Testing a Health Coaching Program to Help Patients with Obesity Lose Weight—The PROPEL Study [Internet]

Excerpt

Background: Louisiana currently has one of the highest rates of obesity in the United States. Obesity accounts for $2.4 billion in yearly health care expenditures in Louisiana, 42.5% of which is financed by the Centers for Medicare & Medicaid Services (CMS). Obesity disproportionately affects underserved populations, and Louisiana is characterized by high levels of poverty, low health literacy, and food insecurity. The US Preventive Services Task Force recommended that physicians offer intensive multicomponent behavioral interventions to individuals with obesity, and CMS covers intensive behavioral therapy for obesity delivered by a qualified primary care provider (PCP). However, the reliance on PCPs to deliver intensive behavioral therapy for obesity has limitations, creating a critical need to test models that incorporate the 2013 American Heart Association/American College of Cardiology/The Obesity Society guidelines for the management of overweight and obesity in adults in real-life settings for obesity treatment in primary care clinics.

Objectives: The primary aim of this trial was to develop and test the effectiveness of a 24-month, patient-centered, pragmatic, and scalable obesity treatment program delivered within primary care in an underserved population. We hypothesized that relative to patients who received usual care (UC) from their PCP, patients who received an intensive lifestyle intervention (ILI) delivered by health coaches embedded in a primary care setting would have (1) greater percentage reductions in body weight and (2) significant improvements in quality of life (QOL), functional capacity, medical care satisfaction, and obesity comorbidities. Additionally, 3 secondary aims (1) evaluated the relationships between adherence to intervention components and corresponding changes in body weight and secondary outcomes; (2) examined the effects of the intervention on system-level practices and patient satisfaction with care; and (3) tested the heterogeneity of treatment effects (HTE) across clinics and subgroups of patients by sex, age, and race.

Methods: We conducted a cluster randomized controlled trial in which 18 Louisiana primary care clinics were randomized equally to either the ILI or UC group. A total of 803 (452 UC, 351 ILI) adults (67% African American; 65.5% with annual household income of <$40 000) with obesity were enrolled. The UC group received their normal care from their primary care team. The ILI group received a program consisting of weekly sessions in the first 6 months (which represented an active weight loss period), followed by monthly sessions for the remaining 18 months (which represented a weight loss maintenance period), all delivered by health coaches embedded in the clinics. The multicomponent ILI included the provision of portion-controlled foods for the first 4 weeks, shared goal setting for diet and physical activity, and daily weighing on an electric scale with weight loss feedback to the coaches and patients through a computer tracking system. A “toolbox” approach provided specific nutritional, physical activity, and behavioral strategies to choose from depending on the needs of each patient.

The primary outcome was percentage weight loss at 24 months. Secondary outcomes included changes in cardiometabolic disease risk factors, QOL, functional capacity, medical care satisfaction, obesity comorbidities, and HTE across age, sex, and race subgroups. Changes in outcome measurements from baseline to 24 months were analyzed in the context of repeated-measures linear mixed-effects models, which included random cluster (clinic) effects.

Results: Eighteen clinics (9 ILI, 9 UC) enrolled a median of 40.5 (range, 2-89) patients per clinic. Of the enrolled patients, 83.4% completed the 24-month trial. Percentage weight loss at 24 months was significantly greater in the ILI group (−4.99% [95% CI, −6.02% to −3.96%]) than in the UC group (−0.48% [95% CI, −1.57% to 0.61%]), with a mean difference of −4.51% (95% CI, −5.92% to −3.10%) between the groups (P < .0001). Compared with the UC group, significant improvements at 24 months were found in the ILI group for total and high-density lipoprotein cholesterol but not for other cardiometabolic risk factors. Weight-related QOL at 24 months was significantly greater in the ILI group than in the UC group for numerous subscales. Patient satisfaction with medical care did not significantly change within either group.

Conclusions: A high-intensity lifestyle–based obesity treatment program delivered in an underserved primary care population produced clinically significant weight loss and improvements in cardiometabolic risk factors and weight-related QOL over 24 months.

Limitations: Recruitment was lower than originally anticipated (sample size estimates ensured adequate power for all analyses). The sample was composed primarily of women (84.4%), which limited our ability to examine differences in weight loss across sex-by-race subgroups.