamination is controlled. Our goal is to introduce the issue of contamination to researchers examining the effects of child maltreatment in an effort to improve the precision and replication of causal estimates that ultimately inform scientific and clinical decision-making as well as public policy.

View Article and Find Full Text PDF

Rapid developments over the last several decades have brought increased focus and attention to the role of time scales and heterogeneity in the modeling of human processes. To address these emerging questions, subgrouping methods developed in the discrete-time framework-such as the vector autoregression (VAR)-have undergone widespread development to identify shared nomothetic trends from idiographic modeling results. Given the dependence of VAR-based parameters on the measurement intervals of the data, we sought to clarify the strengths and limitations of these methods in recovering subgroup dynamics under different measurement intervals.

View Article and Find Full Text PDF

Purpose: Co-design has previously been used to design custom assistive devices, involving the end user in the process to ensure the device meets their needs. From devices previously created, designs could be re-used and modified to meet variations in the needs of other individuals with similar clinical needs. This service evaluation explored the re-usability of a holder for helping administer the spray medication Sativex, for individuals with multiple sclerosis.

View Article and Find Full Text PDF

Metformin has effects beyond its antihyperglycemic properties, including altering the localization of membrane receptors in cancer cells. Metformin decreases human epidermal growth factor receptor (HER) membrane density. Depletion of cell-surface HER decreases antibody-tumor binding for imaging and therapeutic approaches.

View Article and Find Full Text PDF

The Botshelo Ba Trans study was the first HIV bio-behavioral survey conducted with transgender women in South Africa. Engaging research with marginalized communities requires clear points of entry, reference points for understanding the internal culture, and establishing trust and understanding. The community-based participatory research approach guided the development and implementation of this study.

View Article and Find Full Text PDF

Significant heterogeneity in network structures reflecting individuals' dynamic processes can exist within subgroups of people (e.g., diagnostic category, gender).

View Article and Find Full Text PDF

Although life saving, health inequities exist regarding access and patient outcomes in Coronary artery bypass grafting (CABG), especially among marginalized groups. This scoping review's goal is to outline existing literature and highlight gaps for future research. Researchers followed guidance from the Joanna Briggs Institute and PRISMA extension for scoping reviews.

View Article and Find Full Text PDF