Principal Investigators’ New Websites

May 6, 2020:

Stephanie Lanza, Bethany Bray, Linda Collins, Susan Murphy, Runze LiAs previously announced, substantial changes lie ahead for The Methodology Center. Over the coming months, we will stop updating this website. Resources will remain available for at least a year, but in order to provide the latest information, each of our investigators will maintain her or his own website. These sites will include content developed at The Methodology Center and new resources related to the researcher’s future work.

Stephanie Lanza and Ashley Linden-Carmichael built a website for the Addictions and Innovative Methods (AIM) lab. Their great new site,, describes their research and includes the content about time-varying effect modeling (TVEM) from The Methodology Center’s website.

Susan Murphy has incorporated The Methodology Center’s content on just-in-time adaptive interventions in her website, The site also includes workshop materials and other resources.

Bethany Bray‘s new site at will include The Methodology Center’s resources for latent class analysis (LCA) and latent transition analysis (LTA). Bethany has concrete plans for new LCA and LTA resources, so stay tuned.

Runze Li will update his page at to incorporate Methodology Center resources on variable screening and variable selection for high-dimensional data analysis.

Linda Collins will build a new website to house The Methodology Center’s content on the multiphase optimization strategy (MOST) for optimizing interventions after she moves to New York University. In the meantime, follow Linda on Twitter, @collins_most.

Daniel Almirall and Inbal “Billie” Nahum-Shani’s informative website,, will soon incorporate The Methodology Center’s resources for the sequential, multiple assignment, randomized trial (SMART).

More information will follow in June or July. Thank you for staying connected to our research! We are all proud of our time at The Methodology Center and very excited about the future.

Time-Varying Effect Modeling Interest Group for Penn State

Ashley Linden-CarmichaelAugust 5, 2019:

This fall, Methodology Center Investigator Ashley Linden-Carmichael will be hosting a special interest group for researchers who are interested in time-varying effect modeling (TVEM). TVEM is a data-analysis method that extends linear regression to allow the association between two variables to be modeled without making assumptions about the nature of the association.

The group will provide a forum for researchers to discuss their own research and to learn from others. Students, post-doctoral researchers and faculty are all invited.

Want to learn more about TVEM before the first meeting? Use the TVEM Learning Path to learn what questions TVEM can answer, how to prepare your data, how to run the macro, and more.

TVEM Special Interest Group
Dates: Tuesdays 9/24, 10/22, 11/19, and 12/10
noon – 1 p.m.
401 Health and Human Development Building
Contact: Ashley Linden-Carmichael (

To learn more, look for details about the TVEM course that Ashley will teach in spring semester of 2020.

New Resource for Learning TVEM

simulated TVEM graphicMay 10, 2019:

Our newest resource helps scientists teach themselves how to use our time-varying effect modeling (TVEM) SAS macro. TVEM allows scientists to understand how associations between variables change over time. The TVEM Learning Path is designed to allow SAS users to efficiently teach themselves how to prepare data for, plan, and run a TVEM.

The Learning Path allows users to select from a variety of educational resources including videos, presentation slides, webpages, and hands-on SAS exercises. This format allows users to access the specific content they need in the format they desire to develop their skills as quickly as possible. Content is divided into

  • Conceptual introduction,
  • Detailed introduction,
  • Running a SAS macro,
  • Flipping data from long format to wide format,
  • Preparing to run a TVEM,
  • Running a TVEM,
  • Plotting results, and
  • Running the Weighted TVEM SAS macro.

We hope the Learning Path is useful and can be applied to other methods. Please send any thoughts, suggestions, or questions about the Learning Path to

Open the TVEM Learning Path.

Join Us at SPR!

April 30, 2019:

Join us at the Society for Prevention Research (SPR) 2019 Annual Meeting, May 28 through 31 in San Francisco. Methodology Center researchers will present symposia, talks, posters, a technical demonstration, and participate in the SPR Cup. We hope to see you there! Below is a list of the places where you can find us.

Tuesday, May 28

5:30 – 7:00 p.m. Poster Session I

  • “Heavy drinking and academics: Daily-level associations, or do less serious students just drink more?” Hannah Allen
  • “Profiles of dysregulation moderate the impact of preschool teacher-student relationships on later school functioning” Benjamin Bayly
  • “Identifying substance use disorders among individuals with spinal cord injury: Using big data Sources via electronic health records” Scott Graupensperger
  • “Effects of a mindfulness training intervention on alcohol use in public school teachers” Natalia Van Doren

Wednesday, May 29

1:15 – 2:45 p.m. Roundtable: Enhancing the reach and impact of drug abuse and behavioral health preventive interventions: Mining existing data for bold new discoveries Stephanie Lanza, Discussant

5:45 – 7:00 p.m. Poster Session II

  • “Approaches to characterizing drinking episodes in college students from wearable alcohol sensors” John Felt
  • “Gender differences in the time-varying association between cigarette use and weight concerns across adolescence” Anna Hochgraf
  • “Drug use patterns among young men of color who have sex with men” Eric Layland

7:00 –8:30 MOST-ly Mingling Join Kate Guastaferro in the Eclipse Kitchen & Bar, located in the lobby of the Hyatt Regency San Francisco, to socialize and discuss issues related to the optimization of interventions.

Thursday, May 30

10:15 – 11:45 a.m. Organized Paper Symposium: Opioid and other nonmedical prescription drug use in the United States: Contemporary trends in use, co-use, and correlates to identify opportunities for prevention Stephanie Lanza, organizer

  • “Contemporary trends in nonmedical prescription drug use as a function of individual and sociodemographic characteristics: Ages 12 to 90” Stephanie Lanza
  • “Age-varying trends in co-use of marijuana and heavy episodic drinking: Implications for nonmedical prescription drug use” Ashley Linden-Carmichael

10:15 – 11:45 a.m. Sloboda and Bukoski Cup Team:  Hannah Allen, Andrew Dismukes, John Felt, Natalia Van Doren, and Adrienne Woods

10:15 – 11:45 a.m. Roundtable Discussion: SPR task force on reducing health disparities and improving equity through prevention Bethany Bray, Discussant

3:00 – 4:30 p.m. Individual paper presentations: Prevention related to drug abuse across developmental stage Bethany Bray, Moderator

3:00 – 4:30 p.m. Individual paper presentations:Family, individual, and neighborhood risk factors as predictors of long-term behavior and mental health problems 

  • “Constellations of family risk and long-term adolescent antisocial behavior: A latent profile analysis” Emily LoBracio

6:40 – 7:55 p.m. Poster Session III

  • Technology Demonstration: Software, instructional materials, videos, and other resources from The Methodology Center at Penn State Bethany Bray

Friday May 31

8:30 – 10:00 a.m. Organized Paper Symposium: Applying latent class models in prevention science: Practical solutions to everyday problems Bethany Bray, Organizer

  • “Multiple imputation of missing covariate information in latent class analysis: evaluation of a step-by-step approach” John Dziak
  • “Multilevel latent profile analysis for daily diary data: Understanding triadic family dynamics” Mengya Xia
  • “Combining latent class analysis and time-varying effect modeling: Understanding the epidemiology of alcohol use” Bethany Bray

8:30 – 10:00 a.m. Individual Paper Presentations: using mobile health techniques to understand and prevent substance use

  • “Day and within-day trends of drug cravings: Ecological momentary assessment among a sample of patients with prescription opiate dependence” Jamie Gajos

10:15 – 11:45 a.m. Plenary Session III, Mobile health (mHealth) in prevention science: Assessment, intervention, and analysis Stephanie Lanza, Chair

1:00 – 2:30 p.m. Plenary Session III Roundtable: Mobile health (mHealth) in prevention science: Assessment, intervention, and analysis Stephanie Lanza, Chair

2:45 – 4:15 p.m. Organized Paper Symposium: Using time-varying effect models to understand predictors of substance use and depression within-days and across developmental periods Benjamin Bayly, Organizer

  • “Age-varying association between childhood maltreatment and depression and substance use” Yuen Wai Hung
  • “Age-varying effects of parental warmth and closeness on adolescent and young adult substance use and depression” Benjamin Bayly

Understanding Health Disparities Among Sexual Minorities

March 27, 2019:

Cara RiceStephanie LanzaSexual minorities—people who report sexual attraction to or behavior with members of the same sex and people who identify as gay, lesbian, or bisexual—are at a higher risk for a broad range of health problems at different points in their lives. Previous research has shown that sexual minorities are more likely to experience health problems like substance-use disorders and mood or anxiety disorders. In a recent article in Annals of Epidemiology by Methodology Center Investigators Cara Exten Rice and Stephanie Lanza, the authors used time-varying effect modeling (TVEM) to examine whether the occurrence of problems changed as people aged. The authors found that the odds for anxiety and depression among sexual minorities was highest in their early 20s, while odds for poor cardiovascular health were higher in their 40s and 50s.

When asked about the reason for these disparities, Cara emphasized that this was not a causal study but indicated that disparities may result from increased stress due to discrimination and prejudice. “It’s generally believed that sexual minorities experience increased levels of stress throughout their lives as a result of discrimination, microaggressions, stigma, and prejudicial policies,” she said. “Those increased stress levels may then result in poor health in a variety of outcomes, including health behaviors like substance use and chronic diseases like heart disease .”

Stephanie said the results help shed light on understudied health risks. “Discussions about health disparities often focus on the differences between men and women, across racial and ethnic groups, or between people of different socioeconomic backgrounds. However, sexual minority groups suffer substantially disproportionate health burdens across a range of outcomes, including poor mental health and problematic substance-use behaviors.”

For the study, the researchers used data from about 30,999 participants between the ages of 18 and 65 from the National Epidemiologic Survey of Alcohol and Related Conditions-III. Data included information about past-year alcohol, tobacco and drug use disorders, as well whether the participants had a past-year history of depression, anxiety, sexually transmitted infections (STIs) or cardiovascular disease.

“We observed that odds of substance-use disorders remained constant across age for sexual minorities, while in the general population they tend to be concentrated in certain age groups,” Cara said. “We saw that sexual minorities were more likely to have these substance-use disorders even in their 40s and 50s when we see in the general population that drug use and alcohol use start to taper off.”

Cara said the findings could be used to develop programs to help prevent these health problems before they start. “A necessary first step was to understand how health disparities affecting sexual minorities vary across age,” Rice said. “These findings shed light on periods of adulthood during which intervention programs may have the largest public health impact. Additionally, future studies that examine possible drivers of these age-varying disparities, such as daily experiences of discrimination, will inform the development of intervention content to promote health equity.”

Sara A. Vasilenko, Syracuse University, and Jessica N. Fish, University of Maryland, also contributed to this research.

Featured Article: Counting Drinks to Understand Alcohol Use Disorder

November 27, 2018:
ALC - square

Alcohol use disorder (AUD) occurs more frequently among young adults than other age groups. Heavy drinking, which is a strong predictor of whether someone will experience an AUD, is common among young adults. The generally accepted guideline for “heavy episodic drinking” or a “binge” is four (for women) or five (for men) or more drinks during a drinking occasion or within a two-hour period. In a forthcoming article by Methodology Center researchers Ashley Linden-Carmichael, Michael Russell, and Stephanie Lanza, the authors used time-varying effect modeling (TVEM) to examine whether these drink thresholds provide the best picture of who is at risk for AUD.

The authors analyzed a sample of more than 6,000 young adult drinkers from the National Epidemiologic Survey on Alcohol and Related Conditions-III. Among other questions, the authors examined whether consuming different average numbers of drinks on each drinking occasion was associated with higher prevalence of AUD. They found that rates of AUD for women increased until women reached about nine drinks per drinking session, when AUD rates plateaued at about 80%. AUD rates plateaued at 80% for men when they consumed about 12 drinks. This study suggests that defining a binge as four or five drinks and focusing prevention messages around that threshold neither matches young adult behavior nor does it enable us to understand the full scope of risky drinking.

Lead author Ashley Linden-Carmichael spoke about the implications of the findings and what further questions remain. “Alcohol clinical trials often use percentage of no-binge-drinking days as a marker of the trial’s efficacy. Our results suggest that focusing on reducing the number of drinks rather than whether they surpassed a threshold may be a better measure of treatment success.” Realistic and useful standards for what constitutes risky drinking could serve as an important tool in the effort to curb young-adult drinking to safer levels.

For a pre-print copy of the article, please email



Linden-Carmichael, A. N., Russell, M. A., & Lanza S. T. (In press). Flexibly modeling alcohol use disorder risk: How many drinks should we count? Psychology of Addictive Behaviors.

TVEM Teachers’ Corner: New Resource for Teaching a Methods Course

July 26, 2018:

teacherbox2The TVEM Teachers’ Corner provides resources for instructors who want to incorporate instruction on time-varying effect modeling (TVEM) into methods courses. The download will enable instructors to easily include a presentation and an exercise about TVEM into a class session. The TVEM Teachers’ Corner includes a PowerPoint presentation, two introductory articles for instructors, a SAS exercise (and solution key), and a reading list for students. These items are designed to make comprehending and presenting TVEM as easy as possible.

We also have available a Teachers’ Corner for latent class analysis (LCA).

Download the Teachers’ Corner or read more.

Introduction to Time-Varying Effect Modeling (TVEM) for Graduate Students and Postdoctoral Researchers

June 12,2018:tvem for grads

​We are pleased to offer the workshop, “Understanding Age-Related Changes Using the Time-Varying Effect Model”. TVEM allows researchers use several types of data to model the way associations between variables change over time. The workshop will present the concepts and applications of TVEM in order to give Penn State graduate students and postdoctoral researchers an efficient way to assess TVEM’s potential for their research. Lunch will be included.

Addressing Age-Related Change Using the Time-Varying Effect Model
PRESENTERS: Stephanie Lanza, Director of The Edna Bennett Pierce Prevention Research Center and professor of Biobehavioral Health and Ashley Linden-Carmichael, assistant research professor of Biobehavioral Health
WHEN: Tuesday, July 24, 2018, 10 a.m. – 2 p.m.
WHERE: Bennett Pierce Living Center, 110 Henderson Building

Introduction to TVEM is co-sponsored by the Social Science Research Institute (SSRI), The Methodology Center, and The Edna Bennett Pierce Prevention Research Center and is part of SSRI’s Innovative Methods Initiative. The workshop is FREE and open to all graduate students at Penn State. Registration is required and space is limited. To register, email Tammy Knepp (

The four-hour workshop will include

  • a conceptual introduction to TVEM, a highly flexible approach to estimate dynamic associations between covariates and outcomes;
  • motivating examples modeling age-related changes in substance-use behavior and its correlates;
  • open discussion of how TVEM might be applied in your research; and
  • demonstrations in SAS with sample code to modify for future use.

Who should attend?
We encourage you to register if you are a Penn State graduate student or postdoctoral researcher who wishes to learn more about the way processes unfold over time, and who is interested in addressing questions about age-related change using data from cross-sectional or panel studies.

Questions? Contact Tammy Knepp (

Join Us at SBM

February 27, 2018:sbm

Are you planning to attend the Society for Behavioral Medicine’s 39th Annual Meeting & Scientific Sessions in New Orleans on April 11-14, 2018? If so, schedule some time for some of our many talks, posters, workshops, and more.

April 11

8:30 a.m.—6:00 p.m. Pre-Conference Course
“Novel experimental approaches to designing effective multi-component interventions” Daniel Almirall, Linda Collins, Susan Murphy, Inbal “Billie” Nahum-Shani

8:30 a.m.—11:15 a.m. Pre-Conference Seminar
“Analysis of ambulatory assessment data in behavioral medicine” Stephanie Lanza, Michael Russell

6:30 p.m.—7:30 p.m. Poster Session A
“High-intensity drinking: Prevalence rates across adulthood by gender and race/ethnicity” Ashley Linden-Carmichael

“Biopsychosocial correlates of discrimination in daily life” Lindsey Potter

April 12

10:45 a.m.—11:45 a.m. Midday Meeting
“Lightning rounds with optimization of behavioral and biobehavioral interventions experts: MOST, SMART and MRTs” Daniel Almirall, Linda Collins, Thelma Milenz, Susan Murphy, Inbal “Billie”Nahum-Shani

2:00 p.m.—3:15 p.m. Symposium
“Physical activity and optimization of behavioral and biobehavioral interventions SIGs present: Optimization experiments in the field: The MOST framework through 3 clinical trials” Bonnie Spring, Linda Collins

6:15 p.m.—7:15 p.m. Poster Session B
“Contemporary patterns of marijuana use and attitudes among high school seniors: 2010-2014” Jessica Braymiller

April 13

6:15 p.m.—7:15 p.m. Poster Session C
“Latent Classes of Discrimination among Sexual Minority Adults: Associations with Substance Use Disorders” Cara Rice

April 14

10:00 a.m.—11:00 a.m. Poster Session D
“Exploring quantitative approaches to examining the effect of multiple disadvantaged social status indicators on health” Lindsey Potter

Summer Institute on Analysis of Ecological Momentary Data

January 29, 2018:

We are pleased to announce that Stephanie Lanza and Michael Russell will present this year’s Summer Institute on Innovative Methods, “Analysis of Ecological Momentary Assessment Data Using Multilevel Modeling and Time-Varying Effect Modeling.” During the Summer Institute, Stephanie and Mike will provide attendees with the theoretical background and applied skills necessary to identify and address innovative and interesting research questions in intensive longitudinal data streams such as daily diary and ecological momentary assessment (EMA) data using multilevel modeling (MLM) and time-varying effect modeling (TVEM). By the end of the workshop, participants will have fit several multilevel and time-varying effect models in SAS and will have had the opportunity to fit and interpret preliminary models using their own data.

The Summer Institute will be held June 28 – 29, 2018 on Penn State’s University Park Campus. The Institute is sponsored by Penn State’s Methodology Center and the National Institute on Drug Abuse.

Read more or apply to attend.

Article: Are Drinking and Sexual Behaviors Different for People Who Go to College?

October 18, 2017:sv home

Despite the media coverage and research that have been devoted to risky behavior among young adults, many questions remain about which populations are at risk. In a recent article in Journal of Research on Adolescence, Methodology Center Investigators Sara Vasilenko, Ashley Linden-Carmichael, Stephanie Lanza, and Methodology Center Affiliate Megan Patrick examine differences between college attenders and their non-attending peers in terms of drinking behavior, sexual behavior, and the co-occurrence of heavy drinking and sex. This article also provides a thorough introduction to weighted time-varying-effect modeling (TVEM) and moderation in TVEM.

The authors analyzed data from 11,848 participants in The National Longitudinal Survey of Adolescent to Adult Health (Add Health). They examined whether—and how strongly—sexual behavior was predicted by frequent heavy episodic drinking (HED—occasions when a person has five or more drinks in a row) at different ages from 14-24. As noted above, they also examined whether there was a difference in behavior between college attenders and college non-attenders. They found that the association between HED and sexual behaviors is stronger for college attenders than it is for non-attenders both early in adolescence and during the early college years.

Lead author Sara Vasilenko said, “What I found interesting about this research is that, despite the popular belief that college is a hotbed of risky sexual behavior, college attenders were less likely to engage in risky sexual behavior than their non-attending peers. That said, the association between risky sexual behavior and HED is stronger for attenders than non-attenders from ages 18 to 20. So, while attending college does not appear to lead to greater levels of risky sexual behavior overall, college may be a unique environment for the co-occurrence of drinking and sex.

“In addition to the substantive contributions, this paper demonstrates two different ways to perform moderation in TVEM, and the article includes sample code. This will be useful to researchers who want to learn if time-varying effects differ for different types of people. In this example, we examined the differences between college attenders and non-attenders, but the same technique for dynamic moderation could be applied to any type of moderator.”

Open the article. (Journal access required.)


Vasilenko, S. A., Linden-Carmichael, A., Lanza, S. A. & Patrick. M. E. (in press). Sexual behavior and heavy episodic drinking across the transition to adulthood: Differences by college attendance. Journal of Research on Adolescence.

Learn TVEM: Free, Two-Hour, Online Workshop

January 17, 2017:
Steph presents
We are excited to announce a new series of online workshops. Our 1 & 1 workshops will consist of a one-hour live video presentation on a method followed by a one-hour question-and-answer session with the presenter (and possibly other experts). For our first 1 & 1, Methodology Center Scientific Director Stephanie Lanza will present an introduction to time-varying effect modeling (TVEM) on Tuesday, February 21st, from 3:00 to 5:00 p.m. Eastern Standard Time. After the presentation, she will accept questions via instant message and will answer them through the video connection. This is a great opportunity to learn about the value of TVEM and ask questions to one of the pioneers of applying TVEM to health and behavioral data.

About TVEM

TVEM allows scientists to understand the way relationships change over time. An extension of linear regression, TVEM allows the relationship between two variables to be modeled without making assumptions about the nature of the relationship. The method is flexible enough to be used with many different types of data and can add the dimension of time to analyses where measuring change over time was previously not possible. Read more.

About 1 & 1

The 1 & 1 will be hosted via Zoom video conference at The workshop will be limited to 50 participants, who will be admitted on a first-come, first-served basis when they log on to the video conference the day of the workshop. If you try to attend the workshop but are unable to log on for any reason, please send an email to We hope you will join us to explore this method and our newest way to help researchers adopt cutting-edge research methods.

Video: Introduction to TVEM

October 25, 2016:

We recently released a nine-minute video that provides a conceptual overview of time-varying effect modeling (TVEM). Methodology Center Scientific Director Stephanie Lanza describes two published examples of TVEM and explains how TVEM can be useful with different types of data. This is the second in our new series of instructional videos; a video introduction to latent class analysis is also available.

Watch the video.

Meet us at SPR!

April 25, 2016:MAR-BCB-STL
Come see us at the Society for Prevention Research (SPR) 2016 Annual Meeting, May 31 through June 3 in San Francisco. This year, we will be presenting symposia, talks, posters, and a special interest group on a broad array of topics including time-varying effect modeling, HIV-risk behavior, optimization of interventions, smoking cessation, and much more.

Tuesday, May 31

5:30 – 7:30 p.m. Poster Session I
“Homeless youths’ daily positive and negative support from close friends,” Amanda Griffin.

Wednesday, June 1

12:00 – 1:00 p.m. “Brown bag” special interest group meeting: Optimizing preventive interventions
Discussion about how to apply the multiphase optimization strategy to attendees’ research. Linda Collins, presenter.

4:00 – 5:00 p.m. Roundtable: Using preventive interventions to better understand etiological mechanisms and risk for suicide. Stephanie Lanza, discussant.

5:45 – 7:45 p.m. Poster Session II

  • “Gambling and polysubstance use behavior patterns: Using latent class analysis to examine the syndromal model of addiction,” Bethany Bray.
  • “Motivations for marijuana use among young adults in the U.S.,” Bethany Bray.
  • “‘Gay age’ and recreational drug use among men who have sex with men,” Cara Rice.
  • “First-year college students’ health and well-being: The long-term effects of mindfulness training at 3- and 6-month follow-up,” Kamila Dvorakova.

Thursday, June 2

10:15—11:45 a.m. Individual paper presentations: School-based health-related prevention programs
“Girls just want to know where to have fun: Preventing substance use initiation in an under-resourced community through the leisure-focused Healthwise,” Mojdeh Motamedi.

1:15 – 2:45 p.m.  Organized 20 x 20 presentation: Diverse applications of time-varying effect modeling to answer important questions in prevention science. Michael Russell, chair.

  • “Four definitions of ‘time’ in time-varying effect modeling: Examples in marijuana use” Stephanie Lanza, presenter.
  • “Adolescent e-cigarette use: Age-varying prevalence and association with traditional cigarette smoking,” Michael Russell, presenter.
  • “Sexual behavior and depressive symptoms across adolescence and young adulthood,” Sara Vasilenko, presenter.

3:00 – 4:30 p.m. Organized paper symposium: Three M’s in prevention research: Mediation, multilevel modeling, and missing data. Bethany Bray, discussant.

6:15 – 8:00 p.m. Poster Session III

  • “Time-varying effect of risk-perception on cigarette use among high school seniors,” Jessica Braymiller.
  • “Using engineering methods during intervention design to increase participant engagement,” Emily Waterman.
  • “Free software for data analysis and experimental design from the Penn State Methodology Center,” Bethany Bray will demonstrate and distribute Methodology Center software.

Friday, June 3

8:30 – 10:00 a.m. Organized paper symposium: New insights to prevention sciences from intensive longitudinal data
“Using the time-varying effect model with intensive longitudinal data to inform prevention research,” Sara Vasilenko, presenter.

1:00 – 2:30 p.m. Organized paper symposium: Using big data to inform healthcare utilization, surveillance, and prevention research Stephanie Lanza, discussant.

Featured Articles: Two Types of TVEM

Time-varying effect modeling (TVEM) is a flexible approach that can be used to answer different types of questions using different types of data. Two articles in a recent issue of Drug and Alcohol Dependence demonstrate the range of possibilities for TVEM. In one, a group of researchers led by Michael Mason, associate professor of psychiatry and director of the Commonwealth Institute for Child & Family Studies at Virginia Commonwealth University, examined the time-varying effects of a smoking intervention using ecological momentary assessment (EMA). In the other, Megan Schuler, Marshall J. Seidman Fellow in Health Care Policy at Harvard Medical School, and her co-authors use data from Add Health to examine how the relationship between depression and substance use changes across adolescence and young adulthood. Both articles use The Methodology Center’s TVEM SAS macro for analyses.

In the first article, “Time-Varying Effects of a Text-Based Smoking Cessation Intervention for Urban Adolescents,” the authors examined EMA data from a six-month intervention that sent text messages to 200 urban adolescents who were trying to quit smoking. The authors used TVEM to examine whether the intervention had an impact on the association between stress and craving over time. They found that, during the second and third months, the association between stress and craving was weaker for the intervention group than it was for the control group. They also found that the intervention helped steadily reduce craving over time.  The authors of the article include Methodology Center Investigators Stephanie Lanza and Michael Russell.

Open the “smoking cessation intervention” article. (Journal access required.)

In the second article, “Age-Varying Associations Between Substance Use Behaviors And Depressive Symptoms During Adolescence And Young Adulthood,” the authors used TVEM to examine how heavy episodic drinking (HED), daily smoking, and marijuana use related to depressive symptoms from ages 12 to age 31. HED was associated with depressive symptoms during adolescence, but not afterwards. Both marijuana use and daily smoking were associated with depressive symptoms at most ages from 12 to 31. Megan Schuler, a former postdoctoral fellow in the Prevention and Methodology Training (PAMT) program, worked with Methodology Center Investigators Sara Vasilenko and Stephanie Lanza on the article.

Open the “age-varying associations” article. (Journal access required.)


Mason, M., Mennis, J., Way, T., Lanza, S., Russell, M., & Zaharakis, N. (2015). Time-varying effects of a text-based smoking cessation intervention for urban adolescents. Drug and Alcohol Dependence157, 99-105. doi: 10.1016/j.drugalcdep.2015.10.016

Schuler, M. S., Vasilenko, S. A., & Lanza, S. T. (2015). Age-varying associations between substance use behaviors and depressive symptoms during adolescence and young adulthood. Drug and Alcohol Dependence,157, 75-82. doi: 10.1016/j.drugalcdep.2015.10.005

Interview: Lisa Dierker discusses TVEM and smoking

March 29, 2016:lisad

Methodology Center Investigator and Professor of Psychology at Wesleyan University Lisa Dierker recently sat down to answer a few questions about her research on preventing the uptake of smoking and her interest in time-varying effect modeling.

Methodology Center: How did you become affiliated with the Methodology Center, and what sort of work did you do here?
Lisa Dierker: I was fortunate to meet Linda Collins through her role as a core member of the Robert Wood Johnson Foundation’s Tobacco Etiology Research Network in the early 2000s. At that time, I found myself becoming more and more interested in emerging methodologies and in the opportunities they provided for asking important behavioral health questions. Dr. Collins generously continued working with me as a mentor on my successful K01 award and then invited me to spend a year at the center.

It was an amazing year, arguably the most productive of my career. I was able to collaborate with Drs. Runzi Li and Xianming Tan in the early development of TVEM, learning about the methodology and helping to write substantive papers aimed at showcasing its various features. I also taught a mini course on group-based methods and drew inspiration and ideas from the many connections I was able to make with the center’s large group of talented researchers.

MC: What do you research currently?
LD: My work focuses on understanding the development of cigarette smoking and nicotine dependence. Despite widespread knowledge of the deadly effects of cigarette smoking and advances in prevention and treatment aimed at combating it, smoking continues to be the number one preventable cause of death in the U.S. As a model for understanding addictive behaviors more generally, smoking also represents a relatively common behavior that provides a particularly accessible window into addiction processes across development.

MC: Why is it important to have TVEM in your toolbox?
LD: I spent a good part of my career believing that simply including time-varying variables in my models was adequately addressing the question of time. With the advent of TVEM, I was newly able to consider and investigate questions of real change in the relationships between prominent risk factors and various addiction outcomes in the context of many measurement waves. With TVEM in one’s toolbox, it is possible to move beyond a consideration of effects based on “average change” and instead evaluate how risk may be time varying. In short, TVEM provides a fresh, dynamic look at patterns of change that have been previously inaccessible.

As an example, theories of nicotine addiction emphasize the initial role of positive reinforcement in the development of regular smoking behavior, and the role of negative reinforcement at later stages. We used TVEM on momentary assessment data to test these theories by examining the effects of smoking on mood changes, and how nicotine dependence may moderate this effect. Our work supported the role of positive reinforcement in early stages of dependent smoking, but not the role of negative reinforcement beyond the earliest smoking stages. We have followed this work with a more careful consideration of depression as risk factor for smoking from adolescence through young adulthood.

MC: Outside of your work in smoking, where do you see potential future applications of TVEM?
LD: TVEM holds particular promise for informing the development of both physical and mental health interventions: unlike more traditional regression techniques, it is particularly well positioned to elucidate not only the selection of intervention targets, but also the timing of delivery.