Management of hypertension and multiple risk factors to enhance cardiovascular health - a feasibility study in Singapore polyclinics

High blood pressure (BP) is a leading contributor to cardiovascular mortality globally. There is scarcity of information on effective health systems interventions to lower BP and reduce cardiovascular risk in Southeast Asian countries. We conducted a pilot exploratory trial on 100 adults aged 40 years or older with uncontrolled hypertension to optimize the design for a structured multi-component intervention in primary care clinics for management of hypertension.

Two clinics were involved, each enrolling 50 participants, with one as the intervention clinic and the other as the control (usual care). The intervention comprised the following four components: 1) an algorithm-driven intervention using a fixed-dose combination (FDC) antihypertensive treatment and lipid lowering medication for high risk individuals, 2) subsidized FDC antihypertensive medication; 3) motivational conversation (MC) for high risk individuals; and 4) telephone follow-ups of all individuals. The process outcomes were intervention fidelity measures. The outcomes of change in parameters of interest were healthy lifestyle index (composite score of body mass index, physical activity, dietary habit, dietary quality and smoking), adherence to antihypertensive medications, and systolic and diastolic BP from baseline to follow-up at 3 months.

Greater than 90 % fidelity was achieved for 3 of the 4 intervention components. Although not designed for conclusive results, the healthy lifestyle score increased by 0.16 (±0.68) with the intervention and decreased by 0.18 (±0.75) with usual care (p = 0.02). Adherence to anti-hypertensive medications at follow-up was 95.3 % in the intervention group compared to 83.8 % for usual care (p = 0.01). Systolic and diastolic BP decreased in both intervention and control groups, although statistical significance between groups was not achieved. Hypertensive individuals rated all intervention components ‘highly favorable’ on a Likert scale.

Our findings indicate that the proposed, structured multi-component approach for management of hypertension is feasible for implementation in primary care clinics in Singapore, with some changes to the protocol. The observed improvement in the healthy lifestyle index and adherence to anti-hypertensive medications is promising. A large scale, adequately powered trial would be informative to assess intervention effectiveness on BP and cardiovascular risk reduction.

This trial has been registered at ClinicalTrials.gov. ClinicalTrials.gov number NCT02330224. Registered on 28 December 2014.