Cost-Effectiveness of Three Doses of a Behavioral Intervention to Prevent or Delay Type 2 Diabetes in Rural Areas

Abstract

Background: Rural Americans have higher prevalence of obesity and type 2 diabetes (T2D) than urban populations and more limited access to behavioral programs to promote healthy lifestyle habits. Descriptive evidence from the Rural Lifestyle Intervention Treatment Effectiveness trial delivered through local cooperative extension service offices in rural areas previously identified that behavioral modification with both nutrition education and coaching resulted in a lower program delivery cost per kilogram of weight loss maintained at 2-years compared with an education-only comparator intervention.

Objective: This analysis extended earlier Rural Lifestyle Intervention Treatment Effectiveness trial research regarding weight loss outcomes to assess whether nutrition education with behavioral coaching delivered through cooperative extension service offices is cost-effective relative to nutrition education only in reducing T2D cases in rural areas.

Design: A cost-utility analysis was conducted.

Participants/setting: Trial participants (n=317) from June 2008 through June 2014 were adults residing in rural Florida counties with a baseline body mass index between 30 and 45, but otherwise identified as healthy.

Intervention: Trial participants were randomly assigned to low, moderate, or high doses of behavioral coaching with nutrition education (ie, 16, 32, or 48 sessions over 24 months) or a comparator intervention that included 16 sessions of nutrition education without coaching. Participant glycated hemoglobin level was measured at baseline and the end of the trial to assess T2D status.

Main outcome measures: T2D categories by treatment arm were used to estimate participants' expected annual health care expenditures and expected health-related utility measured as quality adjusted life years (ie, QALYs) over a 5-year time horizon. Discounted incremental costs and QALYs were used to calculate incremental cost-effectiveness ratios for each behavioral coaching intervention dose relative to the education-only comparator.

Statistical analyses performed: Using a third-party payer perspective, Markov transition matrices were used to model participant transitions between T2D states. Replications of the individual participant behavior were conducted using Monte Carlo simulation.

Results: All three doses of the behavioral coaching intervention had lower expected total costs and higher estimated QALYs than the education-only comparator. The moderate dose behavioral coaching intervention was associated with higher estimated QALYs but was costlier than the low dose; the moderate dose was favored over the low dose with willingness to pay thresholds over $107,895/QALY. The low dose behavioral coaching intervention was otherwise favored.

Conclusions: Because most rural Americans live in counties with cooperative extension service offices, nutrition education with behavioral coaching programs similar to those delivered through this trial may be effective and efficient in preventing or delaying T2D-associated consequences of obesity for rural adults.

Trial registration: ClinicalTrials.gov NCT00912652.

Keywords: Behavioral modification; Cost-effectiveness; Diabetes; Randomized trial; Rural obesity.

Conflict of interest statement

Conflict of interest: There are no conflicts to report.

Copyright © 2020 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

Figures

Figure 1.

Schematic design of the Rural LITE trial, which lasted 104 weeks and was delivered through local Cooperative Extension Service (CES) offices to adults with obesity residing in rural counties. Each X represents a didactic educational session to increase knowledge regarding nutrition, weight loss, and benefits of physical activity. Phase 1, initial weight loss induction, occurred during weeks 1 to 26. Phase 2, extended care for lifestyle maintenance, occurred from weeks 27 to 104. Hemoglobin A1C (HbA1C), the marker of diabetes status captured for this study, was measured at baseline and at the end of phase 2. The number of sessions varied by intervention dose. Sessions delivered to participants in the LOW, MOD, and HIGH dose intervention groups received nutritional education and behavioral coaching to develop skills for long-term weight management. Participants in the education-only comparator intervention (EDUC) received the same educational content and number of sessions as participants assigned to LOW, but without behavioral coaching.

Figure 2.

Schematic design of the Rural LITE trial, which lasted 104 weeks and was delivered through local Cooperative Extension Service (CES) offices to adults with obesity residing in rural counties. This flow diagram illustrates how participant T2D status and year-to-year transitions were modeled for the cost-effectiveness analysis. Measured hemoglobin A1C (HbA1C) values were used to assess each participant’s health state during the study, then modeled for possible transitions from one year to the next for up to 5 years after the intervention ended. Mortality using age-adjusted probabilities was included as a possible absorbing state for the Markov model. The figure indicates that participants could remain in the same state or, unless in the mortality state, transition to any of the other three states from one year to the next.

Figure 3.

Each symbol displays the expected total healthcare costs (in 2015 USD) and Quality Adjusted Life Years (QALYs) for three doses of the Rural LITE intervention that included behavioral coaching with nutrition education (LOW, MOD, HIGH) and an education-only comparator intervention (EDUC). The expected total healthcare costs and QALYs are the averages obtained from the Monte Carlo simulation for 1,000 participants in each group. Expected total costs include both the program costs and healthcare utilization costs over the 5-year time horizon. The education-only comparator intervention, EDUC, had higher expected total costs and lower expected QALYs compared to LOW, MOD, and HIGH.