Management of hypertension and multiple risk factors to enhance cardiovascular health in Singapore: The SingHypertension cluster randomized trial

Background: Hypertension is a serious public health problem in Singapore and is associated with significant morbidity and mortality from cardiovascular disease (CVD) with considerable implications for health-care resources. The goal of the trial is to compare a multicomponent intervention (MCI) to usual care to evaluate the effectiveness and cost-effectiveness of the MCI for lowering blood pressure (BP) among adults with uncontrolled hypertension in Singapore primary-care clinics. Methods/design: The study is a cluster randomized trial in eight polyclinics in Singapore: four deliver a structured MCI and four deliver usual care. The components of the MCI are: (1) an algorithm-driven antihypertensive treatment for all hypertensive individuals using single-pill combination (SPC) and lipid-lowering medication for high-risk hypertensive individuals, (2) a motivational conversation for high-risk hypertensive individuals, (3) telephone-based follow-ups of all hypertensive individuals by polyclinic nurses, and (4) discounts on SPC antihypertensive medications. The trial will be conducted with 1000 individuals aged >= 40 years with uncontrolled hypertension (systolic BP >= 140 mmHg or diastolic BP >= 90 mmHg, based on the mean of the last two of three measurements) in eight polyclinics in Singapore. The primary outcome is change in systolic BP from baseline to follow-up at 24 months post-randomization. The incremental cost of MCI per CVD disability adjusted life years (DALY) averted and quality adjusted life years (QALY) saved will be computed. Discussion: The demonstration of an effective and cost-effective hypertension control program that is implementable in busy polyclinics would provide compelling evidence for upscaling the program across all primary-care centers in Singapore, and possibly other regional countries with a similar health-care structure.