Abstract
BACKGROUND: Uncontrolled hypertension contributes to disparities in cardiovascular outcomes. Patient intervention strategies informed by behavioral economics and social psychology could improve blood pressure (BP) control in disadvantaged minority populations. OBJECTIVE: To assess the impact on BP control of an intervention combining short-term financial incentives with promotion of intrinsic motivation among highly disadvantaged patients. DESIGN: Randomized controlled trial. PARTICIPANTS: Two hundred seven adults (98% African American or Latino) aged 18 or older with uncontrolled hypertension attending Federally Qualified Health Centers. INTERVENTION: Six-month intervention, combining financial incentives for measuring home BP, recording medication use, BP improvement, and achieving target BP values with counseling linking hypertension control efforts to participants' personal reasons to stay healthy. MAIN MEASURES: Primary outcomes: percentage achieving systolic BP (SBP) < 140 mmHg, percentage achieving diastolic BP (DBP) < 90 mmHg, and changes in SBP and DBP, all after 6 months. Priority secondary outcomes were SBP < 140 mmHg, DBP < 90 mmHg, and BP change at 12 months, 6 months after the intervention ended. KEY RESULTS: After 6 months, rates of achieving target BP values for intervention and control subjects respectively was 57.1% vs. 40.2% for SBP < 140 mmHg (adjusted odds ratio (AOR) 2.53 (1.13-5.70)), 79.8% vs 70.1% for DBP < 90 mmHg (AOR 2.50 (0.84-7.44)), and 53.6% vs 40.2% for achieving both targets (AOR 2.04 (0.92-4.52)). However, at 12 months, the groups did not differ significantly in these 3 measures: 39.5% vs 35.0% for SBP (AOR 1.20 (0.51-2.83)), 68.4% vs 75.0% for DBP (AOR 0.70 (0.24-2.09)), and 35.5% vs 33.8% for both (AOR 1.03 (0.44-2.42)). Change in absolute SBP and DBP did not differ significantly between the groups at 6 or 12 months. Exploratory post hoc analysis revealed intervention benefit only occurred among individuals whose providers intensified their regimens, but not among those with intensification but no intervention. CONCLUSIONS: The intervention achieved short-term improvement in SBP control in a highly disadvantaged population. Despite attempts to enhance intrinsic motivation, the effect was not sustained after incentives were withdrawn. Future research should evaluate combined patient/provider strategies to enhance such interventions and sustain their benefit. TRIAL REGISTRATION: NCT01402453; http://clinicaltrials.gov/show/NCT01402453.