PATHWEIGH, pragmatic weight management in adult patients in primary care in Colorado, USA: study protocol for a stepped wedge cluster randomized trial

Efficient designs for three-sequence stepped wedge trials with continuous recruitment

BACKGROUND/AIMS

The standard approach to designing stepped wedge trials that recruit participants in a continuous stream is to divide time into periods of equal length. But the choice of design in such cases is infinitely more flexible: each cluster could cross from the control to the intervention at any point on the continuous time-scale. We consider the case of a stepped wedge design with clusters randomised to just three sequences (designs with small numbers of sequences may be preferred for their simplicity and practicality) and investigate the choice of design that minimises the variance of the treatment effect estimator under different assumptions about the intra-cluster correlation.

METHODS

We make some simplifying assumptions in order to calculate the variance: in particular that we recruit the same number of participants, m , from each cluster over the course of the trial, and that participants present at regularly spaced intervals. We consider an intra-cluster correlation that decays exponentially with separation in time between the presentation of two individuals from the same cluster, from a value of ρ for two individuals who present at the same time, to a value of ρ τ for individuals presenting at the start and end of the trial recruitment interval. We restrict attention to three-sequence designs with centrosymmetry - the property that if we reverse time and swap the intervention and control conditions then the design looks the same. We obtain an expression for the variance of the treatment effect estimator adjusted for effects of time, using methods for generalised least squares estimation, and we evaluate this expression numerically for different designs, and for different parameter values.

RESULTS

There is a two-dimensional space of possible three-sequence, centrosymmetric stepped wedge designs with continuous recruitment. The variance of the treatment effect estimator for given ρ and τ can be plotted as a contour map over this space. The shape of this variance surface depends on τ and on the parameter m ρ / ( 1 - ρ ) , but typically indicates a broad, flat region of close-to-optimal designs. The 'standard' design with equally spaced periods and 1:1:1 allocation rarely performs well, however.

CONCLUSIONS

In many different settings, a relatively simple design can be found (e.g. one based on simple fractions) that offers close-to-optimal efficiency in that setting. There may also be designs that are robustly efficient over a wide range of settings. Contour maps of the kind we illustrate can help guide this choice. If efficiency is offered as one of the justifications for using a stepped wedge design, then it is worth designing with optimal efficiency in mind.

A Primary Care-Based Weight Navigation Program

Importance

Evidence-based weight management treatments (WMTs) are underused; strategies are needed to increase WMT use and patients' weight loss.

Objective

To evaluate the association of a primary care-based weight navigation program (WNP) with WMT use and weight loss.

Design, Setting, and Participants

This cohort study comprised a retrospective evaluation of a quality improvement program conducted from October 1, 2020, to September 30, 2021. Data analysis was performed from August 2, 2022, to March 7, 2024. Adults with obesity and 1 or more weight-related condition from intervention and control sites in a large academic health system in the Midwestern US were propensity matched on sociodemographic and clinical factors.

Exposure

WNP, in which American Board of Obesity Medicine-certified primary care physicians offered weight-focused visits and guided patients' selection of preference-sensitive WMTs.

Main Outcomes and Measures

Primary outcomes were feasibility measures, including rates of referral to and engagement in the WNP. Secondary outcomes were mean weight loss, percentage of patients achieving 5% or more and 10% or more weight loss, referral to WMTs, and number of antiobesity medication prescriptions at 12 months.

Results

Of 264 patients, 181 (68.6%) were female and mean (SD) age was 49.5 (13.0) years; there were no significant differences in demographic characteristics between WNP patients (n = 132) and matched controls (n = 132). Of 1159 WNP-eligible patients, 219 (18.9%) were referred to the WNP and 132 (11.4%) completed a visit. In a difference-in-differences analysis, WNP patients lost 4.9 kg more than matched controls (95% CI, 2.11-7.76; P < .001), had 4.4% greater weight loss (95% CI, 2.2%-6.4%; P < .001), and were more likely to achieve 5% or more weight loss (odds ratio [OR], 2.90; 95% CI, 1.54-5.58); average marginal effects, 21.2%; 95% CI, 8.8%-33.6%) and 10% or more weight loss (OR, 7.19; 95% CI, 2.55-25.9; average marginal effects, 17.4%; 95% CI, 8.7%-26.2%). Patients in the WNP group were referred at higher rates to WMTs, including bariatric surgery (18.9% vs 9.1%; P = .02), a low-calorie meal replacement program (16.7% vs 3.8%; P < .001), and a Mediterranean-style diet and activity program (10.6% vs 1.5%; P = .002). There were no between-group differences in antiobesity medication prescribing.

Conclusions and Relevance

The findings of this cohort study suggest that WNP is feasible and associated with greater WMT use and weight loss than matched controls. The WNP warrants evaluation in a large-scale trial.

Evaluation of the Effectiveness of a Bilingual Nutrition Education Program in Partnership with a Mobile Health Unit

There are limited reports of community-based nutrition education with culinary instruction that measure biomarkers, particularly in low-income and underrepresented minority populations. Teaching kitchens have been proposed as a strategy to address social determinants of health, combining nutrition education, culinary demonstration, and skill building. The purpose of this paper is to report on the development, implementation, and evaluation of Journey to Health, a program designed for community implementation using the RE-AIM planning and evaluation framework. Reach and effectiveness were the primary outcomes. Regarding reach, 507 individuals registered for the program, 310 participants attended at least one nutrition class, 110 participants completed at least two biometric screens, and 96 participants attended at least two health coaching appointments. Participants who engaged in Journey to Health realized significant improvements in body mass index, blood pressure, and triglycerides. For higher risk participants, we additionally saw significant improvements in total and LDL cholesterol. Regarding dietary intake, we observed a significant increase in cups of fruit and a decrease in sugar sweetened beverages consumed per day. Our findings suggest that Journey to Health may improve selected biometrics and health behaviors in low-income and underrepresented minority participants.

"We bleed for our community:" A qualitative exploration of the implementation of a pragmatic weight gain prevention trial from the perspectives of community health center professionals

BACKGROUND

Clinical trial implementation continues to shift toward pragmatic design, with the goal of increasing future adoption in clinical practice. Yet, few pragmatic trials within clinical settings have qualitatively assessed stakeholder input, especially from those most impacted by research implementation and outcomes, i.e., providers and staff. Within this context, we conducted a qualitative study of the implementation of a pragmatic digital health obesity trial with employees at a Federally qualified health center (FQHC) network in central North Carolina.

METHODS

Participant recruitment was conducted through purposive sampling of FQHC employees from a variety of backgrounds. Two researchers conducted semi-structured qualitative interviews and collected demographic data. Interviews were digitally recorded, professionally transcribed and double-coded by two independent researchers using NVivo 12. Coding discrepancies were reviewed by a third researcher until intercoder consensus was reached. Responses were compared within and across participants to elucidate emergent themes.

RESULTS

Eighteen qualitative interviews were conducted, of whom 39% provided direct medical care to patients and 44% worked at the FQHC for at least seven years. Results illuminated the challenges and successes of a pragmatically designed obesity treatment intervention within the community that serves medically vulnerable patients. Although limited time and staffing shortages may have challenged recruitment processes, respondents described early buy-in from leadership; an alignment of organizational and research goals; and consideration of patient needs as facilitators to implementation. Respondents also described the need for personnel power to sustain novel research interventions and considerations of health center resource constraints.

CONCLUSIONS

Results from this study contribute to the limited literature on pragmatic trials utilizing qualitative methods, particularly in community-based obesity treatment. To continue to merge the gaps between research implementation and clinical care, qualitative assessments that solicit stakeholder input are needed within pragmatic trial design. For maximum impact, researchers may wish to solicit input from a variety of professionals at trial onset and ensure that shared common goals and open collaboration between all partners is maintained throughout the trial.

TRIAL REGISTRATION

This trial was registered with ClinicalTrials.gov (NCT03003403) on December 28, 2016.

Prelude to PATHWEIGH: pragmatic weight management in primary care

OBJECTIVE

Treatment of obesity-related diseases, rather than obesity itself, remains the mainstay of medical care. The current study examined a novel approach that prioritizes weight management in primary care to shift this paradigm.

METHODS

PATHWEIGH is a weight management approach consisting of staff team training, workflow system management, and data capture from tools built into the electronic medical record (EPIC). PATHWEIGH was compared to standard of care (SOC) using two family medicine clinics in the same US healthcare system. Descriptive statistics compared patient-, provider-, and clinic-level factors between the groups among those with at least one weight-prioritized visit (WPV) and one follow-up weight over 14 months.

RESULTS

Groups were similar in terms of total patient visits (7,353 vs. 7,984) and patients eligible for a WPV (i.e. >18 years + body mass index >25 kg/m2; 3,746 vs. 3,008, PATHWEIGH vs. SOC, respectively). However, more PATHWEIGH clinic patients (15.9% vs. 8.4%; P < 0.001) received at least one WPV. Although no difference was observed for average patient weight loss over 14 months (P = 0.991), the number of WPVs per patient was higher in PATHWEIGH (P < 0.001) and significantly associated with weight loss (P = 0.001), with an average decrease in weight of 0.55 kg per additional visit.

CONCLUSIONS

Results from the current study demonstrate early success in changing the paradigm from treating weight-related comorbidities to treating weight in primary care.

An Assessment of Weight Loss Management in Health System Primary Care Practices

BACKGROUND

Primary care practices can help patients address obesity through weight loss; however, there are many barriers to doing so. This study examined weight management services provided and factors associated with higher reported provision of services.

METHODS

A survey was given to practice members in 18 primary care practices in a Colorado-based health system. The survey assessed weight management services to determine the amount and type of weight loss assistance provided and other factors that may be important. We used descriptive statistics to summarize responses and linear regression with generalized estimating equations to assess the association between the practice and practice member characteristics and the amount of weight management services provided.

RESULTS

The overall response rate was 64% (254/399). On average, clinicians reported performing 73% of the services, and when grouped into minimal, basic, and extensive, the clinicians on average performed 87%, 68%, and 69% of them, respectively. In a multivariable model adjusted for demographics, factors associated with performing more services included perception of overall better practice culture and perception of weight management implementation climate.

CONCLUSIONS

Practice-associated factors such as culture and implementation climate may be worth examining to understand how to implement weight management in primary care.