1691-P: Weight Status, Longitudinal Weight Change, and Weight Loss Treatment Utilization among Primary Care Patients with Obesity

Background: Effective weight management treatments (WMTs) include nutrition counseling, very low-calorie (VLC) meal replacement, anti-obesity medications (AOMs), and bariatric surgery. Little is known about how these WMTs influence weight change among individual primary care patients and populations.

Methods: This was a retrospective cohort study using medical record data from one academic health system. Participants were adults with primary care between October 2015 and March 2020. We used serial cross-sections to examine obesity prevalence and WMT use. We used a multistate model to investigate weight trajectories for patients with obesity and no WMT use prior to baseline. This is a time-to-event model with events representing transitions between 5 successive categories of weight change relative to baseline (i.e., ≥10% weight loss, 5-10% weight loss, baseline weight +/-5%, 5-10% weight gain, or ≥10% weight gain). The primary exposures were WMTs; controls were baseline age, BMI, and prior year primary care. Patients with WMT use were propensity matched 1:1 to controls. The primary outcome was the model-based probability of ≥5% weight loss at 1 year.

Results: Among primary patients, the prevalence of obesity increased from 39.2% in 2017 to 40.7% in 2019 (n=138,632); WMT use increased from 2.8% to 8.9% (difference: 6.1%, 95% CI: 5.8-6.4%). In the multistate model (n=10,296), the one-year probability of ≥5% weight loss among patients without WMT exposure was 15.5% [95% CI: 14.8-16.1%]. In contrast, ≥5% weight loss was more likely for patients with year-long exposures to any WMT (nutrition counseling: 23.4%, 95% CI: 21.5-25.3%; VLC meal replacement: 56.4%, 95% CI: 48.7-62.8%; AOMs: 27.8%, 95% CI: 25.1-30.5%; bariatric surgery: 94.4%, 95% CI: 91.1-96.4%).

Conclusions: Use of all WMTs increased the probability of achieving ≥5% weight loss at the individual-patient level but underutilization limits their ability to reduce weight at the population-level.