Can TElemedicine System Replace Doctor Consultations to Achieve Non-inferior Blood Pressure in Patients With Controlled Hypertension

The goal of this clinical trial is to evaluate whether patients assigned to the telemedicine (HealthCap) group demonstrate non-inferior blood pressure (BP) control compared to patients in the usual care group at 12 months. The main question it aims to answer is:

* Do participants in telemedicine group have non-inferior daytime ambulatory blood pressure readings at 12-month, compared to usual care group?
* Do participants in telemedicine group have better HT treatment, higher self-efficacy, reduced number of visits to primary care clinics and similar health care utilisation other than GOPCs, compared to usual care group?

Participant in telemedicine group will:

* Receive reminders to measure 7-day home blood pressure before their index consultation.
* Get their drug refilled automatically as well as have consultations deferred 16-18 weeks later, if their blood pressure is under optimal control.
* Have consultations as scheduled, if their BP is suboptimal or any of the safety questions screen positive.

Participants in control group will:

* Have consultation with physicians every 16-18 weeks.


Eligibility Criteria:
Inclusion Criteria:

* (i) having a diagnosis of essential HT;
* (ii) on anti-HT medications;
* (iii) well-controlled HT on out-of-office BP measurements, including HBPM or ambulatory blood pressure measurements (ABPM) (measurement algorithm and details under methods). ABPM or HBPM are preferred to office BP due to their superior reproducibility and predictivity to cardiovascular outcomes. Furthermore, office BP misclassifies 30-40% of patients as having suboptimal BP control due to white-coat effect. From our pilot study, some patients with optimal BP are reluctant to undergo ABPM before recruitment into the RCT, and HBPM is more acceptable to these patients and is therefore included. According to local and international guidelines, optimal out-of-office daytime BP should be \&lt;135/85 mmHg for patients without comorbidities and \&lt;130/85 mmHg for patients with comorbidities that increase cardiovascular risk (i.e. stroke, ischaemic heart diseases, heart failure, diabetes mellitus (DM), and chronic kidney diseases) respectively;
* (iv) can read basic Chinese (language used in the HealthCap);
* (v) have used any mobile app (not HT-related) in the previous 1 year; and
* (vii) aged between 18-80.

Exclusion Criteria:

* (i) cannot provide informed consent;
* (ii) unwillingness to conduct HBPM or repeated ABPM;
* (iii) relative contraindications to ABPM (i.e., diagnosed atrial fibrillation, nighttime workers, occupational drivers, or patients with bleeding tendencies);
* (iv) have severe mental illnesses that impair their ability to use HealthCap, including those diagnosed with schizophrenia, dementia, or as being actively suicidal;
* (v) a diagnosis of other acute or chronic diseases that need regular physical assessments and/or medication changes (e.g., suboptimally controlled DM \[e.g., glycosylated haemoglobin (HbA1c)≥7%\], depression requiring medications, active cancer); and (vi) predicted lifespan of \&lt;1 year.