More rigorous protocol adherence to intensive structured management improves blood pressure control in primary care: results from the Valsartan Intensified Primary carE Reduction of Blood Pressure study

OBJECTIVE To examine protocol adherence to structured intensive management in the Valsartan Intensified Primary carE Reduction of Blood Pressure (VIPER-BP) study involving 119 primary care clinics and 1562 randomized participants. METHODS Prospective criteria for assessing adherence to treatment prescription, uptitration, and visit attendance at 6, 10, 14, and 18 weeks postrandomization were applied to 1038 intervention participants. Protocol adherence scores of 1-5 (least to most adherent) were compared to blood pressure (BP) control during 26 weeks of follow-up. RESULTS Mean age was 59.3 ± 12.0 years, 963 (62%) were men, and 1045 (67%) had longstanding hypertension. Clinic attendance dropped from 91 (week 6) to 83% (week 26) and pharmacological instructions were followed for 93% (baseline) to 61% at week 14 (uptitration failures commonly representing protocol deviations). Overall, 26-week BP levels and BP target attainment ranged from 132 ± 14/79 ± 9 and 51% to 141 ± 15/83 ± 11  mmHg and 19% in those participants subject to the highest (n = 270, 26%) versus least (n = 148, 14%) per protocol adherence, respectively; adjusted relative risk (RR) 1.22 per unit protocol adherence score, 95% confidence interval (CI) 1.15-1.31; for achieving BP target (P < 0.001). Participants with a per protocol score of 4 or 5 (512/1038, 49.3%) were 1.54-fold (95% CI 1.31-1.81; P < 0.001) more likely to achieve their individual BP target compared with usual care. Clinics equipped with a practice nurse significantly influenced protocol adherence (adjusted RR 1.20, 95% CI 1.06-1.37; P = 0.004) and individual BP control (RR 1.21, 95% CI 1.04-1.41; P = 0.015). CONCLUSION There is considerable potential for structured care management to improve BP control in primary care, especially when optimally applied.