Momentary Influences on Self-Regulation in Two Populations With Health Risk Behaviors: Adults Who Smoke and Adults Who Are Overweight and Have Binge-Eating Disorder

Dynamic structural equation models with binary and ordinal outcomes in Mplus

Intensive longitudinal designs are increasingly popular, as are dynamic structural equation models (DSEM) to accommodate unique features of these designs. Many helpful resources on DSEM exist, though they focus on continuous outcomes while categorical outcomes are omitted, briefly mentioned, or considered as a straightforward extension. This viewpoint regarding categorical outcomes is not unwarranted for technical audiences, but there are non-trivial nuances in model building and interpretation with categorical outcomes that are not necessarily straightforward for empirical researchers. Furthermore, categorical outcomes are common given that binary behavioral indicators or Likert responses are frequently solicited as low-burden variables to discourage participant non-response. This tutorial paper is therefore dedicated to providing an accessible treatment of DSEM in Mplus exclusively for categorical outcomes. We cover the general probit model whereby the raw categorical responses are assumed to come from an underlying normal process. We cover probit DSEM and expound why existing treatments have considered categorical outcomes as a straightforward extension of the continuous case. Data from a motivating ecological momentary assessment study with a binary outcome are used to demonstrate an unconditional model, a model with disaggregated covariates, and a model for data with a time trend. We provide annotated Mplus code for these models and discuss interpretation of the results. We then discuss model specification and interpretation in the case of an ordinal outcome and provide an example to highlight differences between ordinal and binary outcomes. We conclude with a discussion of caveats and extensions.

Trajectories of therapeutic skills use and their dynamic relations to symptom change during cognitive-behavioral therapy for bulimia nervosa

OBJECTIVE

To examine trajectories of therapeutic skills use and weekly relations between skills use and symptom change during the enhanced version of cognitive-behavioral therapy (CBT-E) for bulimia nervosa (BN).

METHOD

Fifty-five adults (M age: 39.0 ± 14.1; 83.9% female; 64.3% White, 93.6% non-Hispanic/Latino) receiving CBT-E for BN-spectrum eating disorders (EDs) self-monitored their use of five therapeutic skills (i.e., regular eating, eating enough to prevent excessive hunger and eating a range of macronutrients, breaking dietary rules, urge management strategies, and mood management strategies) several times per day during treatment. Patients also self-reported their ED symptoms (i.e., frequency of binge eating, compensatory behaviors, and dietary restraint) weekly. We examined trajectories of use of each CBT-E skill and temporal relations between skills use and ED symptoms from week-to-week during treatment.

RESULTS

Participants showed significant increases in eating enough to prevent excessive hunger and eating a range of macronutrients from week-to-week (p < .05). Regular eating, eating enough to prevent excessive hunger, and eating a range of macronutrients 1 week predicted lower binge eating and compensatory behaviors the same week and the following week, and urge management strategy use predicted greater binge eating the same week and the following week (p < .05).

CONCLUSIONS

Results showed temporal relationships between therapeutic skills use and symptom change on a weekly level, with evidence that using skills targeting dietary restraint was associated with lower BN symptoms. Findings highlight the promise of future work to elucidate the most potent CBT-E skills for symptom improvement and inform more targeted interventions.

PUBLIC SIGNIFICANCE

Findings showed weekly relationships between therapeutic skills use and symptom change during treatment, with evidence that using CBT-E skills aimed to reduce dietary restraint (i.e., regular eating, eating enough to prevent excessive hunger, and eating a range of macronutrients) was associated with lower BN symptoms. Future work has the potential to identify the most potent CBT-E skills for symptom improvement and inform more targeted interventions.

Synergistic Opportunities for Affective Science and Behavior Change

Behavior change can be challenging to facilitate and achieve. Behavior change frameworks largely focus on social cognitive determinants, omitting affective determinants or including them in a superficial way. However, evidence points to the role of affect in decision-making and behavior, particularly when the behavior at focus for change is affectively pleasant or when the behavior to be facilitated is affectively unpleasant. This paper identifies challenges and opportunities to further affective science by using behavior change as a context and, relatedly, to further the science of behavior change by leveraging theoretical and methodological innovations in affective science.