1. Background:
Cardiovascular diseases (CVD) are the leading cause of disability and death in Singapore, and consume substantial healthcare resources. Uncontrolled hypertension confers the highest attributable risk of CVD. About one in four adults suffer from hypertension in Singapore, 50% of them have uncontrolled blood pressure (BP), and management is especially sub-optimal among those with concomitant diabetes or dyslipidemia. Evidence suggests that well structured programs of care delivery are effective in lowering BP and preventing CVD. However, there is lack of empirical data on such strategies in Singapore.
The findings of the pilot will inform the design of a larger cluster randomized trial in eight polyclinics in Singapore. If proven effective in the main study, the information will be valuable in convincing the policy-makers to upscale strategies for enhancing management of hypertension and cardiovascular health within the primary health infrastructure of Singapore, and possibly neighbouring Southeast Asian countries.
2. Aims:
Specific aim 1: To explore logistics for delivery of provider training in intervention algorithm and motivational counselling while maintaining optimal efficiency of ongoing clinical work at the polyclinics.
Specific aim 2: To establish recruitment of participants in the intervention and usual care groups, and uptake of each component of the multicomponent intervention.
Specific aim 3: To establish mechanism for capture and retrieval of the relevant clinic visit data (physician and nurses records, pharmacy and laboratory including costs) at the polyclinic, and telephone follow-ups, hospitalization and related costs.
Specific aim 4: To explore impact of intervention vs usual care on change in BP in the short term.
Specific aim 5: Identify appropriate methods for capturing potential adverse events and safety endpoints related to intervention.
3. Study Design: It is a non-randomized community intervention trial designed to test feasibility of structured multi-component intervention in polyclinic setting.
4. Setting: The study involves two polyclinics in Singapore. One delivers intervention and one delivers usual care.
5. Study population: The polyclinics have a system in place such that all patients with hypertension get a "panel" of fasting blood and urine tests at subsidized cost at the time of initial diagnosis and then annually. The individuals visiting polyclinic for their initial (or annual) panel of laboratory tests marked as "hypertension panel" will be screened for eligibility and recruited if eligible. One hundred patients (50 per polyclinic) will be recruited and followed for 3 months.
6. Intervention: Orientation training sessions will be organized for all physicians, nurse practitioners (NP) and nurses in the polyclinic assigned the intervention which is comprised of 3 components
1. Structured treatment algorithm with fixed dose antihypertensives for high risk patients: The training curriculum including treatment algorithm has been prepared by a team of nephrologists, cardiologists and pharmacologists in consultation with primary care physicians and Clinical Cardiovascular Work Group, using the case method, aiming for global cardiovascular risk reduction.
2. Motivational conversation by NPs and nurses for high risk patients at baseline: Separate training sessions will be conducted for NP and nurses. NP and nurses will receive training on motivational conversation techniques and communication strategies from a trainer skilled in communication in health care. These nurse and nurse practitioners will provide motivational conversation sessions to high CVD risk patients at baseline.
3. Structured follow-up over telephone and in Clinics: NPs and nurses in intervention polyclinic will be proactive in follow-up of their patients for self-monitoring of BP and providing advice for adherence to treatment every 4 weeks for the duration of the project (3 months). A communication checklist for the follow-up will be incorporated to the existing follow-up system. Information on adverse events will be obtained and action plan will be communicated with patients (discontinue the suspected drug and arrange visit to clinic, as appropriate).
7. Usual Care: The health providers in the polyclinic with usual care will continue their existing practices.
8. Outcomes assessment: Final outcome assessment will take place three months after baseline. The outcomes assessors will also call the patients over telephone for outcomes assessment at week 6 after baseline. Information on self-monitoring of BP, recommended life style change, self-care, and medication use (including herbal and traditional Chinese) will be collected.
The outcome assessors will also extract process outcomes measures from the general practitioner (GP) and nurses' notes. These will include number and duration of contact with the patient (whether in person or by phone), changes in prescribed medication and dose, and reporting of any adverse events from medications.
9. Sample size calculation: Sample size was calculated using Stata version 12. A sample size of 90 (45 in each group) achieves 80% power to detect 5 mmHg difference in systolic BP change from baseline to end of follow-up in intervention group compared to usual care group, with an estimated standard deviation (SD) of 9.5, significance level of 0.05 using a two-sided two-sample t-test. Assuming that there could be 10% drop out rate, we plan to take the total sample size of 100 subjects. At least 152 eligible subjects (72 in each group) would be necessary to attain at least 66% recruitment rate.
