
Understanding the reasons why teens start smoking can be easy to recognize; peer pressure, curiosity, and rebellion are among some of the most frequently reported. But what keeps them smoking? The Mayo Clinic reports that the majority of adult smokers start as teens; and researchers know the longer you smoke the more difficult it becomes to quit this life threatening habit. According to Donald Hedeker, professor of biostatistics in the School of Public Health at the University of Illinois at Chicago, “new analytic techniques and approaches to behavior and social science research data are needed”. Currently working as the principal investigator on a research grant funded by the National Cancer Institute, Hedeker aims to develop accessible software for analyzing EMA (ecological momentary assessment) data, and examine the role of teen smoking on mood using data from his program project, Social and Emotional Contexts of Adolescent Smoking Patterns. His study “makes notable methodological and substantive contributions for analysis of EMA data and understanding the relationship between mood variation and smoking dependency”.
EMA allows the research participants to report symptoms, mood, events, and other behaviors as they are happening which allows the researchers the ability to collect more accurate and informative data. Hedeker will be discussing his research in the lecture, “Mood Changes Associated with Smoking in Adolescents: An Application of a Mixed-Effects Location Scale Model for Longitudinal Ecological Momentary Assessment (EMA) Data”. This lecture will be given on February 16 at 4:30 p.m. in Physical Science Center A-wing, room 113.
Hedeker reports that studies using EMA can collect upwards of 30 to 40 observations for each research participant, his presentation will focus on a study of teen smoking using EMA data and how this method can significantly contribute to the research data being collected. According to Hedeker, “these mixed-effects location scale models have useful applications in many research areas where interest centers on the joint modeling of the mean and variance structure”. He states that “these methods can easily generalize to a variety of cancer-relevant research areas, including the assessment of pain and symptoms, as well as diet and exercise”.
Hedeker received his PhD in Quantitative Psychology from UIC in 1989. His main expertise is in the development and use of advanced statistical methods for clustered and longitudinal data, with particular emphasis on mixed-effects models. He is the primary author of four freeware computer programs for mixed-effects analysis: MIXREG for normal-theory models, MIXOR for dichotomous and ordinal outcomes, MIXNO for nominal outcomes, and MIXPREG for counts.
In 2000, Hedeker was named Fellow of the American Statistical Association, the highest honor in his field and was recognized as a University Scholar by UIC that same year. He is an associate editor for Statistics in Medicine and Journal of Statistical Software and has been directly involved in over a dozen NIH or CDC research grants.

