Summer Institute on Latent Class Analysis (LCA)
We are pleased to announce that Methodology Center Investigators Stephanie Lanza and Bethany Bray will present this year’s Summer Institute on Innovative Methods, “Introduction to Latent Class Analysis.”
Sponsored by the Methodology Center and the National Institute on Drug Abuse, the 18th Summer Institute will present the theoretical background and applied skills needed to address interesting research questions using latent class analysis (LCA). By the end of the workshop, participants will have fit preliminary latent class models to their own data. The institute will be held on June 27-28, 2013 at Penn State in State College, PA. Apply early; there are a very limited number of seats available.
Read more or apply.
Teens Becoming Regular Smokers: The Roles of Smoking Quantity and Nicotine Dependence
Nicotine dependence plays a central role in the development of regular smoking, but the relationship is reciprocal: nicotine dependence causes people to smoke more, and regular smoking leads to nicotine dependence. To understand how people become regular smokers, it is important to understand the roles that nicotine dependence and smoking quantity play in the frequency of smoking, and how the strengths of these relationships change over time. This issue is addressed in the article in Drug and Alcohol Dependence, “Time-varying effects of smoking quantity and nicotine dependence on adolescent smoking regularity,” by Arielle Selya, Lisa Dierker, Jennifer Rose, Donald Hedeker, Xianming Tan, Runze Li, and Robin Mermelstein.
Read about the time-varying effects of factors that influence smoking.
New Software: LCA Stata Plugin
The Methodology Center is pleased to announce our first software release compatible with Stata, the LCA Stata Plugin for conducting latent class analysis (LCA). The software is available for download free of charge from the Methodology Center website. The LCA Stata Plugin is based on version 1.2.7 of PROC LCA for SAS (also developed by the Methodology Center) and includes the same functionality.
Stata Plugin Features:
- multiple-groups LCA
- LCA with covariates (prediction of latent class membership)
- posterior probabilities available in output
- sampling weights and clusters can be incorporated
The software has a full users’ guide. Please email email@example.com with any questions.
Download the software or read more.
Comparing Approaches to Causal Mediation Analysis
At the Causal Mediation Symposium in Ghent, Belgium, in January, Methodology Center Principal Investigator Donna Coffman presented the talk, “Comparison of Three Approaches to Causal Mediation Analysis.” Causal mediation analysis can be used to examine the mechanisms through which behavioral health interventions work, even when randomization is not possible or ethical. In her talk, Donna examined how different causal mediation methods perform when the assumptions of each are violated. She recommends that researchers carefully define their scientific questions and select a method that relies on assumptions that are plausible for their data.
Download the slideshow.
Read about Center work on causal mediation.
Pilot Project: Reducing Drinking Through Daily Physical Activity
Methodology Center Collaborative Research Funding has been awarded to David Conroy, Professor of Kinesiology and Human Development & Family Studies at Penn State. He will work with Nilam Ram and Methodology Center Investigators Runze Li, Stephanie Lanza, and Linda Collins to design an intervention that encourages physical activity among heavy drinkers in order to reduce alcohol consumption. Researchers believe that some forms of physical activity can reduce alcohol intake by enhancing enjoyment, improving mood, occupying time, and reducing reactions to stress. This project will address several unanswered questions about the relationship between physical activity and alcohol consumption and will use cutting-edge intervention-design methods to build an effective and efficient intervention.