Food insecurity interventions to improve blood pressure: The healthy food first factorial randomized clinical trial

IMPORTANCE: Food insecurity is associated with worse blood pressure control, but the optimal design for a food insecurity intervention to improve blood pressure is unknown. 

OBJECTIVE: To inform food insecurity intervention design by comparing different intervention elements: type of food resources provided, whether to offer lifestyle counseling, and intervention duration. 

DESIGN, SETTING, AND PARTICIPANTS: A 2 × 2 × 2 factorial comparative effectiveness randomized clinical trial was carried out including adults with hypertension and systolic blood pressure (SBP) of 130 mm Hg or higher, who spoke English or Spanish, and reported food insecurity in 2 clinical networks across 364 clinical sites in North Carolina. 

INTERVENTIONS: Food resources included healthy food subsidy redeemable at grocery stores vs biweekly healthy food box home delivery. The lifestyle intervention included either no intervention or offering telephone-based lifestyle counseling. The intervention duration included 6 months vs 12 months. 

MAIN OUTCOMES AND MEASURES: The primary outcome was SBP. Secondary outcomes were diastolic blood pressure (DBP) and food security. The primary time point was 6 months from randomization. Twelve and 18 months were secondary time points. RESULTS: Overall, 458 individuals were randomized. The mean (SD) age was 49.7 (10.7) years and 345 (75.3%) were female individuals. Fewer than 11 participants identified as American Indian/Alaska Native; 11 (2.4%) identified as Asian, 237 (51.7%) identified as Black, 20 (4.4%) identified with multiple races, fewer than 11 participants identified as Native Hawaiian/Pacific Islander, 165 (36.0%) identified as White, and 22 (4.8%) did not report a racial identity. Twenty two participants (4.8%) identified as Hispanic ethnicity. Mean (SD) preintervention SBP and DBP were 138.2 (11.9) and 87.4 (9.1) mm Hg, respectively. The food subsidy, compared with the food box, led to moderately lower SBP at the 6-month primary time point (132.8 vs 135.3 mm Hg; difference -2.5 mm Hg; 95% CI -4.1 to -0.9; P = .003). DBP was also lower at 6 months (80.5 vs 82.1 mm Hg; difference -1.5 mm Hg; 95% CI, -2.5 to -0.6). The food subsidy group also had lower SBP and DBP at 18 months (SBP difference, -2.1 mm Hg; 95% CI, -4.2 to -0.05; DBP difference, -1.6 mm Hg; 95% CI -2.8 to -0.3). SBP and DBP differences at 12 months were in favor of the food subsidy, but not significantly different. Offering lifestyle counseling did not produce significantly lower SBP or DBP than not offering counseling at any time point. The 12-month duration did not produce significantly lower SBP or DBP than 6-month duration at any time point. 6-, 12-, and 18-month food security scores decreased from baseline in all groups, and did not differ significantly between groups. 

CONCLUSIONS AND RELEVANCE: In this randomized comparative effectiveness trial, a food subsidy produced a moderate reduction in SBP and DBP compared with a delivered food box. Offering lifestyle counseling and a longer benefit duration did not produce better blood pressure outcomes. Food insecurity declined from baseline in all groups, but did not differ between groups.