Methods Seminar- Heather J. Gunn, PhD on A Gentle Introduction to Factor Analysis and Measurement Invariance

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Heather J. Gunn, PhD
Postdoctoral Scholar at UCLA
Global Center for Children and Families
Tuesday, December 10, 2pm-3pm

There are outcomes of interest, like math ability or anxiety, which cannot be directly measured. One way to indirectly measure these outcomes is to measure a set of variables that are related to the construct of interest (e.g., item responses). For instance, we often measure depression by administering the Patient Health Questionnaire, a set of 9 questions that measures the presence and severity of depression. Theoretically, we believe there is an underlying construct, called a latent variable, which directly influences the observed variables. If group comparisons on the latent variable are of interest, such as comparing males and females on depression, then the relationship between the latent variable and the probability of obtaining a particular score on the observed variables needs to be equal across groups. A measure is invariant if the groups have the same probability. If the groups do not have the same probability of obtaining a particular score on the observed variables, then the measure is non-invariant and the meaning and metric of the latent variable differs by group, making valid group comparisons impossible.

This presentation gave a brief overview of factor analysis and how measurement invariance is tested in the factor analytic framework.

The CHIPTS’ Methods Core hosts a monthly seminar series, which are one-hour workshops on research and statistical methods.  The seminars are open to HIV researchers, faculty, students, and community. To see previous seminars, check out the Methods Seminar tag or you can find seminar videos on our Youtube Channel! This series is hosted by the Center for HIV Identification, Prevention, and Treatment Services (CHIPTS) and made possible by funds from the National Institute of Mental Health (MH058107).

Methods Seminar- Karen L. Fortuna, PhD on Co-Designing Mental Health Smartphone Apps with People with Serious Mental Illness to Impact Population Health

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Karen L. Fortuna, PhD, MSW
Assistant Professor of Psychiatry
Geisel School of Medicine
Dartmouth College

Friday, October 25, 10:00am-11:00am

The proliferation of digital mental health has the potential to redesign clinical and research practices. Digital mental health will continue to grow rapidly and could have a large impact on population health. However, despite millions of dollars to develop digital mental health interventions and evidence for their efficacy and effectiveness, intervention uptake in real-world settings is limited. On average, it takes 17 years for research findings to be implemented into practice. Not surprisingly, estimates suggest that between 90-75% of all individuals are not receiving care supported by a scientific evidence base. The lack of uptake can be explained by the difficulties associated with translating research into practice in combination with the absence of consideration to scalability during early intervention research development phases. Traditionally, early intervention research development phases have remained separate from scalability considerations embedded within the implementation research phases, and even require different expertise; however, there is a burgeoning consensus that scalability consideration should be included during early research development phases.

This presentation discussed the advancing role of peer support specialists (i.e., people with a lived experience of a mental health condition) in co-designing in digital mental health interventions with a focus on implementation and potential mechanisms that act as barriers and facilitators to scaling up digital mental health intervention—including (1) ethical considerations in technology development and service users’ acceptability of digital products and (2) the advancement of user-centered design to include community-engaged research with vulnerable populations.

The CHIPTS’ Methods Core hosts a monthly seminar series, which are one-hour workshops on research and statistical methods.  The seminars are open to HIV researchers, faculty, students, and community. To see previous seminars, check out the Methods Seminar tag or you can find seminar videos on our Youtube Channel! This series is hosted by the Center for HIV Identification, Prevention, and Treatment Services (CHIPTS) and made possible by funds from the National Institute of Mental Health (MH058107).

Methods Seminar- Alex Dubov, PhD on Machine Learning in Public Health Research: A Practical Introduction

Alex Dubov, PhD
Assistant Professor
Loma Linda University, Bioethics and Public Health
CHIPTS Combination Prevention Core Scientist
Tuesday, October 8th, 2pm-3pm

Artificial Intelligence is being called the new electricity—a technological invention that promises to transform our lives and the world. The resurgence of investment and enthusiasm for artificial intelligence, or the ability of machines to carry out “smart” tasks, is driven largely by advancements in the subfield of machine learning. Machine learning algorithms can analyze large volumes of complex data to find patterns and make predictions, often exceeding the accuracy and efficiency of people who are attempting the same task. Driven by tremendous growth in data collection and availability as well as computing power and accessibility, artificial intelligence and machine learning applications are rapidly growing in public health.

This presentation reviewed emerging application and implications of machine learning in public health research. The aim of this seminar was to increase participants’ understanding of machine learning, its relevance to public health research and practical challenges to its application, so as to enable participants to work in conjunction with people with technical skills in machine learning. We outlined what can and cannot be solved with machine learning models and provide a basic overview of machine learning techniques and their use.

The CHIPTS’ Methods Core hosts a monthly seminar series, which are one-hour workshops on research and statistical methods.  The seminars are open to HIV researchers, faculty, students, and community. To see previous seminars, check out the Methods Seminar tag or you can find seminar videos on our Youtube Channel! This series is hosted by the Center for HIV Identification, Prevention, and Treatment Services (CHIPTS) and made possible by funds from the National Institute of Mental Health (MH058107).

Methods Seminar- Lindsay Young, PhD on Networks and Artificial Intelligence: Computational Partners in the Study of HIV Prevention and Risk Online

The CHIPTS’ Methods Core hosts a monthly seminar series, which are one-hour workshops on research and statistical methods.  The seminars are open to HIV researchers, faculty, students, and community. To see previous seminars, check out the Methods Seminar tag or you can find seminar videos on our Youtube Channel! This series is hosted by the Center for HIV Identification, Prevention, and Treatment Services (CHIPTS) and made possible by funds from the National Institute of Mental Health (MH058107).

Methods Seminar- Sean Young, PhD, MS on Reading Between the Tweets: Using Social Media and mHealth to Change and Predict Health Behavior

The CHIPTS’ Methods Core hosts a monthly seminar series, which are one-hour workshops on research and statistical methods.  The seminars are open to HIV researchers, faculty, students, and community. To see previous seminars, check out the Methods Seminar tag or you can find seminar videos on our Youtube Channel! This series is hosted by the Center for HIV Identification, Prevention, and Treatment Services (CHIPTS) and made possible by funds from the National Institute of Mental Health (MH058107).

Methods Seminar – Michael Shin, PhD on Mapping Health

Michael Shin, PhD
Associate Professor, UCLA Department of Geography,
Geospatial @ UCLA

Tuesday, April 10, 2pm – 3pm

Center for Community Health, UCLA Wilshire Center
10920 Wilshire Blvd., Suite 350, Room 350-46 (Conference Room)

Health happens. What’s more is that health happens somewhere. Our understanding of how geography can define, shape, influence and inform health outcomes, policies, and interventions remains largely underdeveloped. This seminar provides an overview of how geospatial concepts, methods and approaches can complement and extend our understanding of health. Three brief analytical vignettes are presented to encourage and to stimulate further discussion on the potential of incorporating geospatial approaches into healthcare research, policies and interventions. First, variations in Medicare spending are situated and explored within a geographic framework. Second, the association between obesity and voting, and their respective and coincident geographies, are reviewed. Finally, results from a field experiment designed to increase civic engagement across Los Angeles are discussed in relation to making Angelenos healthier.

The CHIPTS’ Methods Core hosts a monthly seminar series, which are one-hour workshops on research and statistical methods.  The seminars are open to HIV researchers, faculty, students, and community. To see previous seminars, check out the Methods Seminar tag or you can find seminar videos on our Youtube Channel! This series is hosted by the Center for HIV Identification, Prevention, and Treatment Services (CHIPTS) and made possible by funds from the National Institute of Mental Health (MH058107).

Methods Seminar – Chunqing Lin, PhD on Dissemination and Implementation of Evidence-based Interventions: Multidisciplinary Approaches

Chunqing Lin, Ph.D.
Assistant Professor-in-Residence,
Semel Institute for Neuroscience and Human Behavior, UCLA
CHIPTS Methods Core Scientist
Tuesday, June 13, 2pm – 3pm

Interventions that have demonstrated efficacy in randomized controlled trials have been underutilized in healthcare delivery. Dissemination and implementation research seeks to understand and promote adoption and implementation of evidence-based interventions (EBI) in real-world healthcare settings. I will present two studies to illustrate the application of multidisciplinary approaches in dissemination and implementation research. The first study used conjoint analysis, a marketing research technique, to model hospital stakeholders’ decision making in adoption of an EBI. The second study identified the implementation issues and improvement strategies in the delivery of prevention of mother-to-child transmission (PMTCT) services for migrant women in China through a process examination exercise.

The CHIPTS’ Methods Core hosts a monthly seminar series, which are one-hour workshops on research and statistical methods.  The seminars are open to HIV researchers, faculty, students, and community. To see previous seminars, check out the Methods Seminar tag or you can find seminar videos on our Youtube Channel! This series is hosted by the Center for HIV Identification, Prevention, and Treatment Services (CHIPTS) and made possible by funds from the National Institute of Mental Health (MH058107).

Methods Seminar – Priya Bhagwat, PhD on Measurement of Abdominal Fat Changes and Predictors of Excess Fat Gain in HIV-Infected Individuals Initiating Therapy

Priya Bhagwat, Ph.D.
Postdoctoral Scholar
Center for HIV Identification, Prevention, and Treatment Services (CHIPTS),
Semel Institute for Neuroscience and Human Behavior, UCLA

HIV-infected individuals beginning antiretroviral treatment are faced with several metabolic complications including central fat accumulation and severe weight increases. As the HIV-infected population is at an elevated risk for cardiovascular disease, monitoring abdominal fat changes as well as understanding predictors of fat gain are especially important. My research examines the validity of accessible measures of abdominal fat changes including waist circumference and self-reported changes, as well as risk factors of abdominal fat changes and severe weight gain after therapy initiation.

 

The CHIPTS’ Methods Core hosts a monthly seminar series, which are one-hour workshops on research and statistical methods.  The seminars are open to HIV researchers, faculty, students, and community. To see previous seminars, check out the Methods Seminar tag or you can find seminar videos on our Youtube Channel! This series is hosted by the Center for HIV Identification, Prevention, and Treatment Services (CHIPTS) and made possible by funds from the National Institute of Mental Health (MH058107).

Methods Seminar – Kodi B. Arfer, PhD on Comorbidity and Medical Costs Among Medicare Beneficiaries with HIV in California: A Case Study in Predictive Data Analysis

Kodi B. Arfer. PhD
Postdoctoral Scholar
Center for HIV Identification, Prevention, and Treatment Services, Semel Institute for Neuroscience and Human Behavior, UCLA

Data analysis typically focuses on inference about the unobservable true parameters of a postulated true data-generating model. An alternative is to focus on the model’s accuracy in predicting values on outcome variables. Predictive data analysis allows evaluating a wide variety of models in a straightforward way. It produces measures of predictive accuracy that show how practically useful a model and a set of variables are in predicting an outcome. Using Medicare claims data from HIV-positive Californians, I investigate how comorbidity information—knowing what conditions other than HIV a patient has been diagnosed with—can be used to predict medical costs. I show how difficulties in the data, from highly skewed distributions to the differences between Medicare and Medicaid, can be addressed with predictive strategies. I find that comorbidities are indeed predictively useful, especially for inpatient costs.

The CHIPTS’ Methods Core hosts a monthly seminar series, which are one-hour workshops on research and statistical methods.  The seminars are open to HIV researchers, faculty, students, and community. To see previous seminars, check out the Methods Seminar tag or you can find seminar videos on our Youtube Channel! This series is hosted by the Center for HIV Identification, Prevention, and Treatment Services (CHIPTS) and made possible by funds from the National Institute of Mental Health (MH058107).

Methods Seminar – Antonio Pedro Ramos, PhD on Measuring Inequality in Early-Life Mortality Within and Between-Groups Over Time: A Bayesian Approach with Application to India

Antonio Pedro Ramos. PhD
Postdoctoral Scholar
Department of Biostatistics,
Fielding School of Public Health, UCLA
California Center for Population Research, UCLA

Most studies on early-life mortality compare mortality rates between large groups of births, such as across countries, income groups, ethnicities, or times. These studies do not measure within-group disparities. The few studies that have looked at mortality across the entire population of births, however, have used tools from the income inequality literature. Using a large data set from India, we estimate mortality risk for over 400,000 births using a Bayesian hierarchical model. We show that while measures based on the income inequality literature, such as Gini indices, are not appropriate for mortality risk, most of the variance in mortality risk occur within-groups of births. We developed a novel approach to investigate inequality in mortality risk. Our approach uncovers several important patterns in the dynamics of inequality in infant mortality and has broader applicability to other health outcomes.

The CHIPTS’ Methods Core hosts a monthly seminar series, which are one-hour workshops on research and statistical methods.  The seminars are open to HIV researchers, faculty, students, and community. To see previous seminars, check out the Methods Seminar tag or you can find seminar videos on our Youtube Channel! This series is hosted by the Center for HIV Identification, Prevention, and Treatment Services (CHIPTS) and made possible by funds from the National Institute of Mental Health (MH058107).