Associations of Program Adherence and Motivation with Blood Pressure Reduction in a Digital Therapeutic for Hypertension: The B-INDEX Study.

BACKGROUND: Although digital therapeutics (DTx) have shown efficacy for reducing the blood pressure (BP) of individuals with hypertension, the relative contributions of program adherence (objective) and patient motivation (subjective) to the antihypertensive effects of DTx remain unclear. METHODS: We analyzed data from the B-INDEX (Behavioral Modification Index) study, evaluating the BP-lowering effects by DTx. Program adherence was quantified using app-based usage metrics. Questionnaires assessed the DTx users' motivation. Associations between these factors and systolic BP (SBP) reduction were examined. RESULTS: Among 198 patients with hypertension (mean age 54.9 ± 10.6 years, 57.1% male, mean body mass index 26.7 ± 5.3 kg/m2, 57.6% taking antihypertensives), higher program adherence was associated with greater reductions in SBP at Week 24 (-8.0 vs -2.5 mmHg, p < 0.001), whereas higher motivation scores showed no significant association with SBP reduction (-7.3 vs -5.6 mmHg, p = 0.257). In contrast, body weight reduction and improvements in salt-intake scores showed similar patterns across adherence- and motivation-based subgroup analyses. CONCLUSIONS: Motivation is important for lifestyle modification, but objective program adherence was more strongly associated with SBP reduction than subjective motivation. Objective behavioral indices may better reflect lifestyle changes relevant to the antihypertensive effects of DTx. CLINICAL TRIAL REGISTRATION: UMIN000050479 (https://www.umin.ac.jp/ctr/).