Date of Award

Summer 2021

Document Type

Open Access Dissertation


Health Services and Policy Management

First Advisor

Elizabeth Crouch


PURPOSE Historically, African Americans (AA) have been underrepresented in nutritionrelated behavioral research despite their disproportionate higher risk of cardiovascular disease (CVD). The Nutritious Eating with Soul (NEW Soul) Study is one of the first of its kind to recruit an AA only study group to examine CVD prevention via a clinical trial to examine changes in CVD risk factors across two cohorts who are randomly assigned to a plant-based, soul food vegan diet or low-fat omnivorous (omni) diet. The purpose of cost effectiveness analysis (CEA) is to inform clinical and policy decisions and the costs of interventions that society is willing to pay for. However, few studies have examined the cost effectiveness of behavioral interventions for AA adults. The purpose of this study was to evaluate the cost effectiveness of the nutrition and behavior change interventions of the NEW Soul Study, from a societal perspective, by examining direct costs to deliver the intervention, and indirect costs reported by participants associated with intervention adherence.

METHODS Primary data were collected from AA adults (n=105) between the ages of 18-65 from the Midlands SC region, who enrolled in the NEW Soul Study, across two cohorts, and were identified as having overweight or obesity (BMI 25–49.9 kg/m2). Upon completion of baseline assessment of weight, and other laboratory measures, participants were randomized to follow a vegan or low-fat omni diet. A cost effectiveness analysis (CEA) of this randomized control trial is based on one-year outcomes collected in April 2019 for Cohort 1 and June-July 2020 for Cohort 2. An incremental cost effectiveness ratio (ICER) over the one-year study period was calculated based on the intervention (direct) and societal (indirect) costs and weight loss. Total Costs = Costs to deliver the intervention (ingredients for cooking demonstrations, meals) + participants’ average cost of weekly groceries + average weekly costs of dining out. Quality adjusted life year (QALY) was calculated based on Short Form-12 survey responses that were collected at baseline and one year. Variations in weight loss between cohorts 1 and 2 before COVID-19 and during COVID-19 were assessed using a difference-in-difference (DD) study design.

CONCLUSIONS The vegan diet intervention produced clinically relevant weight loss at a lower cost and was therefore cost-effective. Both diet groups experienced similarly minimal gains in QALYs and the DD in QALYs between the vegan and omni groups was not statistically significant. DD analysis suggests that the COVID-19 pandemic had an impact on participants’ ability to achieve greater weight loss in Cohort 2 (compared to Cohort 1), and significantly inhibited weight loss of participants in the vegan diet group.