Determining Predictors of Weight Loss in a Behavioral Intervention: A Case Study in the Use of Lasso Regression.

Carly Lupton-Smith,Elizabeth A Stuart,Emma E Mcginty,Nae-Yuh Wang,Arlene T Dalcin,Gail L Daumit,Gerald J Jerome

doi:10.3389/fpsyt.2021.707707

Carly Lupton-Smith, Elizabeth A Stuart + Show 5 more

Open Access

https://doi.org/10.3389/fpsyt.2021.707707

Copy DOI

Abstract

ObjectiveThis study investigates predictors of weight loss among individuals with serious mental illness participating in an 18-month behavioral weight loss intervention, using Lasso regression to select the most powerful predictors.MethodsData were analyzed from the intervention group of the ACHIEVE trial, an 18-month behavioral weight loss intervention in adults with serious mental illness. Lasso regression was employed to identify predictors of at least five-pound weight loss across the intervention time span. Once predictors were identified, classification trees were created to show examples of how to classify participants into having likely outcomes based on characteristics at baseline and during the intervention.ResultsThe analyzed sample contained 137 participants. Seventy-one (51.8%) individuals had a net weight loss of at least five pounds from baseline to 18 months. The Lasso regression selected weight loss from baseline to 6 months as a primary predictor of at least five pound 18-month weight loss, with a standardized coefficient of 0.51 (95% CI: −0.37, 1.40). Three other variables were also selected in the regression but added minimal predictive ability.ConclusionsThe analyses in this paper demonstrate the importance of tracking weight loss incrementally during an intervention as an indicator for overall weight loss, as well as the challenges in predicting long-term weight loss with other variables commonly available in clinical trials. The methods used in this paper also exemplify how to effectively analyze a clinical trial dataset containing many variables and identify factors related to desired outcomes.

Highlights

The prevalence of obesity among individuals with serious mental illness (SMI) is substantially higher than that in the overall population [1–6]
Predictors of Weight Loss with psychotropic medications that can cause weight gain as a side effect and possible impairments of memory and functioning, physical inactivity and higher calorie, lower nutrient dense diets in the SMI population can be difficult to combat in order to lose weight [13]
The heightened health risks and obesity experienced by the SMI population combined with their potential functional limitations indicate the necessity for behavioral weight loss interventions tailored to this group

Summary

Introduction

The prevalence of obesity among individuals with serious mental illness (SMI) is substantially higher than that in the overall population [1–6]. This heightened burden of obesity contributes to various health risks, such as hypertension and diabetes mellitus [7–9]. Predictors of Weight Loss with psychotropic medications that can cause weight gain as a side effect and possible impairments of memory and functioning, physical inactivity and higher calorie, lower nutrient dense diets in the SMI population can be difficult to combat in order to lose weight [13]. The heightened health risks and obesity experienced by the SMI population combined with their potential functional limitations indicate the necessity for behavioral weight loss interventions tailored to this group. Identifying early predictors of long-term weight loss can help in the planning of future interventions including potential mid-course adjustments to ensure additional support is provided to those who might need the assistance

Methods

Results

Discussion

Conclusion