Abstract Body (Do not enter title and authors here): Background
We evaluated the efficacy of a digital health program integrating self-measured blood pressure (BP) monitoring and lifestyle coaching in managing hypertension (HTN). Conducted from 2019 to 2022 across 39 healthcare facilities in 10 US states, using Bluetooth-enabled devices, mobile apps, and a care coordination platform, longitudinal BP data was collected.

Methods
Linear mixed models with patient-specific random intercepts assessed within-subject BP changes. Causal modeling evaluated BP improvement by adherence level, measured by the regularity and frequency of BP measurements in the first 6 months, adjusting for covariates including age, gender, BMI, and medication compliance. To assess the patient adherence to the impact on BP outcomes in the long term we also analyzed those with data at baseline and endpoints from 6 to 24 months.

Results
We analyzed 5520 patients with baseline HTN II (SBP/DBP: 152.6 ± 12.7 / 87.6 ± 10.5 mmHg, mean± SD), 51.3% female, 43.3% in 65-80yr and 34.9% in 46-65yr. BP change at 6 months was -12.5 ± 16.9 / -6.9 ± 10.0 (N = 4171, p<0.001); at 12 months, -13.1 ± 17.3 / -7.5 ± 10.0 (N = 2625, p<0.001); and at 24 months, -14.1 ± 17.8 / -8.0 ± 10.4 (N = 1424, p<0.001). Regression analysis accounting for covariates showed steep initial reductions (-0.4 mmHg/week, p<0.001 for 0-6 months) with continued reductions of diminished magnitude with further follow-up (-0.07 mmHg/week, p<0.001 for 7-24 months). Causal modeling demonstrated that higher program adherence was linked to significantly greater reductions in SBP. Those with the highest adherence had greater reductions in SBP vs. those with the lowest adherence at both 6 months (-16.3 vs. -6.1, p<0.001) and 24 months (-17.1 vs. -11.4, p<0.001). Patients in the lowest adherence group (N = 1145, 3.7 ± 2.3 BP measurements/week with 3.0 weeks of gap between measurement weeks) also showed significant reductions in BP with 24.0% and 41.4% controlled (<140/90 mmHg) at 6 and 24 months respectively.

Conclusions
The digital BP monitoring program significantly improved self-measured BP control in HTN stage II patients. Causal modeling showed that longer-term remote monitoring was linked to greater reductions in BP. Greater adherence to self-measurement led to greater reductions in BP, while the minimal adherence group also showed significant improvement, underscoring the program's effectiveness in long-term cardiovascular health management in a population with diverse engagement levels.