Abstract 4367553: Effectiveness of a Food Pharmacy Program on reducing systolic and diastolic blood pressure in a safety net clinic network

Introduction: Poor diet is a major contributor to hypertension incidence and poor control, contributing to 45% of cardiometabolic deaths. Black and African American communities face the highest burden of hypertension, including higher prevalence, poorer control, and greater mortality. Food as medicine programs, such as food pharmacies, aim to address diet-related health disparities by integrating nutrition into healthcare settings. While these programs are expanding, evidence regarding their effectiveness remains limited. Research Question: Are food pharmacies in safety-net clinics associated with reductions in systolic and diastolic blood pressure? Methods: Between 2017 and 2020, seven safety-net clinics within the San Francisco Health Network (SFHN) established food pharmacies (FPs) across five sites. The FPs took place at clinics and provided healthy groceries, as well as additional components, including cooking demonstrations, recipes, blood pressure (BP) checks, and referrals to other resources. Although the program was open to all patients with hypertension or diabetes, it was intentionally designed for Black patients who experience disproportionate rates of uncontrolled BP. We obtained BP measurements from medical records of participants (n=540) who attended the FP at least once and had at least one BP measurement six months before and six months after their first FP attendance. We used the Callaway-Sant’Anna difference-in-differences approach, designed to accommodate staggered adoption by clinics and participants over time, to estimate the program's average effect among participants, compared with participants who had not yet initiated the intervention as the counterfactual. Results: The FP program was associated with a -3.6 mmHg reduction in systolic BP (95%CI: -5.4, -1.9). The average effect at 12 months was more pronounced in participants attending the FP ≥12 times (-6.2 mmHg, 95%CI: -8.2, -4.2), and those with poor BP control at baseline (systolic: -15.8 mmHg, 95%CI: -18.1, -13.6; diastolic -6.4 mmHg, 95%CI: -7.3, -6.6), with similar effectiveness among Black and non-Black participants. Conclusions: The FP program was effective in reducing BP among patients with hypertension, particularly among those with poor control. Integrating food pharmacies within healthcare systems could improve hypertension management by increasing access to nutritious food and medical care, especially for socially disadvantaged groups.