Effect of Smart Phone Based Telemonitoring on Blood Pressure Among Hypertensive Patients in Primary Care

A prospective, block randomized controlled 6 months study comparing the blood pressure control of hypertensive patients who participate in enhanced usual care plus smart phone based telemonitoring (TM) of Blood Pressure (BP) to hypertensive patients receiving enhanced usual care (UC) alone in primary care setting.A previous local study done by Fung et al showed a mean diastolic BP reduction of 3.84 mmHg using manual recording of HBPM after structured program. On the basis of the expectation of least 5 mmHg difference with a power of 90% at a significance of level of 5% assuming a standard deviation of 10 mmHg and accounting for 20% attrition rate, a sample size of 206 was needed. Following the inclusion and exclusion criteria, subjects will be recruited on voluntary basis for this study. Having obtained informed consent, all subjects will be required to attend a structured home blood pressure monitoring education program based on Fung et al study and all are required to pass the self-BP measurement competency test before randomisation.\[1\] All participating subjects will be allocated using block randomization into the intervention group (TM) or control group (UC). Research assistants doing the assessments at baseline, 3 months and 6 months post intervention will be partially blinded to the groupings.At baseline and follow-up visits, research assistants who are blinded to allocation outcomes will measure clinic blood pressure after 15 minutes rest with validated electronic automated sphygmomanometer and conduct the self-efficacy for managing chronic disease scale ( 6-item scale). Four blood pressure readings taken at 1 minute interval will done for each subject and the mean of the 2nd and 3rd readings would be used for the outcome measures at baseline, 3 months and 6 months. For intervention group, patients will be assisted to download a mobile application tool (apps), specifically developed for use in telerecording of readings from home self BP measurement. For the control group, patients will be encouraged on self BP monitoring and keep the BP diary. The research assistants are not blinded in the collection of the mean systolic and diastolic home blood pressure readings readings based on the subjects' paper records for control group or mean systolic and diastolic BP readings sent to the data center at baseline, 3 months and 6 months. Regular home BP monitoring is defined as taking at least 3 or more BP readings per week and documented manually in their paper record or sent electronically through mobile apps to the data center. Comparisons between these two groups in terms of compliance to home BP measurement and readings,proportion of patients doing home BP monitoring,self-efficacy outcomes and improvement in clinic BP readings at 3 months and 6 months post-intervention will be assessed using statistical analysis.Data analyses were conducted using the Statistical package for the Social Sciences (SPSS) version 16.0. Descriptive statistics, including frequency and percentage for categorical variables and mean and standard deviation for continuous variable, were used to describe the demographic characteristics and summarize baseline characteristics of the variables. Independent T-test was used to examine the differences of outcome variables between TM and UC group. A p-value of 0.05 was used as the level of statistical significance. The principal investigator and sub-investigator will do regular monitoring, conduct regular meetings with research team to ensure quality assurance in patient recruitment, data collection, data management, data analysis, reporting for adverse events.