Abstract Body: Methods: A secondary analysis from the Implementation of Multifaceted Patient-Centered Treatment Strategies for Intensive BP Control (IMPACTS) cluster randomized trial in federally qualified health centers in the Gulf South was done. Participants were randomized to intervention (standardized BP measurement education, stepped-care treatment algorithm, team-based care, health coaching, home BP monitoring) versus EUC. Adherence was measured with the Krousel-Wood Medication Adherence Scale-4 item (K-Wood-MAS-4; range 0-4); score<1=high adherence. SBP & diastolic BP (DBP) were assessed with a standard protocol using automated BP devices.
A multivariable mixed effects logistic regression model with group-by-time interaction estimated predicted probabilities of high adherence for each group at each time point; between-group differences were assessed. A multivariable mixed effects linear regression model estimated difference in SBP for high versus low adherence across all time points. Models were adjusted for baseline socio-demographics, SBP, hypertension duration, number antihypertensive drugs, and comorbidities.
Results: Data from 1,272 hypertensive adults from 36 clusters (mean cluster size 35.3, SD 10.6, range 21-60) were analyzed: mean age was 58.3 years (SD 8.9), 56.7% female, 66.5% Black; 62.9% household income <$20K. At baseline, mean SBP & DBP were 147.6 mm Hg (SD 12.5) and 84.6 mm Hg (SD 10.9), respectively; mean K-Wood MAS-4 score was 0.82 (SD 0.89); only 44.3% reported high adherence.
Adjusted percent of high adherence at baseline, 6-, 12- & 18 months: Intervention group: 43% (95% CI 39%, 47%), 53% (95% CI 48%, 57%), 53% (95% CI 49%, 58%) & 54% (95% CI 50%, 59%), respectively; EUC group: 46% (95% CI 42%, 50%), 44% (95% CI 40%, 48%), 48% (95% CI 44%, 53%) & 55% (95% CI 50%, 59%), respectively. Between-group differences in probability of high adherence were higher in intervention versus EUC groups at 6 (p=0.001) & 12 months (p=0.018) but not 18 months (p=0.463). Across all visits, high versus low adherence was associated with mean 4.35 mm Hg lower SBP (p<0.001).
Conclusion: The multifaceted intervention versus EUC increased adherence at 6M and 12M post randomization; higher adherence was associated with lower SBP.