Baseline Characteristics of PATHWEIGH: A Stepped-Wedge Cluster Randomized Study for Weight Management in Primary Care

Context: Despite the fact that obesity is both treatable and preventable, treating the comorbidities, rather than obesity per se remains the mainstay of therapy.

Objective: To evaluate the efficacy and implementation of a pragmatic approach to weight management in primary care that prioritizes treatment of weight rather than weight-related diseases (PATHWEIGH).

Study Design and Analysis: PATHWEIGH is a hybrid type 1 cluster randomized stepped wedge clinical trial. Clinics were enrolled and randomized to three sequences using covariate constrained randomization. Descriptive statistics were used to summarize clinic and patient characteristics with t-tests, Wilcoxon rank sums or Fisher’s exact tests used to compare groups.

Setting: Fifty-seven primary care clinics in rural, suburban and urban Colorado in a single healthcare system were utilized.

Population Studied: Patients age >18 years and body mass index (BMI) >25 kg/m2 who had a weight-prioritized visit (WPV) in the prior year were enrolled. A WPV was defined as a chief complaint or reason for visit that included “weight”, ICD-10 codes for weight or use of an intake questionnaire for weight.

Intervention: None. This abstract describes the baseline (pre-intervention) characteristics of the clinics and patients treated with standard-of-care (SOC) for weight management.

Outcome Measures: Baseline characteristics of the clinics and patients undergoing a WPV from March 17, 2020 – March 16, 2021.

Results: 20,410 patients met these eligibility requirements representing 12% of patients >18 years and body mass index (BMI) >25 kg/m2 seen at the clinic during this baseline period. The three randomization sequences of 20, 18, and 19 sites were similar with an overall median age of 53 years (IQR: 39-65), 58% women, 76% non-Hispanic whites, 64% commercial insurance, and median BMI of 36 kg/m2 (IQR: 32-41). No sequence differences were seen for vital signs, relevant laboratory values, or numbers of comorbidities or medications that cause weight loss or weight gain. Referral for anything weight-related was low (<6%) and only 334 prescriptions of an anti-obesity medication were noted.

Conclusions: Of patients >18 years and body mass index (BMI) >25 kg/m2 seen in the 57 primary care clinics, 12% had a weight-prioritized visit during the baseline period. Despite most being commercially insured, referral to any weight-related service or prescription of anti-obesity medication was uncommon.